Rail Engineer - Issue 190 - May-June 2021

by rail engineers for rail engineers

MAY-JUN 2021 – ISSUE 190

Colne Valley Viaduct

PICCADILLY LINE TRAINS

Can Scotland deliver its aspiration of a zero-carbon railway by 2035?

We take a journey from 1891 to 2025 on a variety of tube stock. www.railengineer.co.uk

PERMANENT WAY & LINESIDE ASSETS

DECARBONISING SCOTLAND

ELECTRIFICATION & POWER

We delve through the findings of two reports commissioned following the tragic derailment.

FOCUS FEATURES

LEARNING FROM CARMONT

EARTHWORKS GEOTECHNICS & CONCRETE

HS2’s LARGEST BRIDGE

46 CONTENTS

ARTICLE SPONSORED BY

PHOTO: JUI-CHI CHAN

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Winning Dawlish’s coastal battles

Mark Phillips visits the Devon seaside to witness the continuing fight against nature’s irrepressible forces.

Piccadilly Line trains

Malcolm Dobell takes a journey from 1891 to 2025 on a variety of tube stock, in advance of Siemens’ new trains arriving.

Decarbonising Scotland’s railway

Can Scotland’s aspiration of a zero-carbon railway be delivered by 2035, substantially through electrification?

A big step forward

Clive Kessell checks out the trackside switches improving safety around the isolations on DC lines.

Overcoming the clearance issue 56

Peter Stanton considers electrification clearances and the inventive solution minimising infrastructure rebuild costs.

Bringing all tracks together

The DC-DC converter offering a one-size-fits-all solution for all voltages and classes of trains.

Focus on decarbonisation

ARQ becomes an integrated self-delivery model for UK electrification delivery.

Providing 4G radio on London Underground

Why does your mobile still work on subterranean sections of the Jubilee Line? We venture beneath the capital to find out.

In search of hidden shafts

On the West Coast Main Line, engineers grout behind a tunnel lining to mitigate the risks from its construction legacy.

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HS2’s largest bridge

Bob Wright examines the challenges involved in constructing Colne Valley Viaduct across a river, canal and reservoirs.

Learning from Carmont

David Shirres delves through the findings of two reports commissioned following the Carmont derailment.

Cutting edge monitoring

Grahame Taylor checks out the equipment keeping a watchful eye on our infrastructure in case the earth moves.

The slippery slope

Paul Darlington looks back at the emergence of our earthworks management regime following rail privatisation.

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Instrumentation and monitoring

Many significant technologies have come to the aid of asset managers, not least wireless remote condition monitoring.

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The trackside conduit

We venture historically down the lineside to examine how we contain the railway’s vital cabling.

A model for containment

The GRP system offering enhanced protection for cables.

Back to the future

How the permanent way evolved into a well-engineered guided transport system that’s hard to beat.

Longer-life crossings

How design and service improvements will reduce the number of crossings breaking in traffic.

Get a grip

Efforts to overcome the seasonal problem of low adhesion under braking continue to pay dividends.

An innovative innovation conference

RIA’s recent gathering was an online affair, but the information and insights it provided were not diminished.

Gauge clearance software: an unavoidable pain?

Gauging engineers and software specialists have combined their skills to create a revolutionary new assessment system.

Level crossings: delegation of responsibility

Colin Wheeler checks out new efforts to support the assessment and control of level crossing risks.

Peak performance

A snapshot of the projects delivered by the railway’s energetic workforce over recent bank holidays.

Rail Engineer | Issue 190 | May-Jun 2021

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EDITORIAL EDITORIAL

A new future The Great British Railways organisation to be created under the Williams-Shapps plan will run the rail network, manage its infrastructure, procure passenger services and produce timetables. Thus, the whole railway will be under a single national leadership, providing a whole-system view to eliminate perverse incentives and do what is best for passengers and freight customers.

Not surprisingly, most of the plan’s press coverage concerned its new deal for passengers which includes simplified fares and new flexible season tickets. Yet, for railway engineers, the section on ‘accelerating innovation and modernisation’ is perhaps of greatest interest. This notes that no organisation currently has the overall authority to implement programmes across the wheel/rail interface such as digital signalling. It also commits to publishing a long-term strategy next year to set out the whole rail network’s key strategic priorities for the next 30 years.

Williams-Shapps has much to commend it. However, it does not address the requirement for an informed client organisation to advise Ministers and provide strategic direction to ensure that Britain can get the best from its rail network. The need for such a body is indicated by erroneous UK Government pronouncements on rail decarbonisation. For example, Network Rail’s Traction Decarbonisation Network Strategy concluded that rail decarbonisation requires electrification of 85% of the unelectrified network. Yet the Williams-Shapps plan states that “electrification is likely to be the main way of decarbonising the majority of the network” and falsely attributes this comment to TDNS. Acting as an informed client, Transport Scotland has persuaded Scottish Ministers that large-scale electrification is essential for both rail decarbonisation and the long-term sustainability of the rail business. As well as being cheaper to buy and run, electric trains drive the required modal shift to rail as they attract more passengers and enable longer freight trains to run at higher speeds, resulting in more trains on existing infrastructure.

Our feature on decarbonising Scotland’s railway describes how Transport Scotland, Network Rail and ScotRail are now delivering a programme to make the Scottish rail network net-zero carbon by 2035. To do so, there is an integrated long-term infrastructure,

Rail Engineer | Issue 190 | May-Jun 2021

rolling stock and timetable strategy which will provide a steady programme of work for the supply chain. As well as electrification, this infrastructure work includes freight gauging and capacity enhancements.

Thus, the way ‘Team Scotland’ has developed its strategic plan and is working together to deliver it - is a foretaste of the new way of working that the Williams-Shapps review intends to promote.

The need for urgent action on the climate emergency was tragically underscored by the Carmont accident. This was caused by a severe storm overwhelming a drain installed just ten years ago. Whilst the final RAIB report will consider the design and construction of this drain, much has already been learnt. As we describe, the comprehensive reports produced by the earthworks and weather task forces established by Network Rail after this

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THE TEAM Editor David Shirres david.shirres@railengineer.co.uk

Acting Production Editor Graeme Bickerdike graeme.bickerdike@railengineer.co.uk

Production and design Adam O’Connor adam@rail-media.com Matthew Stokes matt@rail-media.com

Engineering writers bob.wright@railengineer.co.uk clive.kessell@railengineer.co.uk collin.carr@railengineer.co.uk david.bickell@railengineer.co.uk graeme.bickerdike@railengineer.co.uk grahame.taylor@railengineer.co.uk lesley.brown@railengineer.co.uk malcolm.dobell@railengineer.co.uk

accident offer clear lessons to reduce risk from earthworks failures.

Grahame Taylor describes how state-ofthe-art monitoring systems are one way of reducing this risk whilst Paul Darlington’s feature on earthworks asset management highlights the importance of good drainage.

Both these features consider how most railway earthworks were built in the 1800s when there was little understanding of the science of soil mechanics.

At Dawlish, the climate threat is from the sea. Mark Phillips describes how a new sea wall is designed to give 100 years resilience and is being constructed between the tides. Another problematic legacy of historic infrastructure is hidden tunnel shafts. Bob Wright investigates how those in Shugborough Tunnel were identified and stabilised. In contrast, he also explains how HS2 is to use the latest construction techniques to build Britain’s longest railway viaduct over the Colne Valley, west of London.

With its long history, the permanent way has benefited from years of experience, research and development to provide the most efficient form of transport in respect of capacity and low rolling resistance of steel wheel on steel rail. However, with the resultant tiny contact area comes the

DAVID SHIRRES

RAIL ENGINEER EDITOR

challenge of rail adhesion. Our feature on an RSSB ADHERE 2021 webinar reports progress on adopting recently developed solutions.

When designing their new ‘Inspiro’ trains for London Underground, Siemens had the challenge of designing more spacious walkthrough trains for the Piccadilly Line’s 3.66m diameter tubes. Malcolm Dobell explains why the solution involved there being no wheels on four cars of these nine-car units.

Limited tunnel space was also a problem for the pilot project to trial the use of 4G radio on the Jubilee Line. Clive Kessell describes its challenges and potential benefits.

The Railway Industry Association’s innovation conference showcased many worthwhile innovations and the research capabilities that the UK Rail Research and Innovation Network has to offer. This included initiatives to reduce electrification cost, such as the surge arrestors described in Peter Stanton’s article. Despite this being a virtual event, the information and insights were in no way diminished.

Williams-Shapps, strategic decarbonisation delivery and managing earthworks are amongst the big-picture issues we cover this month. Yet let’s not forget that infrastructure repair and enhancement work is done on a 24/7 basis in all weathers. Our round up of the £196 million worth of engineering work at 7,500 worksites over Easter and the May bank holiday weekend is typical of what that involves.

mark.phillips@railengineer.co.uk paul.darlington@railengineer.co.uk peter.stanton@railengineer.co.uk stuart.marsh@railengineer.co.uk

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Rail Engineer | Issue 190 | May-Jun 2021

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NOTICES

Making the case for electrification

The Railway Industry Association (RIA) launched its latest electrification report on 22 April by sending it to Grant Shapps, Secretary of State for Transport, with a covering letter signed by 17 industry bodies. In it they described how the ‘Why Rail Electrification?’ report complemented Network Rail’s Traction Decarbonisation Network Strategy by explaining why rail electrification is a future-proofed technology with a strong business case and, for most of the unelectrified network, is the only way of decarbonising rail traction.

The Railway Industry Association (RIA) launched its latest electrification report on 22 April by sending it to Grant Shapps, Secretary of State for Transport, with a covering letter signed by 17 industry bodies. In it they described how the ‘Why Rail Electrification?’ report complemented Network Rail’s Traction Decarbonisation Network Strategy by explaining why rail electrification is a future-proofed technology with a strong business case and, for most of the unelectrified network, is the only way of decarbonising rail traction.

The report’s lead author was Rail Engineer’s Editor, David Shirres, who was concerned that comments made by some politicians showed a lack of understanding of the basics of rail traction. Whilst much has recently been written about rail decarbonisation, there is little explanation of why electrification delivers its claimed benefits. Yet the case is more likely to be accepted if decision-makers could

understand that feeding electricity from the grid directly into a train’s motors must always be more efficient than self-powered traction with its associated storage and energy-conversion inefficiencies.

After discussing this with others, it was suggested that Shirres should produce an ‘electrification manifesto’ paper with the support of Noel Dolphin, Head of UK Projects for Furrer+Frey, Garry Keenor, Atkin’s Group Engineer (OLE) and Paul Hooper, Atkin’s Technical Director.

The report is based on articles featured in Rail Engineer. It examines how the railway can achieve net-zero carbon in the context of overall UK decarbonisation and considers future electricity supplies, the hydrogen economy, the limited role of biofuels and synergies with other sectors. It shows that modal shift is potentially rail’s greatest decarbonisation contribution.

Predicted developments in battery and hydrogen technology are also examined. The report shows why such advances are unlikely to change the scale of electrification required.

Professor Felix Schmid, Chair of the IMechE’s Railway Division, agreed to produce a foreword for the report which stated that he was certain that the report “represents fairly the view of engineers throughout the industry”. Industry support for the report was also shown by its adoption by the Railway Industry

Rail Engineer | Issue 190 | May-Jun 2021

Association. The report complements RIA’s Electrification Cost Challenge Report.

The document took about four months to produce, including comprehensive referencing and rigorous verification of its contents to ensure credibility. Shirres hopes that if decision-makers read and understand its contents, it will make a difference.

The report is available at www.riagb.org.uk/ whyelectrification

NOTICES

VLR gets rapid charge The world’s first Very Light Rail (VLR) ultra-rapid battery charging station has been installed at a dedicated testing centre in Dudley. The milestone brings closer a new mode of public transport, supporting efforts towards decarbonisation.

The charging station will top up battery-powered VLR vehicles wirelessly and autonomously at scheduled three-minute stops, as a lowcost alternative to traditional overhead line electrification.

Developed by Furrer+Frey, the All-In-One OpBrid charger is already in use by electric buses in Spain and the Netherlands, but software created by the Swiss firm’s British arm means the charger can now support new lightweight trams as well.

Furrer+Frey intends to manufacture the charging stations in the UK. The equipment is built with steel from Newport and uses software designed at its headquarters in Derby.

Noel Dolphin, UK Managing Director, Furrer+Frey, said “We are delighted to be building on our long history of rail

electrification with this worldfirst charging solution for Very Light Rail. With the right set-up, the unit will work across buses, bin lorries or even heavy rail, helping us to tackle the climate emergency.”

The charging station is part of a multi-million-pound project to develop a Very Light Rail system for Coventry, bringing the benefits of a tram at a fraction of the cost. A prototype vehicle has already been developed and it will shortly undergo testing using the charger and tracks at the Very Light Rail National Innovation Centre (VLRNIC) in Dudley.

The VLRNIC is a unique facility that, alongside ongoing research into VLR technologies, will help to build a supply chain for integrated VLR systems, creating manufacturing jobs in the Black Country and West Midlands, as well as a VLR market both in the UK and overseas.

Balvinder Heran, Deputy Chief Executive of Dudley Council, insisted the local authority is “keen to promote the use of cutting-edge technology to drive innovation

across the borough. The VLR project is one example of new technological innovations we are proud to develop and be at the forefront. We will be the first area in the UK to trial this ultra-rapid charge station.”

Coventry City Council believes the initiatives will help to significantly reduce the cost of building a light rail line.

The Wednesbury-Brierley Hill route on Birmingham Midland Metro cost £40.9M/km, whereas Coventry’s VLR system is expected to come in at around £10M/km. The Council hopes to have the first services running by 2025.

Rail Engineer | Issue 190 | May-Jun 2021

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NOTICES

Tunnel begins new transport role

ALL PHOTOS: FORGOTTEN RELICS

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A disused railway tunnel near Chepstow has been brought back into use as part of a new active travel route connecting the town with Tintern, five miles to the north.

The Wye Valley Greenway was constructed largely by volunteers, working under the direction of Greenways and Cycleroutes, a charity that develops paths for walking and cycling, mostly in the south-west. It was founded

by John Grimshaw who has designed and engineered many traffic-free routes, starting with the Bristol & Bath Railway Path in 1979 - the foundation stone of the country’s National Cycle Network.

Tidenham Tunnel extends for 1,188 yards beneath Offa’s Dyke, penetrating a limestone ridge on the east side of the river. It was driven with the aid of rock drilling machines on a falling gradient to the north of 1:100. The geology was extremely stable and most of the tunnel was constructed without a lining, although lengthy sections were subsequently added to prevent loose rock falling onto the line. When it opened on 1st November 1876, the structure comprised two parts, with a short cutting separating the main tunnel from a much shorter one at the south end, but this gap was later arched over and infilled.

Rail Engineer | Issue 190 | May-Jun 2021

Work on the greenway started in 2019 when contractors removed the rusting track from the tunnel; it had remained untouched since the railway’s closure in the 1980s. Tarmac was laid in August 2020, but fitting out the tunnel was undertaken by 91 volunteers who attended an autumn workcamp, putting in 235 working days of free effort. Over the course of a week, they installed 132 lighting units and fettled sections of lining in need of attention. A shield was also fitted below the tunnel’s only ventilation shaft.

Kerbs have since been placed to steer visitors away from the rocky edges and distance markers fixed to the sidewalls.

To encourage bat use, lighting levels are kept to a minimum and voids behind the brickwork have been filled to stop draughts. Bat boxes have also been provided and seven recesses bricked up. All these measures were agreed with Natural England and are intended to create the best possible environment for hibernation. The tunnel will close over the winter.

North of the tunnel, the Wye Valley Greenway cuts through a spectacular landscape above the river and is expected to draw tourists to the area, boosting the local economy.

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FEATURE

PHOTO: HS2 LTD/GRIMSHAW ARCHITECTS

Colne Valley Viaduct

HS2’s LARGEST BRIDGE

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S2 is a massive undertaking with many huge contracts already let and underway. The largest bridge will be the Colne Valley Viaduct (CVV) - the most significant visible engineering feature on the Phase 1 route.

It will carry trains at 320kph (200mph) on slab track, extending for 3.37km and weighing 116,000 tonnes. To put that length in perspective, it is equivalent to the wellknown viaducts at Glenfinnan, Ribblehead, Harringworth

The layout and accesses to the site at Denham, Buckinghamshire.

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MOORHALL RD

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DWSC COMPOUND

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CVV will be within the Colne Valley Regional Park to the north-west of London which includes parkland, farmland and woodland, and large reservoirs which surround the River Colne and the Grand Union Canal.

Broadwater Lake - a nationally

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DEWS LANE COMPOUND

MOORHALL RD COMPOUND

NORTH EMBANKMENT COMPOUND

HAUL ROAD ON LAND

BOB WRIGHT

their wide experience to the delivery of this demanding contract.

The site brings challenges of construction access, environmental and public sensitivity, and these have been addressed by the development of an elegant structure and through innovative construction methods for temporary and permanent works. Align’s Project Director, Daniel Altier, said: “I have no doubt that the viaduct will become one, if not the most striking element of HS2 Phase 1 once complete.

The way it will be constructed is going to be equally fascinating for engineers young and old.”

HAUL ROAD ON JETTY

Designing the structure A412

MOORFIELD RD

and Barmouth, and the Royal Border bridge, placed end to end. Built in concrete, the structure will have 57 spans of 45m, 60m and 80m in length.

At a height of around 10m, it will follow an alignment with a horizontal radius of 5,280m - initially a right-hand, transitioning to a left- hand curve.

important site - supports huge numbers of water birds.

This is one element of the 21.6km Contract C1 (Central 1) - awarded to the Align JV in 2017 - that also includes the 16.04km Chiltern Tunnel, north of the viaduct. The joint venture comprises Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick who bring

The High Speed Rail (LondonWest Midlands) Bill recognised that the design of the Colne Valley Viaduct should reflect its national significance. The Transport Select Committee said that “Having argued against a viaduct, local people deserve that its design be respectful and respectable, sympathetically and imaginatively designed.”

A specimen design was produced for HS2 by independent specialists Knight

The concept is for 'rhythmic sequence of low, slender arcs that skim lightly over the surface'.

Rail Engineer | Issue 190 | May-Jun 2021

FEATURE

PHOTO: HS2 LTD/GRIMSHAW ARCHITECTS

Architects, working with Atkins, in consultation with the Colne Valley Regional Park Panel, as well as members of the independent HS2 Design Panel. This formed the basis of tenders for Contract C1 and reflected the key principles of the HS2 Design Vision, together with guidance of the HS2 Open Route Structures Design Approach, Landscape Design

Approach and Bridge Design Requirements. It outlined the design approach behind the viaduct and how it addressed the three core values of the HS2 Design Vision. In particular, it was fundamental that the viaduct should ‘tread lightly’ across this sensitive landscape.

The CVV will be seen by passengers on the Chiltern line, visitors to the park and

from boats on the canal and reservoirs. Each will have different viewpoints and opportunities to see the structure. The design of elements reflects these contrasting views; those that face the pedestrian environment will be of a quality, scale and texture appropriate to the up-close and low-speed scrutiny it will be subject to.

The span over the Grand Union Canal.

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FEATURE ALL PHOTOS: ALIGN

The precast and construction timeline.

The noise of passing trains could impact on wildlife, visitors and boaters so a noise barrier will be incorporated to reduce the spread of noise. The OLE structures will be bespoke to the CVV: as slender as possible and spaced to align with the viaduct’s substructure.

HS2 and Align have worked closely with Affinity Water and the Environment Agency to monitor water quality and agree working methods that will protect wildlife and potable water extraction during both temporary and permanent works.

Align JV are responsible for developing the final design and construction. The all-important architectural design was carried out by an integrated design team - known as Align-D (Align, Jacobs and Ingérop), working with Grimshaw Architects - and developed a structure that is expressive of power, speed and function.

Structural spans and pier forms vary along the length reflecting the changing landscape of the Colne Valley.

Where the viaduct crosses lakes, the 80m spans between V-piers form a rhythmic sequence of low, slender arcs that skim lightly over the surface, preserving landscape views across the water.

Elsewhere, through woodland, the spans are shorter and the piers more conventional. Using facetted concrete forms will add visual patterns and tactile interest to the CVV structure.

Barriers to each side will contain track and wheel noise, and comprise 1.65m noiseabsorbing panels, 2m high selfcleaning acrylic panels to give vision at train window level, topped by a further 0.35m panel.

Rail braking loads could be significant. To resist these, four shock-absorbing units will be included along the length of the deck structure. In addition, there will be four expansion joints.

Rail Engineer | Issue 190 | May-Jun 2021

Enabling works The enabling works for constructing Contract C1 are vast in extent and scope, and delivered by HS2’s enabling works contractor, Fusion JV, and

by Align JV themselves.

A 160ha compound has been established between the north end of CVV and the Chiltern Tunnel portal. This accommodates the precast factories for CVV and the tunnel segments, as well as the offices, plant and welfare facilities.

It will also include space for storing and treating the three million cubic metres of chalk slurry discharged by the TBM. This will eventually be used to form 90ha of new calcareous grasslands across the site.

Site investigation, landowner and stakeholder engagement have been ongoing for 3½ years and agreements are in place with each. Water main diversions have been carried out by Affinity Water to accommodate temporary and permanent works. A 275kVA overhead power line has been realigned and a strategic gas main has been protected from construction works loading by encasing it within a buried bridge structure and other gas mains diverted. In addition, Align have also diverted other water and HV services.

Impacts on ecology have been a key feature of the design and planning, with much of the site being within a Site of Special Scientific Interest. Badger and bat relocation has taken place and containment of invasive species will be a constant feature of construction.

Access along the contract has been designed to minimise highway traffic and a haul route is being constructed throughout; it will be complete

by October. Included are two access points/highway crossings of the A142 near Denham Water Ski Club and at Moorhall Road, with a further site access through the former Hillingdon Outdoor Activities Centre in Dews Lane. The former is a

PHOTO: HS2 LTD/GRIMSHAW ARCHITECTS

FEATURE

busy route and is a regular diversionary route when the adjacent M25 is closed. Site accesses have been created at crossings, with the highway widened and strengthened and traffic control installed.

Load testing of test piles provided Align-D’s structural designers with important information on the ground conditions, resulting in a 1015% reduction in the depth of the piles, with associated time and cost savings.

On-site precasting of deck units

A cross section showing the structural members, acoustic screening and bespoke OLE masts.

Constructing the viaduct The haul roads will follow the bridge alignment on land.

To access the piers within the water and wetlands, temporary jetties are being built. Work got underway in May. These will be of steel construction, 12m in span, with four longitudinal beams carried by piers of driven steel tubular piles.

The working arrangement and design of the jetty have been agreed with Natural England to ensure the integrity of water and wildlife. Decking of the jetties will be concrete

The span over the River Colne.

PHOTO: HS2 LTD/GRIMSHAW ARCHITECTS

The main deck of the viaduct will be precast in sections at a temporary factory in the compound before being assembled from north to south.

The factory is within a steel shed covering an area of 40m x 105m; it is 24.75m in height - 26.75m at

its highest point - a function of the need for the travelling cranes to lift precast units out and over from their formwork.

The factory is being operated

by Align JV, although some specialist subcontractors are being engaged in addition. At present it is dedicated to this contract alone, but other HS2 applications may be identified for it.

Beginning in October and continuing until June 2024, the factory will produce 908 deck units and 92 pier head units. Each one is unique, with constant top cross-section but variable height of 3.5m to 6.7m.

Weights will vary from 60t to 140t each. Units will be matchcast against its neighbour to ensure a close tolerance fit during installation and posttensioning. Steel formwork will

be adapted in height between pours. The external forms will be fixed in frames at 1.5m above the floor, with internal forms being inserted after the placement of the prefabricated steel reinforcement. The design of the formwork is built on the European experience of Bouygues Travaux Publics.

There will be three casting bays, two for the deck units and one for the pier head units.

Two deck units will be cast in each 24-hour period, with accelerated curing to ensure a minimum of 14Mpa. Being more complex, the pier head units will be produced at one every three days. After 28 days, when fully cured, each unit will be transferred to the launching gantry using multi-axle vehicles.

Rail Engineer | Issue 190 | May-Jun 2021

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FEATURE PHOTO: HS2 LTD/GRIMSHAW ARCHITECTS

The northern abutment.

PHOTO: HS2 LTD/GRIMSHAW ARCHITECTS

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planking with sealed joints and a cross-fall to a drainage system incorporating onshore silt traps and oil interceptors. Booms will be placed in the water for emergency spill containment and extensive spill kits will be available on the jetty and in safety boats. All plant will, as far as possible, use biodegradable oils to minimise pollution risks and potential impacts on the ecosystem.

At pier locations, the jetty will be widened to include the whole working area, with decking sections removed as required for permanent piling and to construct cofferdams.

292 bored cast-in-place piles will be required to support the piers and abutments. These will be up to 55m in depth, with a diameter of 1.5m to 1.8m.

The land piers will be constructed conventionally with the facetted formwork erected above bored piles. The water piers are more complex in shape and access. Pile caps will be cast within temporary sheet-

Rail Engineer | Issue 190 | May-Jun 2021

piled cofferdams. On these will be formed a pile base structure followed by the complex V-shaped piers. Soffit formwork will be constructed and, after steel fixing, upper formwork will be added before concrete is pumped to create the structure.

V-pier formwork The spans will be erected between mid-2022 and summer 2024. Each will take 11 days to complete. The 150m long, 690t launching gantry will be launched to the first pier and will then place sections sequentially either side of the pier to maintain balance. Propping will also be installed alongside the pier, beneath the extending deck. The deck sections will be secured to the pier head by internal post-tensioned tendons in the top leaf of the units, followed by tendons in the lower leaf. Once complete the whole bridge will be further externally post-tensioned by tendons within the closed internal box of the deck structure.

Construction timetable This is a very large project and the construction timescale reflects this: » Spring-Summer 2021 construct internal haul road » Autumn 2021 - viaduct segment factory commissioned and viaduct launching girder assembly » Spring 2022 - viaduct deck construction begins from north embankment » Spring-Summer 2024 viaduct deck construction completed » Spring 2025 - Align JV demobilises and HS2 begins railway systems installations.

This bridge project is considerable in both scale and duration. It will undoubtedly become one of the iconic features of the HS2 route, both during construction and in service. Rail Engineer will follow its progress with interest and return to report as the structure begins to extend southwards.

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EARTHWORKS, GEOTECHNICS & CONCRETE

DAVID SHIRRES

Carmont LEARNING FROM

A

lthough the Rail Accident Investigation Branch (RAIB) has yet to produce its final report on the fatal train crash at Carmont on 12 August 2020, there are now clear lessons about earthworks and weather management from this tragic event.

Earthworks safety metrics by control period up to March 2018.

Network Rail’s earthworks assets comprise 70,000 soil cuttings, 20,000 rock cuttings and 100,000 embankments. Most are over 150 years old and were built when there was little understanding of the science of soil mechanics.

As a result, cuttings were overly steep, embankments uncompacted and drainage inadequate. Furthermore, earthworks are more vulnerable to changing weather patterns, resulting in longer periods of prolonged, intense rainfall and hotter, drier summers.

Since 2004, there has been an average of 100 earthworks failures per year; yet, in CP6 - up to 30 November 2020 - the annual average was 222. Nevertheless, there has been a significant reduction in high-consequence earthworks failures and derailments since

Control Period

Date range

Earthwork Temp Speed Restrictions (% of all TSRs)

All earthwork failures

Potentially high consequence earthwork failures

Earthwork attributable derailments

CP1

94/95-98/99

No data

No data

No data

7

CP2

99/00-03/04

273 (7.3%)

No data

No data

8

CP3

04/05-08/09

135 (3.8%)

477

41

8

09/10-13/14

441 (4.8%)

528

32

8

14/15-17/18

290 (3.4%)

381

18

2

Reducing

Reducing

CP4 CP5*

only 4 yrs of data

CP6

19/20-23/24 Trend

Relatively stable Relatively stable

Rail Engineer | Issue 190 | May-Jun 2021

2004. Unfortunately, the single CP6 earthworks derailment was last year’s fatal Carmont accident.

This reduction follows increasing earthworks expenditure which, in 2010, included work to stabilise the steep Carmont cutting and install a crest drain immediately adjacent to the derailment site, as reported in Rail Engineer (Issue 77, March 2011). This explained how, partly due to an increase in the area of farmland and reduced effectiveness of the field drains, drainage run-off from the fields above had overtopped and was destabilising the cutting.

Interim reports On 1 September 2020, Network Rail published its interim report on the Carmont derailment which explained the company’s procedures for earthworks management. It noted that, although £1.3 billion is being spent on earthworks in CP6, it is not practicable to rebuild thousands of miles of earthworks to modern standards, so failures are still to be expected. It also detailed immediate actions taken to mitigate this risk including additional precautions for managing earthworks and operating trains during severe weather.

The report also specified the remits for two task forces led by independent experts.

One, under Lord Robert Mair, reviewed the management of earthworks whilst another,

EARTHWORKS, GEOTECHNICS & CONCRETE

GENTLY-SLOPING CREST DRAIN

STEEPLY-SLOPING CREST DRAIN

OPEN DITCH

PHOTO: PRESS ASSOCIATION

WASHED-OUT DEBRIS

BRIDGE OVER CARRON WATER

PHOTO: RAIB

led by Dame Julia Slingo, considered weather forecasting.

Published in March, these reports aimed to ensure that Network Rail has the expertise, technology and systems to better manage earthworks, and make the best use of weather data.

RAIB’s interim report, published on 19 April 2021, highlighted the sad irony of the derailment being caused by a failed crest drain, installed to protect the cutting. The train had collided with stones washed onto the track from this steeply-sloping gravelfilled drain into which the local topography had directed large amounts of water after 51mm of rain had fallen in three hours, 75% of the area’s average monthly rainfall.

The RAIB investigation had found that the missing gravel had exposed a buried drain pipe for 8 metres upslope of a catchpit where the drain was under a steep gorsecovered slope. RAIB found that this part of the drain was not in Network Rail’s drain

EXPOSED PLASTIC DRAIN PIPE

maintenance database and was unable to find evidence of it being inspected between its construction and the accident.

RAIB’s ongoing investigation will consider the design and construction of the failed drain.

It will also look at the response to severe weather events, decision-making at times of widespread disruption and the mitigation of derailments at such high-risk locations.

Drainage deficiencies The lack of an asset database record for a drain installed less than ten years ago underscores the conclusion in Lord Mair’s report that drainage is generally regarded by Network Rail as a ‘child’ asset which supports the performance of earthworks and track. As a result, Network Rail has a dated drainage system about which it has little knowledge.

Although his report commends Network Rail for its substantial effort in developing a comprehensive earthworks asset management system, it notes that the Earthworks Technical Strategy does not consider drainage or vegetation management in a meaningful way and that, hence, there are key omissions in the earthworks policy, for example drainage competence.

It notes that earthworks stability is dependent on drainage systems that were

(Above) The route of the failed drain at Carmont.

(Inset) An exposed section of drain pipe.

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Work to stabilise Carmont cutting was carried out in 2010.

installed to default designs that took no account of run-off and water flow. Furthermore, there has been little enhancement of drainage, with replacement over the years being like-for-like.

Rail Engineer’s 2011 feature on the Carmont cutting works shows there was an awareness of the increased run-off from the fields above. Yet the way this run-off overwhelmed the failed drain highlights the importance of drainage having sufficient hydraulic capacity.

The report calls for drainage maintenance and cleaning to be undertaken by dedicated teams with sufficient competent staff, as is the case for earthworks examinations. It considers drainage maintenance to be under-resourced as the off-track teams who do it are often overloaded with drainage inspections or diverted away to respond to incidents.

Reviewing earthworks management

A train derailed due to a landslip at Loch Eilt in January 2018.

Drainage was just one aspect of Lord Mair’s 543-page report which also considered earthworks vulnerability, as well as earthworks, drainage and vegetation asset management, and monitoring technologies. It reviewed the historic nature of earthworks assets and provided an academic treatise of their soil mechanics and failure

Rail Engineer | Issue 190 | May-Jun 2021

mechanisms. In considering changing weather patterns, the report noted the very strong correlation between earthworks failures and rainfall over the past two decades.

Lord Mair concluded that the dominant reason for continuing failures is the exposure of over-steep and previously failed slopes to rainfall patterns not previously experienced. His report expressed reservations about Network Rail’s use of soil moisture index to monitor earthworks instead of the more important parameter of pore water pressure.

The threats from climate change were considered to be: » longer periods of prolonged rainfall in winter months leading to rising groundwater levels and higher slope pore pressures » more frequent periods of more intense rainfall triggering washouts and debris flows » hotter, drier summers increasing the amplitude of cyclic slope pore pressure changes, particularly clay embankments » increased demand on drainage capacity and the risk of it being overwhelmed.

EARTHWORKS, GEOTECHNICS & CONCRETE

Asset management The report commends Network Rail for its substantial work in developing a comprehensive earthworks asset management system. It notes that, unlike track or rolling stock assets, earthworks are inherently variable and that this is further affected by uncertain environmental conditions. Furthermore, the earthworks failures trend has significantly worsened since the start of CP6. The 251 failures in the first year of this control period is about double the number in each of the previous three five-year control periods.

5 Earthworks asset criticality band

The report considered that “predicting exactly where failures will occur is like looking for a needle in a haystack” and noted that a more practical approach is to “search for the haystacks”, i.e. vulnerable lengths of slope. It noted that a localised failure strongly indicates that the remainder of the similar slope is vulnerable to future failures.

It also considered how vegetation can have both a beneficial effect - reducing surface erosion, providing root reinforcement, avoiding channelling of flows, maintaining surface pore water suctions - and a detrimental one with blocked ditches and pipes, leaf fall, tree fall and desiccation by the track. Although Network Rail has done work to improve vegetation management, the report considers a more integrated approach to the management of earthworks, drainage and vegetation is needed.

4 3 2 1

E A

A

H R T

W

O

B

R K

S

S A

T Y F E

C

S K R I

D

E

Earthworks hazard category

Recommended changes in examination regime include extending the season to include April and undertaking examinations during or shortly after heavy rainfall. The use of drones and helicopters is recommended both for this and identifying any changes that could adversely affect earthwork stability between routine examinations.

The report considers the effectiveness of the Earthworks Hazard Category (EHC). It notes that 59% of the 2019/20 earthwork failures were classified in lowest risk ‘A to C’ pre-failure categories. Furthermore, around two-thirds of the failures in the early part of CP6 were at sites where no work was planned during the control period. This suggests that many vulnerable earthworks are not included in the investment plan. Hence, it recommends a review of the EHC process.

Earthworks Safety Risk Matrix formed from asset condition and consequence data.

www.geobrugg.com/slope

ool ng t m i n o o i ens gg.c dim obru Free .myge www

Structural Precast for Railways TECCO® System made of high-tensile steel wire

SUSTAINABLE SLOPE PROTECTION

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Rail Engineer | Issue 190 | May-Jun 2021

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LANDSLIP KEITH-HUNTLEY

HEAVY SNOWFALL

GALASHIELS-GOREBRIDGE

On 5 December 2020, a Sandpit trial forecast localised weather hazards which resulted in disruption.

The difficulty faced by Network Rail’s geotechnical engineers in making effective asset management decisions on the basis of multiple and disparate data sources is also considered by the report which concluded that an improved earthworks asset management system that uses data from intelligent infrastructure is needed.

Monitoring to mitigate

A retention wall built for double-tracking between Aberdeen and Inverurie.

As it is currently not possible to detect or prevent all earthwork failures, the report considers their mitigation. This needs reliable monitoring to inform Network Rail’s engineers of the condition of the more critical geotechnical assets.

There are two objectives for such monitoring: detection of failures affecting the safety of the line and collecting data to predict possible failures.

Techniques used or trialled by Network Rail for rapid and instantaneous detection of failures include distributed acoustic sensing by optical fibres surface-mounted tiltmeters and inclinometers and instrumented flexible barriers for rock and soil slopes.

Rail Engineer | Issue 190 | May-Jun 2021

Those with a slow failure response that are suitable for the collection of condition data include: » distributed acoustic sensing by optical fibres » the promising application of wireless tiltmeter systems » satellite InSAR (Interferometric Synthetic Aperture Radar) which compares radar images over time to detect ground deformation to millimetre accuracy » aerial and land-based LiDAR and photogrammetry which international experience indicates to be promising surveillance technologies for slope and landslide management, and the need for train-mounted LiDAR systems to update the geometry and features of cutting slopes » Electrical Resistivity Tomography (ERT) » Shape Acceleration Arrays (SAA) » the continuation of acoustic sensing as part of Network Rail’s R&D programme in view of its potential to detect instability of soil and rock slopes.

More widespread use of helicopter flights to inspect earthworks was considered necessary, especially in hilly or mountainous terrain and after an extreme weather event. In Scotland, five such flights are made each year, specifically for earthworks inspections.

The identification of potential embankment failure sites by Network Rail’s track geometry data collection and analysis workstream was commended, as was the company’s Intelligent Infrastructure programmes and impressive R&D portfolio of novel earthworks monitoring technologies.

Forecasting chaotic weather Dame Julia Slingo’s report considered how Network Rail could obtain the best possible weather forecasts and make best use of them.

It looked at the latest advances in weather forecasting to show what could be made available to Network Rail and described how forecasts start with a global atmospheric assessment requiring 100 million observations to be processed. Global forecasts are needed as the UK’s weather often has its roots from the other side of the globe. They provide the boundary conditions for finer-scale UK regional forecasts that are then undertaken.

This process takes two hours and is repeated every six hours. It requires 20 quadrillion calculations and generates 10,000GB of data.

Such forecasting is one of the most complex computing applications, involving over a million lines of code and the use of dedicated supercomputers.

Due to the chaotic nature of climate systems, current practice is to produce an ensemble of forecasts to assess the probabilities of a range of

EARTHWORKS, GEOTECHNICS & CONCRETE

Cutting work needed to reinstate double track for the Borders Railway near Stow.

outcomes. These are continually reviewed to provide increasingly narrower spread closer to the time of the forecast.

Kilometre-scale forecasting 1-3 days in advance is now possible due to the recent development of models that accurately represent the landscape and a better understanding of the physics of thunderstorms and convection. Nowcasting is a technique that forecasts the next 1-2 hours using optical flow techniques that extrapolate weather radar images to detect the severe convective storms of the type seen at Carmont.

At the time of the derailment, Network Rail’s weather advice used a 10km weather model that could not capture local extremes. However, since then there has been a rapid development of the company’s weather services.

that, after Carmont, the company acted swiftly to improve preparedness for extreme weather events and their impact on earthworks, with the development of a Convective Alert Tool.

Dame Slingo’s report recommends use of the following weather management framework: » Awareness - possible regional red weather alerts are recognised 4-5 days out » Preparation - route controls assign red weather alerts two days out using of kilometre-scale forecasts and begins to take preparatory action » Response - monitoring and alerting by nowcasting during extreme weather events » Recovery - establish priorities and provide weather forecasts for recovery.

Harnessing forecasts

Implementing this framework requires both competent personnel and effective systems that clearly present relevant data to support effective decision making. The weather task force found that there was a gulf in expertise between those creating weather information and those receiving it. Hence it considered that Network Rail should have a ‘weather academy’ to ensure its staff are well-informed users of weather services. This includes scale and predictability awareness. For example, a 10km scale thunderstorm has an average predictability limit of around three hours whilst a 100km frontal rain system can be forecast two days ahead.

The weather task force concluded that a suitable digital platform to present relevant weather data is needed and that this should use Network Rail’s Geographic Information System to provide this data on the network map to best aid effective decision making.

Using weather data to best manage the risks to the operational railway requires an understanding of how rainfall translates into geohazards and the use of forecasts to take timely operational decisions.

The rail network is particularly susceptible to hazards such as surface flooding, washouts and earthwork slides. The weather report notes that Carmont showed how hourly rainfall intensity may be a critical factor driving earthworks failures.

Before the derailment, Network Rail used Extreme Weather Action Teleconferences to advise routes of forthcoming adverse weather. This was considered to be a static process, with limited capability to adjust alerts in an evolving weather situation.

Action to be taken was in accordance with thresholds which, according to the report, needed a major overhaul to reflect variations in exposure across the network, particularly in respect of rainfall. It noted

Such a prototype system, together with Met Office data, was used in a ‘Sandpit’ trial in December. This correctly predicted localised events and generated positive feedback from those involved. One Route Operations Manager, who was particularly impressed by the detail and granularity provided, was confident that such systems would enable mitigation measures to be applied in the right place and also could see the end of miles of unnecessary blanket speed restrictions.

Reducing the risk Modern standards require a significant amount of earthwork retention when double-tracking a single line or reopening a previously closed railway.

However, as noted in Network Rail’s interim report following the Carmont derailment, rebuilding thousands of miles of earthworks to such standards is not practicable in the short-term, either from a funding or delivery perspective.

Prior to Carmont, the last fatality from an earthworks failure was in 1995. Yet, with various earthworks derailments since then, there was a recognition that this was a significant area of risk. Hence £1.3 billion is to be invested in earthworks and drainage in CP6, nearly double that of CP4.

Furthermore, Network Rail had improved its earthworks management for which it was commended in the task force reports.

Yet Carmont showed that more needed to be done.

The depth and detail of the reports led

by Lord Mair and Dame Slingo reflect the expertise of their members and offer many best-practice solutions. Whilst it is not reasonably practicable to detect or prevent all earthworks failures, the recommendations should significantly reduce the risks involved.

Rail Engineer | Issue 190 | May-Jun 2021

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CUTTING EDGE

monitoring GRAHAME TAYLOR

Mountfield Tunnel, where a collapse happened in 1855.

T

he Tonbridge-Hastings line was built by the South Eastern Railway company in the early 1850s ‘as economically as possible’ using a contractor whose expertise extended to invoicing for more work than was actually done. Added to that, it would be almost another century before Terzaghi and Peck, in 1948, introduced the formal concept of soil mechanics. As a result, such nominal matters as cutting and embankment slope angles were determined by ‘what had worked so far’.

Rail Engineer | Issue 190 | May-Jun 2021

(between Tunbridge Wells and Frant) had but a single ring of bricks, but this omission was discovered before it had a chance to collapse.

However, subsequent expensive repairs to the tunnels did not resolve the underlying problems with the route. Over 150 years later, and after several years of very wet winters all affecting the geology of Kent, the management of the line remains a problem.

Cuttings versus embankments Derek Butcher, Route Asset Manager for Geotechnical (Kent, Sussex and Wessex), and Emmanouil Tsoukalas (Manos), Senior Asset Engineer for Kent, lead Network Rail’s team tasked with the tricky issue of ensuring both the safety of trains and the longterm structural viability of the link between Tonbridge and Hastings, as well as several other routes in the South of England!

They have been working on a method of giving 24/7 protection to trains even though there cannot be the same degree of on-site

PHOTO: DAVID ANSTISS

What had worked so far were cutting slope angles of around 40º. To put this in context, just consider the general cutting slopes in current motorway construction. Depending on the soil of course, modern standards would expect slopes of around 20º.

The end product was a railway with oversteep-sided cuttings and embankments, confined within a tight land boundary and built using some dubious and, at times, shady practices. In the current vernacular, many modern engineers - looking at the contractor, the supervision and the lack of formal soils engineering - might say, “Good luck with that one!”

Such cautionary words were not heard - or maybe not even uttered - and, in 1855, Mountfield Tunnel (between Robertsbridge and Battle) promptly collapsed. This was followed by Wadhurst Tunnel (between Wadhurst and Stonegate) in 1862. Invoices for six-ring linings did not match the four rings that had been installed. Grove Hill Tunnel

EARTHWORKS, GEOTECHNICS & CONCRETE

presence. The human resources would be too great and it would greatly increase the risks to people having them continuously exposed to moving traffic.

Their attention is primarily on cuttings because there is a fundamental difference between the way cutting slopes and embankments fail.

Embankments can fail catastrophically, but like many structures - they do have the common decency of giving an element of warning.

Small movements in track geometry can be seen by track patrollers, can be detected by track recording trains and can be felt by train crew and passengers long before any failure develops. However, rectifying an embankment failure - with track suspended in mid-air - may take months.

On the other hand, movements in cutting slopes are difficult to detect by sight and are not detectable by recording trains or train crew.

The failures in themselves may be minor, with just a few tonnes of soil detaching from the cutting slopes. Remedial work may take just a few hours, but if the spoil reaches the track and is undetected then there is a significant risk of a train colliding with the rubble at speed and a subsequent derailment.

Historic monitoring Historically, incipient cutting failures have been recognised and monitored. The process was crude, expensive, but effective. The simplest regime was to drive pegs into the slope and measure distances between them. Any failure would manifest itself by disturbing the existing measurements. The weakness lay in the ability of those on site being able to take accurate readings in all weathers, compounded by the availability of the staff required.

Manual monitoring of a slope would be done weekly or every day, up to twice a day. Only if something was actively failing would a slope be monitored more frequently. With a route as susceptible to severe weather and with many vulnerable sites, these sorts of regimes become untenable.

Funding Nationally there is funding from the Government to proactively intervene in cuttings which pose the greatest safety risk.

Derek reacted, “We rolled out quite a massive programme in terms of budget and scale in CP6, and real credit is due to our directors who allocated funding of about £3 million in Kent and £3 million in Sussex.

“What is really satisfying is that we’re introducing new technology. We’re one of the first routes to experiment with drones to capture information from above to create images or 3D models. The central team has put a good focus in using LIDAR information (Laser Imaging Detection And Ranging).

“In 2014, we had a helicopter pass and another in 2020 to compare how much detail had changed in the models created.”

A landslip occurred in the approach cutting to Wadhurst Tunnel.

Remote monitoring In the years before Manos joined Network Rail, he had worked with a monitoring contractor, checking the behaviour of buildings around the site of the Victoria Station expansion. He was thus familiar with the installation and use of networked tiltmeters.

Manos explained, “It seemed logical to me that the same technology could be used to provide an almost real-time picture of the state of the worst cutting slopes on the route. In 2018, we acquired 20 tiltmeter units and the results were very promising.”

As it says on the tin, these devices measure the changes in tilt of a unit in three dimensions when fixed to a peg driven to a known depth into a cutting slope. If the slope moves, then the tiltmeter registers a change and, with a bit of smart calculation, it is possible to deduce how far and in what direction the slope itself has moved.

Each unit has a battery that powers a small processor that sends out a signal wirelessly to adjacent tiltmeter units and to a master PC

Rail Engineer | Issue 190 | May-Jun 2021

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EARTHWORKS, GEOTECHNICS & CONCRETE (Right) Remedial works have also been required in a cutting at High Brooms.

that collates all the gathered information. The overall picture of the units, which are arranged in rows on the slope, is logged and compared with a set of rules laid down at the initial design stages of the monitoring scheme.

If the monitoring PC detects a movement in a sensor, it first checks whether the movement is logical or whether it could have a spurious cause - animals, a falling branch or even human clumsiness. If a subsequent measurement shows that the reading is real, then the site is photographed by one of several cameras positioned to give a view of any problem. If it persists, then an alert email and text is sent to an engineer for assessment. In the early experimental days, these messages were sent direct to either Derek or Manos, but it became obvious that issues such as holidays, other work and sleep could get in the way.

Train alerts Conversations were held with Control - the 24/7 organisation that deals with all train running - so that alerts could be processed through a team of ‘flight engineers’. These engineers look at the alert data and images, interpret what is going on and decide whether it is necessary to stop traffic until

there is an on-site assessment.

Being within the Control organisation gives a direct link to train movements.

This process proved its worth at Wadhurst Tunnel, site of the 1862 failure. There were serious potential slope incursions around the tunnel portal. The system flagged up movement and trains were stopped in time before the track was obstructed.

PHOTO: SENCEIVE

PHOTO: SENCEIVE

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Senceive staff carry out tilt node installation works on a cutting slope.

Rail Engineer | Issue 190 | May-Jun 2021

EARTHWORKS, GEOTECHNICS & CONCRETE

Kwik - Step Modular Platforms and Stairways

Lightweight FRP Minimal Groundwork Simple Assembly Available from Stock The grid system of detectors works best in granular and clay slopes. It cannot be used in the same way on rock cuttings as it is not possible to drive in the pegs! However, it is possible to detect any impact on a barrier fence at the base of a rock slope that gets struck by debris.

Platforms & Walkways

The project gathers pace From the early beginnings with just 20 tiltmeters, the team now has control of 5,100 units - supplied by Senceive - installed on 70 sites around their patch. The term ‘real-time’ was qualified earlier because there is always a time lag between one measurement and the next. This is currently set at five minutes - a balance between the realistic likelihood of a movement with the need to avoid too much data and to prolong the battery life which, for the tiltmeters, can be two years or more. But a unit continuously trying to register on its local network can consume more power. Logging frequency is increased if the system detects movement.

The coordinating PC and the cameras are powered by solar panels.

Technology is advancing very quickly. At the moment, efforts are concentrated on those sites of greatest risk. Equipment still needs attendance for inspection and maintenance; it is not completely autonomous.

However, it is not beyond all possibilities that real-time visualisation of all at-risk slopes could take place from one bank of screens.

Minimal Groundwork Simple Assembly Use Immediately Range from 12° to 45° Available from Stock

Galvanized Steel Stairways

The common platform As often happens with a rapidly expanding project, there can be many differing forms of information from a variety of differing systems. At the moment these are widely varied, with little in the way of a common platform.

It is an aspiration - at present being explored with SixSense - to bring as many legacy systems together in a single format to streamline the effective management of these 150+ year old assets, with their dubious historic build quality.

“Good luck with that one too!”

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0117 929 1400

Rail Engineer | Issue 190 | May-Jun 2021

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The

slippery slope

A

lthough RAIB’s final report into last year’s tragic derailment at Stonehaven is still awaited, we know now that a significant contributing factor was heavy rainfall washing material onto the track. The accident resulted in the first earthwork-related fatality since the death of a guard at Ais Gill on the SettleCarlisle line in January 1995.

Rail Engineer recently met up with the first fulltime earthworks asset steward, Gerry Manley, to learn about the early proactive management systems and how Network Rail has improved the stewardship of earthworks.

History lesson When the rail network was built in the 1800s, thousands of embankments and cuttings were constructed and Network Rail now has to manage over 190,000 earthwork assets. The network was built rapidly and, in places, poorly - without the knowledge of soil mechanics and geotechnical engineering that exists today.

If you look at most railways constructed by the Victorians, you will note that the cutting and embankment slopes are far steeper than those of a modern road or railway and do not offer the same resilience to failure. A report

Gerry Manley

Rail Engineer | Issue 190 | May-Jun 2021

by Thomas Telford as long ago as 1829 said that many railway embankments were largely formed by the end-tipping of material down the formation. This was a process Telford specifically disapproved of as it would “delay consolidation and increase the tendency for slipping”.

Nearly 200 years later, geotechnic earthwork engineers are in place on all regions and the asset management process has much improved.

EARTHWORKS, GEOTECHNICS & CONCRETE

The price of failure Following rail privatisation in 1994, a small group of asset engineers was formed in each Railtrack region to act as asset owner and steward. Their role was to monitor asset performance and specify interventions on a risk basis, as well as auditing the maintenance contractors. These engineers were organised on a discipline basis for track, signalling, electrification and plant, telecoms, structures and buildings. However, there was no dedicated asset steward for earthworks and with only a small HQ support resource for geotechnics.

It generally fell to the regional track engineers to look after earthworks, but they were not resourced to do so proactively; many did not have the required knowledge or experience.

They had enough to do with keeping track geometry compliant so there was no, or very little, proactive management of earthworks.

At Ais Gill, a Carlisle-bound Sprinter was derailed by a landslide and was run into by another Sprinter travelling south. Four years later, a similar incident occurred a few miles south at Crosby Garrett, north of Kirkby Stephen, where 100 tonnes of material caused a Carlisle-bound Sprinter to derail. A southbound coal train weighing 1,392 tonnes then hit the Sprinter; fortunately, nobody was seriously hurt this time.

In January 1999, Rail magazine’s headline read “Is the S&C safe?” and reported on other landslips and incidents that had occurred on the route. It was suggested the S&C should not stand for ‘Settle and Carlisle’, but for ‘Slippage and Collision’.

The Crosby Garret failure was attributed to a crest drain that had become blocked over the years, along with a nearby spring with water

collecting in a ground concentration feature outside the railway boundary. Generally, the asset inspection regime did not adequately look at crest drainage, nor beyond the fence.

Something had to be done as the earthwork risks and failures were not just on the S&C. So Gerry Manley was appointed as a fulltime geotechnic asset steward engineer in Manchester to establish and lead a robust proactive earthwork asset management regime for the region.

Scoping exercise Gerry was an experienced railway Charted geotechnical engineer with a civil engineering degree and a Masters in geotechnics. He had been involved in earthwork design in BR days in York, working in the Soil Mechanics department.

Back then, most of the earthwork activity around the network was reactive - once failures had occurred - or on new formations for limited railway enhancements. Gerry had also taken part in the Ais Gill inquiry, so he knew of some of the issues on the S&C route.

As the first earthwork asset steward, his first insight into the challenge ahead was being asked to draft his own job description, as none existed! Another immediate concern was that the entire earthworks budget for the northwest region was only a few hundred thousand pounds. This was exceedingly small considering the number of earthworks. He was also handed a large volume of paperwork detailing concerns which no-one had been able to focus much attention on.

A consultant’s report was available detailing 36 at-risk earthwork locations on the S&C route, so Gerry visited every one to prioritise

PAUL DARLINGTON

Rail Engineer | Issue 190 | May-Jun 2021

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and scope the required interventions. This established 14 locations where major work was required, costing millions of pounds. Until the work was carried out, a mitigation measure was implemented consisting of rain gauges to identify excessive local rainfall. When predetermined thresholds were exceeded, special emergency speed restrictions were put in place.

The system was crude by today’s standards, but it was a step in the right direction.

Good drainage Making a case to investment panels and other asset stewards to release their budget is always a challenge; many hours of stakeholder consultation, negotiation and risk assessment were needed to identify the required budget and gain approval to carry out both minor and major interventions. The objective was to use the available data to identify and fix the root cause of earthwork failures, rather than just treating the symptoms.

Shortcomings in communication are present in nearly all risk management failures and justifying the work undertaken on earthworks required effective dialogue to ensure the leadership team and stakeholders properly understood the risks and their implications.

Following work at the 14 high-risk sites, it only took one minor earthwork failure on another part of the region for the investment panel to question if the money had been spent in the right place. This is a problem asset engineers often face and it requires qualified, professional, responsible leadership to demonstrate the proper management of risk and that a robust ‘stich in time saves nine’ strategy is in place.

It was frequently found that deficiencies in the local drainage system and surface water standing on, or flowing from, adjacent non-railway land increased the risk of failure. Heavy rain was - and is - the most dominant weather event to cause harm to earthworks and, with the extreme weather becoming more frequent, the risks are increasing.

Attention was therefore needed to manage water events occurring in locations where they had not been observed before.

The track inspection regime carried out by maintenance contractors was, in many cases, just that - a track inspection with little visual monitoring of the earthwork slopes and cuttings.

So, cards were produced to assist patrollers in identifying possible earthwork stability issues, along with A3-size posters for staff cabins.

These were very well received during a Railway Inspectorate audit of the region and were recommended as best practice across the network. It is believed that the materials are still in use today, as is the original soil and rock slope hazard index system developed by Gerry.

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EARTHWORKS, GEOTECHNICS & CONCRETE

Good communication with other asset engineers was required so that, for example, signal and telecoms engineers did not remove the toe of cuttings to install cable routes or equipment without proper consideration of the earthwork asset.

Network Rail can manage activities within their boundary, but that is not always the case for activities undertaken by third parties and neighbours. A farmer who previously ploughed his field parallel to the railway may change to ploughing perpendicular to it; this can increase the amount of surface water flowing towards the line.

There was also a situation where a housing developer removed the bottom of a 14m high viaduct approach embankment to extend the size of the gardens on offer. Gerry was on site when a couple arrived to inspect their shiny new house, only for them to find it being demolished so urgent stabilisation works could be undertaken!

The developer ultimately had to pay costs to the railway, running into millions of pounds.

New technology Today, competent and experienced railway geotechnical engineers are in place on every route and region. It is an interesting but challenging role. Earthworks condition will always be a risk, no matter what budget and resources are available, and the assets’ ability to perform reliably will need careful management, particularly at times of prolonged rainfall. With the hotter climate which we are already experiencing, rainfall will arrive in more intense storm events.

Prolonged periods of wet weather increase water pooling and pressure, making an asset failure more likely. The effects of vegetation on soil and rock

slopes can also be dramatic. Drains can get blocked or damaged and, ironically, excessive vegetation removal can also destabilise some delicate earthworks, so it all needs careful management by engineers who know what they are doing.

Every aspect of engineering involves risks which must be understood, prioritised and moderated in order to utilise resources appropriately. The strategy to manage earthworks includes the need to continually develop better technology to make best use of the resource available, reduce cost and steadily evolve more efficient methods for controlling risks. New technology can help - drone inspection and intelligent asset monitoring and reporting to target the interventions required to avoid failure, for example.

Task force As we report elsewhere in this issue, a comprehensive review of Network Rail’s earthworks management, by a task force led by Professor Lord Robert Mair, has recently reported that surface and sub-surface water management is probably the single most important factor in determining if, when and where an earthwork failure will occur, although the task force did acknowledge that the prediction of precise failure locations is almost impossible.

Today Gerry is the director and owner of CIL Geotechnics Ltd, offering design and consultancy services to a wide range of clients in many areas within the railway industry, providing expert witness and independent assessment, along with structural, geotechnical and drainage design and Contractors Engineering Manager, Principal Designer support.

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EARTHWORKS, GEOTECHNICS & CONCRETE

Instrumentation AND monitoring

C

hris Preston has experienced a diverse geospatial career in the rail industry and seen the rise and fall of many significant technologies. The former Professional Head of Topographic Services at Network Rail and most recent past-president of the Chartered Institute of Civil Engineering Surveyors reflects on changes in survey and monitoring methods, looking specifically at the impact of one of the technologies that is very much in the ascendancy - wireless remote condition monitoring.

Back in the Sixties and Seventies, monitoring was a labour-intensive affair, requiring regular site visits by staff. It usually provided relative rather than absolute measurements, often from simple taped offset measurements from a theodolite, or angles and distances to points for tunnels and retaining walls based on conventional optical levelling. Borehole monitoring was often limited to simply lowering a probe to see if the tube had sheared. Issues regarding accuracy and repeatability were common and there was little chance of early warning of instantaneous events such as a landslip or retaining wall failure. Results were derived from manual calculations, with a slow response to stakeholders.

In the Eighties and Nineties, monitoring was still labour-intensive, but the advent of absolute monitoring meant that all the measurements in an area could be based on a single coordinate framework. Computer analysis of the survey network improved accuracy and efficiency, but some relative measurements were still used. The classical surveying triangulation and distance network was replaced by GPS in the Nineties, bringing significant improvements in efficiency.

Angles and distances to individual ground markers were used and digital levels with a bar-coded level staff improved the speed of measurement.

Track monitoring sensors on the Paris Metro.

Rail Engineer | Issue 190 | May-Jun 2021

Although this provided greater accuracy, there were still repeatability issues and little chance of detecting the crucial early signs of a sudden failure. Wider use of computers enabled manual data input into spreadsheets and the response time to stakeholders began to improve.

More data, fewer wires Since the turn of this century, monitoring has really benefited from the use of modern technology. Total stations have become automated and additions to the toolbox include laser scanners, GNSS, precise levels, extensometers, tilt sensors, inclinometers, tell tales, digital callipers and automated cameras.

Weather stations provide environmental monitoring, and noise and vibration can be measured automatically.

Surveying total stations are now able to lock on to individual survey prisms (Automatic Target Recognition) in a defined observation sequence, as well as providing a camera view of the location being observed. This is helpful should a prism be damaged or obstructed.

But most of these systems still need power supplies and extensive cabling, and site visits to collect data from sensors. This is problematic in view of the drive to keep boots off the ballast.

EARTHWORKS, GEOTECHNICS & CONCRETE

It is therefore no surprise that the rail sector has led the way in adopting wireless remote monitoring technologies to detect early signs of asset failure and track gradual changes in geometry. These autonomous systems comprise long-life sensors and wireless communications platforms, often powered by solar panels.

They provide stakeholders with data in near real-time.

Whilst the technology is robust and the measurements highly repeatable, it is often used alongside more orthodox survey instrumentation and manual inspection for validation.

Widespread implementation Many of the high-profile infrastructure projects in the UK have relied on data from wireless remote monitoring and will continue to do so into the future. Examples include the East Coast Main Line capacity improvement project at Werrington and construction of the A14 viaduct over the same line. In both cases, wireless track sensors have informed project teams of movement and changes in geometry associated with the ongoing construction works below and above the railway.

HS2 has commissioned largescale deployment of wireless remote condition monitoring, mostly on existing assets within the zone of influence of ongoing or planned construction activity - one example being the track and structures at Curzon Street in Birmingham.

At the southern end of the route, many hundreds of track sensor nodes are in place on the lines outside Euston Station, gathering baseline data on track geometry. They are set to remain throughout the construction phase.

Comparable deployments are being commissioned at Old Oak Common.

Monitoring systems Wireless monitoring has certainly not replaced optical surveying and the two approaches are often used in tandem. An example was on the Luas light rail system in Dublin during nearby construction.

Total stations known as ‘MultiStations’, a digital level, wireless tilt sensors and Lecia GeoMoS monitoring software were combined to allow non-intrusive movement monitoring. These instruments scanned the dual tramway continuously and hosted live data directly onto a secure webpage for the relevant stakeholders to review. The captured scans consist of thousands of measurement points with x,y,z coordinates.

Three initial scans set a baseline; all subsequent scans were compared to this. The system provided automated alerts notifying designated stakeholders when values exceeded a designated threshold. To provide assurance, physical on-street precise levelling - captured by a digital level - was undertaken weekly.

Automation and Artificial Intelligence As time passes, monitoring systems are becoming smarter and more automated, bringing many of the benefits associated with the internet of things. In contrast to the toolkit of earlier decades, they are not just dumb instruments and can do far more than just take measurements and send them to stakeholders: they can respond to events such as ground movement at one sensor location by triggering the wider sensor network to wake-up and send reports at high frequency - less than a minute - and to transmit images of the site in any light conditions.

In most railway environments, these result in automated alerts being sent to stakeholders. The most sophisticated and robust systems can send alerts directly to route control, triggering a decision-making process that will reduce train speed or even close the line in the event of a significant event such as a landslide blocking the line. In most cases, human intervention such as a site visit is still the first response. Validation and sense checking is a wise precaution to prevent false positives.

Harnessing intelligent monitoring technology to keep people and infrastructure safe

Contact us info@senceive.com www.senceive.com

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Installing cellular cameras and tilt nodes on a cutting slope.

Case studies The value of wireless monitoring was proven in the well documented case at Barnehurst in south-east London in 2019. A Senceive FlatMesh wireless monitoring system comprising tilt sensors and cellular cameras detected the early signs of a landslip and sent alerts of localised gradual movement over the course of two days, during which time trains were allowed to run at reduced speed. When the slope finally gave way and deposited some 300 tonnes of earth and vegetation on the track just a few hours before the morning rush hour, the system sent alerts and images in near-realtime and signals were immediately set to red. Whilst this did not prevent disruption, it significantly reduced the risk of a potentially dangerous derailment.

Following this compelling demonstration of how intelligent monitoring technology can dramatically reduce the dangers and disruption caused by slope failure, Network Rail has adopted the technology on a wider scale on a number of routes. In Kent and Sussex, nearly 6,000 tilt sensor nodes, 222 cameras and 111 wireless communication gateways have been installed to relay data from site to the cellular network.

A nano tiltmeter monitoring deformation of a tunnel.

Rail Engineer | Issue 190 | May-Jun 2021

One of the attractions of wireless monitoring solutions such as the Senceive FlatMesh solution is the speed and simplicity of installation. In the event of a structural or geotechnical failure, a system can be installed in hours, providing engineers with crucial insight regarding ongoing movement.

The value of this type of emergency monitoring was demonstrated on the West Coast Main Line near Rugby in January when heavy rainfall washed out material supporting the tracks.

Data from an emergency monitoring kit helped engineers to keep trains running through the following week while repairs were carried out, therefore reducing the impact of the incident.

What next?

In many situations, wireless remote monitoring is most effective when integrated with other systems and data platforms to deliver a wider range of information and greater confidence in the outcomes. Taking the example of slopes, data acquisition systems could combine wireless tilt sensors and cameras with terrestrial or satellite synthetic aperture radar. Data management and automated decision-making process could integrate their data with highly localised weather forecasting.

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FEATURE

Winning Dawlish's COASTAL BATTLES

W

ork to improve the resilience of the railway infrastructure to climate change is once again in full swing at Dawlish, on the coastal stretch of the Great Western Main Line between Exeter and Newton Abbot.

360 metres of new sea wall was constructed at Dawlish between May 2019 and July 2020.

Following the major breach of the sea wall in February 2014 necessitating a full line closure for eight weeks whilst major emergency restorative works were carried out - the location has not often been out of the news. After a detailed study

by Network Rail to develop a ‘climate resilience’ strategy for the next 100 years, some of the major physical works necessary to fulfil that strategy are now in full progress.

length of new sea wall alongside Dawlish Station and from Coastguards breakwater through to Dawlish Water, the local river’s outfall to the beach.

Stage 2b will see the completion of the sea wall between Stage 1 and Stage 2a, including bridging over Dawlish Water. It also comprises the reconstruction of the Down platform and the provision of passenger lifts and a new footbridge.

A staged approach

Design considerations

Phil Morton, Project Manager for Network Rail showed Rail Engineer the works and explained the overall programme. The first stage (Stage 1) ran from May 2019 to July 2020 and saw the construction of 360 metres of new sea wall in front of the original structure supporting and protecting the railway alongside Marine Parade.

The second stage, actually split into two distinctly different parts (Stage 2a and Stage 2b), is now on site. Stage 2a comprises the construction of a 315-metre

The stretch of sea wall being built in Stage 2a has a superficially similar external appearance and design to that of the wall in Stage 1. However, the internal and foundation arrangements are necessarily different because of the greater depth to solid rock over the extent of the Stage 2a wall.

Evaluation of the condition of the original Brunel masonry wall, with the knowledge of its frequent susceptibility to marine damage and the difficulty in achieving adequate repairs, meant that it was decided to go for the most

Rail Engineer | Issue 190 | May-Jun 2021

MARK PHILLIPS

robust alternative: that is to build a completely new and independent wall in front of the old one. The form that this wall takes is a row of circular hollow section (CHS) piles twisted into the rock, rather than driven, to reduce the impact on the local receptors and achieve the required imbedment. This is followed with a scour-protective concrete footing, then faced with precast reinforced concrete units, capped with recurve units and the void between the old and new wall completely backfilled with lowcarbon mass concrete which was developed and designed

by BAM Nuttall and Hanson.

The wall had to be approved for planning and environmental considerations by the local authority, Teignbridge District Council, and the Marine Management Organisation.

Various options for the height of the wall and profile of the recurve capping were modelled in the laboratory at HR Wallingford to verify the computer-based modelling and ensure that the correct solution is being implemented to give 100 years resilience.

FEATURE The existing sea wall is heavily used by the local community and also forms part of the South West Coast Path. It is a very popular local amenity to walk on - as is the beach below it - and there were always going to be some objections to the original masonry wall being no longer visible. However, the new wall will provide a much wider and safer walkway at a higher level. As a measure to reduce the visual impact of the concrete wall, Reckli Yukon formliner has been used to provide the facing panels with a textured finish.

Consultants for the overall design of Stage 2a are Arup for the development and Tony Gee and Partners for the detailed design. The main contractor also responsible for Stage 1 - is BAM Nuttall, awarded a design and build contract.

Construction environment and sequence Obviously, virtually all the preparation and construction aspects of the new wall are subject to tidal working. The only available time for placing scour protection, casting of the recess to receive the wall units, installation of the wall units and infill grouting is between 4 and 6 hours, depending on the tidal range changes between Spring and Neap tides. Longer working times were possible

for the pile installation thanks to the use of a WaveWalker.

BAM Nuttall has opted to work both low tides in each 24-hour period, whatever their times.

The CHS piles were installed between November 2020 and February 2021 using the WaveWalker jack-up barge, supplied by Fugro and Van Oord in a joint venture. It is believed that, for maintenance on Britain’s railway infrastructure, this was the first use of this impressive piece of equipment, an eight-legged platform capable of vertical height adjustment, lifting and handling piles into position very accurately for installation and which is able to literally ‘walk’ itself to its next operating position.

The Stage 1 section of new sea wall.

The WaveWalker was specifically modified to allow for its intended use by welding a large cantilever bracket onto the outside of the barge to support the 114-tonne piling rig during the installation of the piles. The opportunity was taken, before releasing the WaveWalker from site, to also install some of the piles needed for the Stage 2b part of the scheme.

The piles are 762mm in external diameter and vary from 13-16 metres in length.

Once in place, they are filled with mass concrete and, on the seaward side, are protected from future scour damage by a 1.5-1.8-metre deep mass concrete bench. The casting of this concrete scour protection

A multi-purpose landing craft delivers plant and equipment onto the beach.

PHOTO: BAM NUTTALL

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FEATURE PHOTO: NETWORK RAIL

An eight-legged WaveWalker lifted the piles into position for installation.

requires repeated re-excavation of the beach material between tides to progress the installation.

A suitable concrete mix was developed for this particular operation by Hanson and BAM Nuttall by trialling six different mix designs on Stage 1 of the project, of which only one was suitable for the intended use/ design life of the substructure.

The mix contained a large variety of additives including microsilica, UCSPak and VC20RM which were required to allow BAM Nuttall to place the concrete in a marine/tidal environment.

Wall units in the hightide refuge, awaiting installation.

Rail Engineer | Issue 190 | May-Jun 2021

Following progressive completion of the scour protection, a further structural element is added, again requiring repeated reexposure between tides until completion. This final stage is the shuttering and casting of a concrete trough to retain the bottom of the precast facing wall units.

Manufactured in Ireland by Shay Murtagh, these are 2.0 metres in width and up to 6.5 metres in height, weighing just under 14 tonnes. Fixing of the wall units and the precise adjustment of their position is an ingenious process,

developed by BAM Nuttall and Tony Gee using experience gained during Stage 1.

Each adjacent pair of CHS piles has short channel sections welded horizontally onto the rear side of the exposed portion of the piles - at the midpoint and lower down - to form two walings. Threaded tie bars cast into the wall unit are then used to pull itself in against the walings to adjust its position. At the top of each unit, there are two other cast-in articulated ties. These are laid on an adjustment grillage which is bolted to the top surface of the concrete infill to each of the two piles. This facility enables adjustment of the upper end of the wall unit. So, between the two tie bars and the upper wall ties, the final correct geometry of the wall unit is relatively easily achieved.

Jack Brookes, agent for BAM Nuttall, told Rail Engineer that, on good tides, three wall units can be installed in the time available. The next step is to provide grout to three areas of the wall units. On each tidal working, 3½ tonnes of a special grout are mixed and placed by hand. The bases of the wall units, where they sit in the preformed trough, are grouted in and the vertical space between adjacent wall units is grouted using a woven

FEATURE

geotextile ‘sock’ which expands to close the gap when filled with the rapid-hardening grout.

Also, because there is only a tangential contact between the back surface of the wall units and the CHS piles, grout socks are also placed and filled in these positions in order to give a greater bearing area.

The grout is a special rapidsetting non-shrink specification which achieves compressive strengths in excess of 12MPa after one hour. The early strength gain requirements are needed to support assumptions made with the temporary supporting of the facing panels prior to them being backfilled.

The final stage of the basic wall construction is the infilling between the old masonry wall and the rear of the new wall with mass concrete in maximum lifts of 1.0 metre. This can be done without the need for track possessions. Undertrack crossings have been put in, enabling concrete to be pumped from delivery at the Up-side station yard, and, with a range of 160 metres from the pump being achievable, only two under-track crossings are needed, positioned at the third points along the site.

In total, it is estimated that around 7,000m3 of concrete will be used. In view of this large quantity, BAM Nuttall has worked with Hanson to develop a low-carbon concrete to minimise the environmental impact.

A serious problem with the existing wall has been the fairly frequent overtopping by waves, leading to significant flooding of the railway tracks and line closures. The new design of wall has taken this problem into account as a part of the optioneering of various designs and it is expected that the frequency and severity of overtopping will be reduced by 90%. However, the provision of drainage from the track is still required so piped outfalls are incorporated into the mass concrete infill at 20-metre intervals. Special facing wall units with a castin outlet for the outfall are installed at these positions.

Plant access and materials storage Access to the working area on the beach is severely restricted by the low-headroom railway bridge across Dawlish Water and the pedestrian access to the sea front, so only small plant is brought to the worksite this way. Large plant, excavators and a mobile crane are loaded onto a multipurpose landing craft - the MTS Terramare with its 50-tonne load capacity - at Teignmouth docks and delivered to the beach at Dawlish. To protect the plant when not in use at

high tide, refuges have been put in at each end of the site.

These refuges take the form of a U-shaped layout of steel freight containers fully loaded with beach material, thereby forming effective protection for the plant.

Most materials, apart from the pumped concrete already described, can be brought in under the railway bridge. Even the large precast wall units, which are stored until needed in an off-road compound not far away, can come in this way on trailers and be unloaded into the refuge at the south end of the site ready for installation.

The CHS piles were also brought to site by this route.

Placing a wall unit into position.

Working arrangements BAM Nuttall has around 30 employees here, based at their main site offices at Dawlish Warren. The labour force is comprised of 60-70 staff covering two shifts equally, split between BAM Nuttall and TBT Recruitment Ltd. BAM Nuttall has taken several measures to alleviate some of the features of tidal working

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FEATURE

A section of partially complete wall showing the mass concrete infill.

An aerial overview of the site.

disruptive to the body clock.

Working every tide, i.e. twice per 24-hour period, is slightly offset by giving staff alternate weekends off duty. Also, by moving the start and finish shift times each day to accurately follow the tide times, i.e. advancing by around one hour per day, would maximise the available site time. However, Jack Brookes explained that they have preferred to maintain the same shift times for 4 days consecutively so as to not confuse the circadian rhythm more than necessary.

Furthermore, the Health and Safety Executive’s Fatigue Risk Index is calculated on a regular basis to monitor for

Rail Engineer | Issue 190 | May-Jun 2021

hazards related to disruptive shift working. The objective is to ensure that scores are kept below 40 which is the maximum recommended on the range from 0-100 on the Index criteria.

JP Crane Hire and Lynch are the main plant suppliers whilst Camfaud is the subcontractor for the concrete pumping.

SGC provides safety-critical resources. Also, Network Rail was keen to emphasise the use of local suppliers - particularly of materials - to the tune of somewhere between £5-10 million out of the overall project value of £80 million.

Stage 1 was valued at £25 million, Stage 2a, which will be complete by Autumn 2021, is

another £30 million and Stage 2b, which is out to tender at present, will be carried out between Autumn 2021 and Winter 2022.

They say that walls have ears, but this one only has instalments. Rail Engineer will return to Dawlish next year to review the successful completion of Stage 2a and report on progress with the most complex piece of the jigsaw, Stage 2b. This will link up with the two earlier stages and greatly enhance the station.

Once complete, the project will give this vital railway artery better defence against the sea than ever before in its long history.

PHOTO: BAM NUTTALL

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FEATURE

MALCOLM DOBELL

Piccadilly Line trains: a journey from 1891 to 2025

L

ondon’s first tube railway was the 1891 City & South London line. Trains were hauled by electric locomotives, some of which were built by Siemens Brothers. The tunnels were even smaller than today’s, circa 4m in diameter. The Tube has expanded significantly and now requires more than 540 trains to maintain the service. It is characterised by small tunnels leading to a constant search for ways to make the best use of the limited space.

Rail Engineer | Issue 190 | May-Jun 2021

is still owned by the London Transport Museum and used occasionally on the network.

This configuration was built

PHOTO: BRIAN HARDY COLLECTION

The first tube train for the City & South London Railway in 1891, one of two supplied by Siemens Brothers.

There have been just four generations of tube trains.

The first locomotive-hauled trains were built in the late 19th/early 20th century. Next, motor cars with electrical compartments behind the drivers’ cabs were developed and built until the mid-1930s.

It was in 1935 that the London Passenger Transport Board led the development of prototype trains with all the equipment under the floor, leaving more space for passengers. These had bi-parting doors towards the middle of the cars and single doors at the ends. The prototypes led to the 1938 tube stock, one example of which

in six, seven and eight-car formations for over 70 years, culminating in the 2009 Victoria line stock. So what’s next?

In November 2018, London Underground (LU) placed a contract with Siemens Mobility for a fleet of 94 trains for the Piccadilly Line, with options covering further expansion of the fleet and to replace the Bakerloo, Central and Waterloo & City lines’ trains.

FEATURE

PHOTO: BRIAN HARDY COLLECTION

Nothing more was published until a joint Siemens/London Underground press conference in March 2021.

This article gives some background to LU’s thinking and an outline of Siemens’ design.

1928 tube stock with its electrical compartment behind the driver's cab.

The challenges By 2003, the configuration of the large-profile S-stock had mostly been settled, featuring air conditioning, walk-though wide gangways and all double doors. But how could these features be applied to tubeprofile trains?

In the late 1990s, LU had carried out a study aimed at maximising tube train capacity, christened the Space Train.

Using this work, it started thinking about how S-stock’s features might be incorporated into the next tube stock. One view was ‘specify what you want and industry will deliver’, but it is not that simple due

to the small size; these are bespoke products presenting many challenges.

Double doors: the space available is so small that floor level is below the top of the wheels; this means there can be no doors above the bogies. The typical layout of two double doors towards the middle and two single doors at the ends of the cars was developed in the late-1920s. If the end doors were eliminated, there would not be enough doors.

Through gangways: these must have enough flexibility to accommodate horizontal and vertical curves as well as relative

movement between vehicles.

The bigger the overhang beyond the bogie, the larger the relative movement between vehicles and the longer the gangway. Having the single doors means long overhangs beyond the bogies; as a result, delivering both single end doors and gangways is virtually impossible.

Air conditioning: it has long been assumed that air conditioning produced too much heat to be dealt with in the small tube tunnels.

Even if this issue were to be solved, there was no space to accommodate the equipment.

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FEATURE

PHOTO: BRIAN HARDY

1938 tube stock with all-underfloor equipment, two double doors and two single doors.

And the solutions

(Inset) In the late 1990s, LU carried out a study aimed at maximising tube train capacity, christened the Space Train.

Starting with space first.

Bogies take up most space under trains, so could there be a solution that used fewer bogies? Articulation was the obvious answer, but this means that each car body must be shorter as there was little or no scope to increase the 10-11m bogie spacing. This meant that more cars were required, but there would still be fewer bogies providing an extra length of about 9m for equipment and about 5t in weight saved per bogie eliminated. End single doors would be eliminated, replaced by more double doors on the additional cars. Articulated

(Below) 1973 Piccadilly tube stock at Ruislip Manor, pictured after its refurbishment.

layouts make the gangway shorter because the movements that have to be accommodated are smaller and limited to rotational movements around the articulation centre.

Easy? No! LU’s early work showed that the typical articulation where the centre of the bogie is under the joint between the vehicles is not suitable for tube trains. To fit a bogie with the vehicle-vehicle coupling above it, the floor of the gangway above that and still achieve enough headroom in the gangway would be extremely difficult.

Also, articulated bogies (known as Jacobs bogies) often have a longer wheelbase than

their non-articulated siblings.

A longer wheelbase makes it hard to improve curving/trackfriendliness and the opposite of the ambition to reduce the wheelbase below the usual 1.9m. These issues led to a proposal where the bogie was wholly under one end of a vehicle and the other end would be supported from the bogie end of the next car. It was inspired by the Stockholm Metro C20 trains and is the configuration adopted for the new Glasgow subway trains.

The extra underframe space released by articulation helps to accommodate the air conditioning equipment.

Dealing with the heat is more of an issue. One helpful factor is the overall reduction of energy needed on a modern train with regenerative braking and where the power system and train are designed as a system.

That said, with an eventual 50% increase in train frequency from 24 trains per hour to

PHOTO: BRIAN HARDY

Rail Engineer | Issue 190 | May-Jun 2021

PHOTO: SIEMENS MOBILITY

FEATURE

36 (with new signalling), the overall power requirement - and therefore heat - will increase irrespective of the air conditioning. Some platform and tunnel ventilation and cooling schemes are likely to be needed to accommodate the increased frequency and any additional ventilation requirement for air conditioning would be a marginal extra cost.

Moving on By 2010, LU was confident in its development work and formed a team to take the project forward. After contract award in 2018, covering options for almost 250 trains, Siemens committed to a factory in Goole, East Yorkshire, and to build at least 50% of the Piccadilly Line trains there.

Since 2018, Siemens and LU have worked together to compete the trains’ detailed design. Construction of the factory has begun and the first apprentices recruited.

At the press event in March 2021 - which included a recorded message from the Mayor of London, Sadiq Khan - LU’s Managing Director, Andy Lord, and Siemens Mobility CEO, Michael Peter, launched the Inspiro London train design and described the key customer-facing features.

Subsequently, Rail Engineer interviewed Dave Hooper, Siemens Mobility’s Director of Major Programmes, to find out more. Engineers from the UK, Germany and Austria have worked together over the last year to complete the detailed design without any face-toface meetings as a result of the Covid-19 pandemic.

Dave Hooper couldn’t praise the joint teams highly enough.

He added that the experience has led to a completely new way of working which will persist once the pandemic has ended, blended with face-toface meetings where necessary to add further value. Dave thought the team working was absolutely vital on this project.

He had been programme director for the Thameslink Class 700 trains where a ‘platform’ design was customised for the Thameslink application, whereas the LU train is unique with a bespoke design for this customer alone and it makes perfect sense to work with the customer’s engineers so that Siemens may thoroughly understand the subtleties of the LU environment.

Configuration The Piccadilly Line train will be a nine-car, ten-bogie articulated train which will be 113.7m long, 2.844m high and 2.648m wide

over the external sliding doors.

Dave explained that Siemens came up with an innovative solution, having evaluated many options. It will be formed from five two-bogie motor cars with four intermediate cars - with no wheels - supported between adjacent cars. As far as your writer is aware, this is a unique configuration for a metro train, although it is relatively commonplace in tram and light rail vehicles.

Eight bogies will be motored, with the trailer bogies located under the cabs. The articulated couplings below floor level will accommodate yaw, pitch and roll, and one of the two couplings on each intermediate car will be supplemented by a device at roof level to control roll. The bodies will be formed of welded aluminium extrusions.

The exterior of the new Inspiro London.

And the bogies The bogies will be inside frame type, with a wheelbase of 1.80m using radial arm wheelset guidance supported with coil spring primary suspension.

The radial arm’s bushes will be of variable stiffness to allow a modest amount of passive radial steering. The secondary suspension will use rubber hour-glass-shaped springs, previously used on several LU fleets. Hydraulic dampers will

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FEATURE

1

Driving motor

2

Intermediate

3

Motor 1

4

Intermediate

5

Motor 2

6

Intermediate

7

Motor 1

8

Intermediate

9

Driving motor

Packaging the small underframes on tube stock is always a challenge and the layout has to reflect both the functions required and an even weight balance.

ATC equipment

Designation

Underframe

The distribution of equipment installed within the underframe.

Rail Engineer | Issue 190 | May-Jun 2021

Track monitor, deicing or flange lubrication

Car

technology with lithium-ion batteries and all lighting will use LED lamps. The three auxiliary power supply modules will each deliver 400V three-phase AC rated at 90kVA and 110V DC rated at 40kW. Through light weight, regenerative braking and lowenergy auxiliaries, Siemens claims that the new train will use 20% less energy compared with the old train after allowing for the power consumed by the air conditioning system.

The battery is primarily intended to provide power to the auxiliaries, but it can also move the train over a limited distance. This will be useful in depots - to move the train from the maintenance areas onto the conductor rails - and recover trains in tunnels between platforms in the event of power failure.

Brake equipment

The distribution of equipment installed within the underframe.

The 16 motors per train will be the three-phase permanent magnet type, driving the axles through double-reduction gearboxes. The motor and gearbox will be highly integrated and fully suspended on the bogie, driving the axles through a flexible coupling.

Each motor will be driven by its own inverter and there will be no unprotected line voltage cables carried between cars.

All bogies - except those on the central motor car - will have electrical power collector shoes which will be connected to a high-voltage (HV) box containing the main circuit breakers. The power is then fed to two traction converter boxes on the adjacent intermediate car.

A converter box contains two inverters and braking resistors, each feeding a traction motor on the adjacent bogie car. As an example, based on cars numbered 1

to 9, the shoes on Car 1 feed the traction converter boxes on Car 2 via the HV box. The inverters in one converter box feed the adjacent motor bogie on Car 1 and those in the other converter feed the adjacent motor bogie on Car 3. Similarly, shoes on Car 3 feed the converters on Car 4 which feed the motors on the adjacent bogies on Car 3 and Car 5. In this respect the train is symmetrical about the centre of Car 5.

Regenerative braking will generate up to 980V. Individual control of the motors allows very flexible control of dynamic braking in poor adhesion conditions compared with previous generations of AC drives where several motors are connected in parallel to the inverter, leading to the dynamic braking possibly being substituted by friction braking in poor adhesion conditions.

The maximum traction power will be 2.5MW and the top speed 100kph.

The auxiliary power will be provided by static converters using silicon carbide

Air supply

Electrical

TRAILER BOGIE

Battery

be used on both suspension stages. There will be single tread-brake units per wheel for brake blending and backup in case of dynamic brake failure and for emergency brake applications. There will be space for shoes, tripcocks, sleet brushes, wheel flange and wheel tread lubrication, and CBTC antennae.

Although the individual axle loads will be higher than usual due to the articulated layout, modelling has shown that the bogie’s running stability will be improved, making it much more track friendly than any previous LU bogie. Siemens is also working with LU to develop an active steering version which might be required on the Bakerloo and Central lines.

MOTOR BOGIE

Auxilliary power converter

The new train will be formed from five twobogie motor cars and four intermediate cars.

MOTOR BOGIE

DRIVING MOTOR CAR

Traction cases

MOTOR BOGIE

INTERMEDIATE CAR

HVAC

INTERMEDIATE MOTOR CAR

HV box and shoes

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FEATURE Passenger accommodation There will be a total of 18 passenger doorways per side, plus cab doors. The passenger doorways will be 1690mm wide, compared with 1446mm on the current Piccadilly stock.

There will be a multi-purpose area with tip-up seats in every car and four designated wheelchair spaces per train.

Overall there will be room for 260 seats - including tip-ups and 808 standing spaces at 5 passengers/m2; a total of 1,068 passenger spaces, an increase of over 20% on the old train.

The doors will be electrically powered, with door operators above the doors for the first time on a production tube train.

The exterior and interior appearance is based on work for LU by Priestman Goode and is what might be described as ‘a modern take on the traditional LU heritage design’, with appropriate use of Piccadilly Line blue throughout.

Passengers will find it easier to access the train and move around due to larger door openings and walk-through carriages. Floor height at doorway thresholds will be 700mm which is higher than the standard 520mm platform height; LU will be providing ‘humps’ next to designated wheelchair doorways in accordance with usual practice.

The other key customer benefit will be the air conditioning.

Passengers will also have digital information screens displaying real-time information as well as variable or even video adverts: no more staring at the same product for the whole journey! Dave Hooper also assured Rail Engineer that the seats will be cushioned and not ‘metro train’ plastic.

Reliability and depots LU set some tough reliability and availability targets, and Siemens said these will be delivered using redundant system design of vital components. There are also tough lifecycle cost targets

and Siemens is providing its Railigent® smart remote monitoring system to support optimising maintenance requirements and fault finding.

The aim is to detect anomalies remotely and get the train back to the depot in a planned way before a fault occurs. There will be a comprehensive train control and monitoring system which will also collect data about the performance of the

trains’ sub-systems and allow that data to be downloaded remotely via Wi-Fi. Finally, the train has provision for ATO/ATP equipment and retains provision for driverless operation at some point in the future.

Naturally the depots will need work. Northfields and Cockfosters will be upgraded to accommodate the longer trains and provide facilities for dealing with the different configuration of underframe equipment. This will take account of the fact that articulated through-gangway trains are much harder to separate into individual vehicles than the older, conventional trains. Dave Hooper observed that cars with no wheels are difficult to handle once uncoupled. London Underground is managing the depot upgrades with input from Siemens.

Car numbers Siemens and LU said that they expect the first new train to go into service in 2025.

They are also optimistic that, by then, funds will have been made available to order the trains for the Bakerloo, Central and Waterloo & City lines.

Rail Engineer wishes the joint project team every success and looks forward to seeing the trains for real in due course.

Finally, it is worth noting that the basic design would be the same for the Bakerloo Line - nine-car trains; the Central Line will have 11 cars and the Waterloo & City five cars. Car lengths will be adjusted for the Central line trains to conform to that line’s train length limits.

The train will accommodate 260 seats and 808 standing spaces.

The central seat bay with priority seats.

Thanks to Katie Byrnes and Laurie Waugh from Siemens, and Nancy Ryder and Claire Jermany from TfL for their assistance with this article.

Rail Engineer | Issue 190 | May-Jun 2021

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ELECTRIFICATION & POWER

Decarbonising SCOTLAND’S RAILWAY DAVID SHIRRES

PHOTO: JUI-CHI CHAN

46

L

ast July saw the publication of both Network Rail’s Traction Decarbonisation Network Strategy (TDNS) and the Scottish Government’s Rail Services Decarbonisation Action Plan.

Both reports concluded that rail decarbonisation requires electrification of a large part of the unelectrified network, with battery or hydrogen traction used on a smaller proportion of lesser used lines.

The key difference between these reports is that the former was a recommendation (from the rail industry to the UK Government) whereas the latter was an instruction (from the Scottish Government to industry).

The UK Transport Decarbonisation Plan was to be published in Autumn 2020 but has yet to appear. The Scottish Government published its National Transport Strategy in February 2020 which contains its vision for a sustainable, inclusive, safe and accessible transport system.

The delivery of this vision was explained at a recent virtual event organised by the IMechE’s Railway Division in Scotland which specifically considered rail decarbonisation.

At this event Bill Reeve, Transport Scotland’s Director of Rail, Alex Hynes, Managing Director, Scotland’s Railway, Syeda Ghufran, ScotRail’s Engineering Director and Katie Vollbracht, Principal Programme Sponsor for Network Rail Scotland, explained how the programme to give Scotland a zero-carbon railway by 2035 is being delivered.

Leading the charge in the decarbonisation of the UK rail network www.arqrail.com

ELECTRIFICATION & POWER

Scotland’s net-zero transport story Bill Reeve opened the event by referring to the vision in the Scottish National Transport Strategy for a sustainable, inclusive, safe and accessible transport system that reduces inequalities, takes climate action, delivers inclusive growth and improves health and wellbeing, and how these objectives are interlinked. For example, better decarbonised public transport reduces both carbon and harmful diesel emissions, and encourages people to walk and cycle. He explained how the strategy guides policy and investment decisions with a transport hierarchy of walking, cycling, public transport, taxis and shared transport, and car.

In Scotland, transport accounts for 37% of all greenhouse gas emissions.

Of this, cars, vans, and HGVs account for 65%, air and shipping 30%, with buses and rail accounting for 3.2% and 1.2% respectively. On the roads, Scotland plans to phase out new petrol and diesel cars

and Barrhead schemes. Bill stressed the importance of keeping electrification costs down and notes that Scotland’s rolling programme has enabled teams to ‘learn as they do’ which is a good way of driving down costs.

He emphasised that railway costs have to be kept down to ensure the overall sustainability of the railway business. In this respect, electrification was not just about the environment.

Electric trains cost less to buy and run, are faster and attract more passengers. They also enable longer freight trains to be run at higher speeds, THURSO resulting in more trains on existing infrastructure.

WICK Bill noted that he is often asked how Scotland can afford to electrify its network, to which his answer is that we simply INVERNESS THURSO can’t afford not to.

by 2032, introduce low emission zones and accelerate the deployment of zero-emission buses across Scotland. It also aims to decarbonise flights within Scotland by 2040.

As rail has such a low emission share, Bill noted that it might be thought that action to decarbonise rail was not a KYLE OF priority. Yet, LOCHALSH as he pointed out, zero transport emissions is unlikely to be possible without MALLAIG some measure of modal shift to get people and goods off the WILLIAM roads. Freight FORT decarbonisation KYLE OF LOCHALSH requires a differently-managed logistics distribution system PERTH MALLAIG which takes goods out of OBAN STIRLING HGVs and light vans onto a FORT WILLIAM decarbonised rail network. This GLASGOW requires more rail electrification.

Since 2010, Scotland has KILMARNOCK OBAN delivered over 500 singleAYR track kilometres (stk) of GLASGOW electrification. This started with the new Airdrie-Bathgate KILMARNOCK railway which opened in 2010 AYR STRANRAER CARLISLE and was followed by Paisley Canal, Cumbernauld, the Edinburgh-Glasgow main STRANRAER line, Stirling-Dunblane/Alloa and Shotts. Work has now started on the East Kilbride

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The Airdrie-Bathgate line was electrified as it was built in 2010 and was the UK’s first electrification scheme for almost 20 years.

The Scottish Government’s rail decarbonisation plan.

ELECTRIFIED ELECTRIFICATION 2021-35 TRANSITIONAL TRACTION SOLUTION PERMANENT TRACTION SOLUTION ELECTRIFIED WICK

ELECTRIFICATION 2021-35 TRANSITIONAL TRACTION SOLUTION

ABERDEEN

PERMANENT TRACTION SOLUTION

INVERNESS

ABERDEEN

DUNDEE EDINBURGH

PERTH STIRLING

BERWICKUPON-TWEED DUNDEE

EDINBURGH BERWICKUPON-TWEED

NEWCASTLE

CARLISLE

NEWCASTLE

In choosing ARQ, you are choosing to do things differently.

To help meet the targets set by the UK government, a new collaborative partnership, comprising three leading rail companies within the Renew Holdings Group, has been launched.

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ELECTRIFICATION & POWER

Scheme

Output

Date

Scheme

Output

WOFE

Alloa-Longannet EMU operation

Levenmouth

Passenger services

Dec’23 East Linton New station

Glasgow-Barrhead EMU operation

May’23

A2CB

Fife

BEMU operation

Dec’24

Dalcross

Borders

BEMU operation

Dec’24

Aviemore Accessibility/footbridge

Barrhead

East Kilbride

Glasgow-East Kilbridge EMU operation Maryhill Maryhill branch EMU operation 1 timetable Far North Phase improvements

TBC

Forth South Queensferry bridge Bridge VE walk

May’24

Freight Gauge

TBC

Commence AberdeenCentral Belt journey time

Date May’22 Dec’22 Apr’23

New station & passing loop Dec’22 Dec’23

Phase 2

Mar’24

Pitlochry

Accessibility/footbridge

Mar’24

Sep’21

Carstairs

Junctions renewal

Sep’24

Dec’21

2 timetable Far North Phase improvement

Mar’24

Reston

New station

EWWA

Commence TAWS process Rephase

D to P

Dunblane turnback

Phase 1

GLAB

Portobello/Niddre/Millerhill Mar’24

Freight Gauge Cornton No.1

Mar’22

Commission new MCB-OD May’22 level crossing

Network Rail Scotland’s short-term project plan.

TBC

Decarbonisation contribution

Whole system approach Network Rail Scotland’s Principal Programme Sponsor, Katie Vollbracht, emphasised that delivering rail decarbonisation requires a fully integrated approach to the whole railway system to provide the required infrastructure and rolling stock to meet enhanced timetable requirements by 2035. Such timetables will be needed to accommodate and attract passengers and goods to drive the required modal shift for Scotland’s decarbonisation programme.

This needs more reliable and quicker trains, as well as more paths and a gauge clearance programme for freight. She advised that the whole pipeline for rail investment in Scotland supports these goals for which route strategies were considering all options.

These strategies are looking at infrastructure enhancements to be done prior to electrification such as freight loops, gauge clearance and signalling. All options are being examined to achieve full electrification, including discontinuous electrification as a transitional strategy. This has to take account of the future availability of rolling stock, such as Battery Electric Multiple Units (BEMUs) and the timescales and locations for electrical feeder stations. Feasibility work is considering the timing and order of the required route enhancements and electrification.

Katie advised that the short-term priorities over the next five years are the electrification of the East Kilbride and Barrhead lines, and eliminating diesel traction on the Borders and Fife lines.

The heavily graded 30-mile Borders Railway is too far for BEMU operation and was built with passive provision for electrification, though may initially have partial electrification with BEMUs. One option for Fife is electrification of the main line to Dundee, with BEMUs operating on the Fife Circle and the new Levenmouth branch which is due to open in 2024. In the longer term,

Electrifying Glasgow Queen Street Tunnel on the Edinburgh-Glasgow main line, on which electric services started in December 2017.

Leading the charge in the decarbonisation of the UK rail network www.arqrail.com

ELECTRIFICATION & POWER

options for routes to Inverness and Aberdeen depend on the availability of rolling stock.

Scotland’s plan to decarbonise its railway requires 1,800 single-track kilometres of electrification, with 18 feeder stations and 30 track sectioning cabinets. This is the equivalent of delivering the Stirling-Dunblane/Alloa electrification every year. There are also 560 potential bridge reconstructions. Contracts have already been let for East Kilbride, Barrhead, Maryhill, Borders, Fife, Kilmarnock and Dunblane-Perth (400 stk); the Fife lines are out to tender (165 stk) and the PerthAberdeen remit (350 stk) is being prepared.

Katie acknowledged that integrating infrastructure, rolling stock and timetable requirements is a bold programme with many challenges. It requires everyone to be adaptable, efficient, and quicker when developing and delivering schemes, and to take full advantage of innovations, particularly those

offering more cost-effective electrification. Procurement is also a huge challenge for both infrastructure and rolling stock, although it offers huge opportunities for the supply chain and the economy.

Replacing the diesels ScotRail’s Engineering Director, Syeda Ghufran, described the number for diesel units that will be life-expired within the next 10-15 years.

These are 43x Class 156 (2026), 40x Class 158 (2030), 25x HSTs (2030) and 34x Class 170 (2035).

She advised that ScotRail is developing a fleet strategy in conjunction with Transport Scotland and Network Rail which will set out plans to replace diesel traction on routes being electrified. This will also consider alternative green traction to decarbonise certain routes ahead of full electrification and also on routes where there is not an economic business case for full electrification, such as the Far North and West Highland lines.

This is focusing on the introduction of an electric fleet coupled with targeted battery and hydrogen technology. Its scale is quite significant as not only are there 142 diesel units to be replaced, but 55x Class 318/320 EMUs operating on the Strathclyde network also need to be replaced between 2025 and 2030.

Syeda also stressed the requirement for initiatives to reduce the emissions from the diesel units before they are withdrawn, such as the use of additives which will also be part of the rolling stock decarbonisation plan.

She noted that there had been a lot of interest in alternative traction, with hydrogen and batteries being the only zero-carbon option for self-powered multiple units.

Battery EMUs are also being considered; these charge their batteries whilst operating on electrified lines. Both these traction types would require new support infrastructures such as battery charging points and hydrogen production and

Scotland’s hydrogen demonstration train.

ARQ brings a fresh and innovative approach to the UK rail sector.

This new partnership, involving AmcoGiffen, Rail Electrification Ltd (REL) and QTS, provides a truly integrated self-delivery model to decarbonise and electrify the UK rail network.

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ELECTRIFICATION & POWER

A Class 385 EMU at Glasgow Queen Street.

fuelling. Their costs and different operating models need to be carefully considered in respect of timetable requirements and operational resilience.

The range of hydrogen and battery traction is considered to be respectively 400 and 55 miles.

However, the consensus view of manufacturers is that it is likely that there could be significant developments in battery technology in the next 5-10 years. ScotRail is also considering rapid battery charging such as the Vivarail system (Issue 186, Sept/Oct 2020).

ScotRail considers that EMU, BEMU and hydrogen units will cost respectively £1.32, £1.62, and £2.46 per mile to operate. Syeda noted that EMUs stand out as a more cost effective and reliable option as they collect electricity on the move from fixed current collection systems without incurring any significant losses. These are operational costs only and do not include capital cost for the required infrastructure.

She advised that, as with any new train introduction, there will be challenges that need to be addressed. Hence there has been early engagement with potential suppliers to understand what they have to offer, to develop technical specifications. ScotRail is

also in consultation with designated bodies to understand the safety approval strategies for novel train technologies. ScotRail is working closely with Network Rail to determine depot and stabling requirements as well as undertaking a route analysis which includes, for example, gauging and signalling requirements.

ScotRail’s plan to deliver and replace 200+ units within the required timescales to decarbonise Scotland’s railway is certainly ambitious.

However, as she stressed, this will improve overall performance and generate capacity.

The climate imperative The event was concluded with a presentation from Alex Hynes, Managing Director, Scotland’s Railway, which underscored the importance of climate action. His presentation showed forecasts of rising global temperatures and quoted John Kerry, Joe Biden’s Special Climate Envoy, who had said that COP26 - this year’s world environmental summit in Glasgow “would be the last best chance to do something about it.” Alex stressed that climate change was not just a long-term problem that affected others and he reflected on the recent tragic event at Carmont which was the result of extreme weather.

Leading the charge in the decarbonisation of the UK rail network www.arqrail.com

Leading the charge in the decarbonisation of the UK rail network

In choosing ARQ, you are choosing to do things differently.

Decarbonisation is huge focus for the rail industry over the next 30 years, as the UK government aims to remove all diesel only trains by 2041, with a legally binding commitment to Net Zero by 2050. It has been recognised by the industry that together, we must do more to be part of the solution to climate change.

To help with the targets set by the UK government a new collaborative partnership, comprising of three leading rail companies within the Renew Holdings Group, has been launched.

Everything taken care of via in-house delivery & strategic partnering with framework suppliers • Advanced Works

• Stations

• OLE Design

• Structures

• Earthworks

• P-Way

• OLE

• Power

• Signalling

For further information visit www.arqrail.com

info@arqrail.com

A unique family of businesses Individually, we have provided expert services enable electrification programmes across the UK.

AmcoGiffen

REL

QTS

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ELECTRIFICATION & POWER

Slab track and tracklowering through Bowshank Tunnel creates passive electrification provision for the Borders Railway.

Scotland’s railway has been decarbonising since 1960 when electric ‘Blue Trains’ were introduced on Glasgow suburban services.

Since then, the city’s electrified network has grown to be the largest urban rail network in the UK outside London. £8 billion has been invested on Scottish rail enhancements since 2007 which includes hundreds of kilometres of electrification. As a result, 76% of Scotland’s passenger journeys and 45% of its rail freight is on electrified lines.

Alex advised that Borders has been a huge success, with more coaches added at every timetable change. He advised that it now justified eventual full electrification and that, as a minimum, battery EMUs will be running on the line by 2025, ten years after it opened.

The Borders Railway’s passive provision for electrification will reduce costs when it is electrified.

He felt that the Scottish Rail Services Decarbonisation Action Plan, published in July 2020, was an extraordinary piece of political, environmental and transport leadership, and was pleased to see Transport Scotland, Network Rail and ScotRail collaboratively working together to bring it to life. Perversely, Covid had created an opportunity to put some projects on the back-

burner and place decarbonisation projects at the front of the queue which will make the railway attractive enough to drive modal shift.

His presentation included a pipeline of short and medium-term projects which highlighted decarbonisation projects, including electrification from the central belt to Aberdeen and Inverness.

Although continuous electrification is the best way to do this, combining the decarbonisation programme with the rolling stock programme determines the optimum way to electrify.

Alex noted that, in an ideal world, Aberdeen electrification should be completed by 2030, yet the route has to be decarbonised by 2030 when HSTs are life-expired. The interim discontinuous electrification solution is the result of collaborative work to determine what may be the optimum development of infrastructure projects and rolling stock strategy to meet the timetable requirements.

Alex assured his audience that an enormous amount of work is being undertaken behind the scenes to develop Team Scotland’s decarbonisation programme at a cost acceptable to the Scottish Government.

Making Scotland’s railway greener in this way is a hugely exciting agenda which builds on the successes of past.

Leading the charge in the decarbonisation of the UK rail network www.arqrail.com

ELECTRIFICATION & POWER Team Scotland’s plan All these presentations demonstrated how Transport Scotland, Network Rail and ScotRail are working together to deliver a common integrated plan, with a pipeline of projects visible to the supply chain. Transport Scotland’s Bill Reeve often says that, in Scotland, decarbonisation is spelt E-L-E-C-T-R-I-F-Y; yet it requires much more than that.

Gauge clearance and loops for rail freight, signalling work and other capacity enhancements are needed prior to and during electrification works, and, crucially, the programme must be aligned with a rolling stock strategy.

South of the border, the Railway Industry Association (RIA) has, for a long time, campaigned for both a rolling programme of electrification and for the supply chain to have visibility of the DfT’s pipeline of rail enhancement projects. On its website, RIA has an enhancements clock which shows that, at the time of writing, the DfT’s rail enhancements pipeline

was last updated 564 days ago. The DfT has also yet to respond to Network Rail’s TDNS study which was submitted 280 days ago.

Despite it being the only decarbonisation solution for most of the rail network and, as shown in TDNS, having a good business case, the Westminster Government has shown reluctance to commit to further electrification due to doubts about its affordability. The Great Western electrification programme’s cost overrun casts a long shadow.

Yet not only have recent electrification schemes been delivered to budget, Team Scotland has shown the importance of having an integrated strategic plan. The 2018 long-term passenger rolling stock strategy shows that 4,600 rail vehicles are over 30 years old. Without a plan for their replacement, it is likely that large sums of money will be wasted on the wrong trains.

The £13 billion recently spent on 7,000+ new rail vehicles indicates the potential for such additional costs.

PHOTO: GEORGE CLERK

“The ARQ partnership has been created in order to support Network Rail’s decarbonisation agenda and we have the ambition to help push forward the change required to drive this commitment.

“Reaching net zero by 2040 is an exciting challenge and opportunity for the rail industry to invest in innovative thinking and technology to drive down time and cost of electrification schemes. ARQ has the skills within each of our businesses to do this, but crucially, we also have the drive and commitment to bridge the skills and knowledge gap in the industry. We have access to an existing large in-house training facility with plans to expand it, which will enable us to further invest in training and develop sustainable skills for the future.

“We need to explore further innovation in the design and build process. We must be able to accurately design in a virtual world, build (where we can) off the railway and then use the access time efficiently whilst maximising productivity, ensuring minimal disruption to passengers and freight.”

Vinny O’Holloran, Operations Director, ARQ

The DfT has produced a 2020-2025 Road Investment Strategy pursuant to the 2015 Infrastructure Act, but there is no equivalent rail strategy for England and Wales, nor does this Act require one. As Team Scotland has shown, it is not possible to deliver decarbonisation in a costeffective manner without an integrated strategic plan for electrification, other infrastructure work and rolling stock to meet the enhanced timetable requirements needed to accommodate the required modal shift.

A fleet strategy will look at decarbonisation on routes where there is not an economic business case for full electrification.

Team Scotland’s webinar, Decarbonising Scotland’s Railway, can be viewed on line at the Railway section of www.imeche.org/webinar-hub

ARQ – an electrifying new partnership for UK rail.

Accelerating the move towards electrification, this new collaborative partnership aims to help Network Rail in its response to the UK decarbonisation agenda.

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ELECTRIFICATION & POWER

CLIVE KESSELL

A BIG STEP FORWARD

A

rticles on electrification invariably focus on 25kV overhead systems or indeed the modern-day 50kV auto-transformer variant. The safety procedures that go with these are well documented and accidents are thankfully very rare. We must remember however that a significant percentage of the UK electrified railway uses live conductor rails positioned on the outside of one or other of the running rails. These carry 750V DC and are capable of delivering many thousands of amps.

Conductor rail isolations can be time-consuming and reduce productive work time.

Whilst the majority of this third rail network is on the ex-Southern region, we must not forget Merseyrail Electrics and the Euston-Watford DC lines. There is also, of course, the London Underground network using the fourth

Rail Engineer | Issue 190 | May-Jun 2021

rail configuration plus the Docklands Light Railway with at least the electric pick up being on the underside.

Can you imagine what the Health & Safety Executive would pronounce if you were to go to them with the third

rail system as a new invention and ask for safety approval? An openly exposed high-voltage rail at shin height without any form of protection would be laughed out of court. Yet this is a day-to-day reality for many trackside workers who have to maintain the permanent way, under-track cable crossings and such like. Is it any wonder that despite the rules for access and taking of isolations, accidents do occur from time-to-time with very serious consequences.

My own time on the Southern Region in the 1980s occasionally meant going on the track and a very big step was taken to get over the live rail. If this is something you have to do on a daily basis, the old adage of familiarity breeds contempt might just kick in.

For signal engineers, the third rail is an ever-present reality.

A talk was given recently to the IRSE London & SE section

by Neil Clegg, who has a background in Electrification & Plant engineering, to tell of a safety improvement that is making trackside work less vulnerable to contact with the live rail.

ELECTRIFICATION & POWER

NSCD control panels, one with key locks.

Existing procedures Routine track maintenance is often carried out with the third rail still live. Rules make clear what types of work staff can or cannot do, the safeguards to be implemented and extreme care that must be taken. For any significant work, an isolation - switching off the current - must be made. This requires the cooperation of the staff on site and the Electrical Control Operator (ECO).

To know what is involved, we must first understand the basic layout of a third rail power arrangement. From the national grid 400kV or 132kV transmission lines, 33kV or 11kV power

cables are installed into lineside substations.

Sometimes these cables are part of the railway infrastructure and run in trackside troughing routes. The substations are typically 3-4 miles apart and incorporate a transformer rectifier to obtain the 750V DC. Circuit breakers protect this supply before the connection is made to the third rail and will open when fault conditions occur, for example a short circuit between the live rail and the running rail.

Bear in mind that a DC train needs a lot of amps when accelerating from a station stop and the system has to be capable of delivering that power. Between the substations are Track Paralleling Huts (TPH) which enable the third rail to be sectioned to increase the track voltage regulation between substations, i.e. keep it within the standards prescribed for the trains.

Robust, rapid, pivoting, retractable, elegant & highly conductive — Furrer+Frey’s Rigid Overhead conductor Rail system ROCS is renowned throughout the world for its superior standards of quality & reliability.

In tunnels, in stations, in the open, on bridges, in workshops and depots, ROCS can easily adapt to any structure.

Furrer+Frey has supplied its groundbreaking ROCS system for more than 3400km of track across the globe and it is currently tested up to 302kph line speeds.

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Rail Engineer | Issue 190 | May-Jun 2021

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ELECTRIFICATION & POWER The Negative Short Circuit Device

NSCD racks at Godinton...

West Dulwich...

To arrange a track possession, a power isolation is required and this is achieved by a two-way procedure between the Person in Charge of the Possession (PICOP) and the ECO. The operator will open the breakers for the section required whereupon the Engineering Supervisor (ES) gets authority to instruct staff to test locally with a Live Line Tester (LLT) where straps will be applied; then a short circuit bar is placed between the third rail and adjacent running rail to protect against any inadvertent switch-on. Short circuit (SC) straps are then applied and the bar can be removed thereafter.

All of this takes time and is backed up by communication procedures and logged on the appropriate forms.

Incidents do arise and can be caused by: » the SC straps being applied before the short circuit bar is in position » the SC straps being applied at the wrong location » no live voltage test being carried out » the rails not being brushed to ensure a good connection » the SC straps being applied but not tightened.

Rail Engineer | Issue 190 | May-Jun 2021

To overcome this somewhat clumsy arrangement, a new process involving a Negative Short Circuit Device (NSCD) is being introduced to effectively replace the short circuit straps.

They are controlled from a Local Control Panel (LCP) which are situated in green zone areas, predominantly at access points.

The LCPs control the NSCDs which are short circuit switches wired between the track side of the DC circuit breaker and the negative bus bar at substations and TPHs. The LCP enables the PICOP to make an isolation from a position of safety and not needing to go on or near the line.

An electrical interlock prevents the NSCD from being operated before the ECO opens the power feed circuit breaker. The NSCD equipment is housed in a cabinet comprising the switching components that are wired in parallel with the normal feed to the rail, which then connects via the negative bus bar to complete the short circuit. The LCP includes a toggle switch on the front of the cabinet showing a green light when the NSCD is open, a red light when the conductor rail is live and a yellow light to indicate any lamp failure. When

the NSCD is operated, a white ‘shorted’ lamp is illuminated.

The toggle switches are controlled by a local lockout/ remote selector switch which is secured by a lock and key.

Good labelling is an essential part of the system to ensure there is no confusion as to the site or live rails being protected.

To enable the NSCDs to protect two simultaneous possessions and associated isolations, two key boxes are installed - red and yellow that allow a double-locking arrangement so as to protect inadvertent switch-on if one of the isolations is no longer required.

Two types of NSCD are available: » B4 - an NSCD is installed for an electrical section. It is wired in parallel with the normal feeds to the rail from either a substation or a TPH » B5 - only one NSCD is installed between the positive and negative bus bars at substations. Currently the safety case is being assessed on the requirement to provide B5 NSCDs at TPHs. The NSCDs are manufactured either by HSS (Hawker Siddeley Switchgear under the Brush parent company banner) or by LCS (L C Switchgear).

ELECTRIFICATION & POWER Advantages and actions required All NSCDs are operated from the LCP which is interlocked with the circuit breakers. It is a quick operation and they negate all risks associated with the placement of SC straps. These can still be applied at the extremities of an isolation if additional assurance is thought to be required.

The procedure is as follows: » the PICOP takes the possession and makes a request to the ECO » the ECO opens the applicable circuit breakers » the ECO instructs the PICOP to close the NSCD » the PICOP informs the Engineering Supervisor of the NSCD status » work can commence.

...and South Bermondsey.

Implementation

At the end of the possession, the reverse procedure is followed, ending with the PICOP informing the ECO that all NSCDs are now open; thereafter, the circuit breakers can then be closed to restore the traction current.

Should a NSCD fail to open at the end of an isolation, emergency procedures are in place to re-energise the circuit breakers so that power can be restored to the trains. At present, the ECO does not have remote monitoring of the NSCDs so a verbal assurance is required. It is the intention that with the rollout of the SCADA programme, this facility will be provided to add another safeguard.

To date, the London-Brighton main line and branches have been equipped with NSCDs, along with parts of the Kent lines. The provision of NSCDs on the South-West lines is in the CP6 programme. Rollout across the whole of the ex-Southern Region should be completed by the mid-2020s. It is expected that the Merseyrail and Euston-Watford lines will be similarly equipped in due course.

There will always be risks with the safety of staff in third rail traction areas so NSCDs are not the ultimate protection. They are however a big step forward in improving safety procedures for this type of electrification.

Arthur Flury forked collar sockets and conical couplers Holding the OLE securely for more than 50 years around the world, forked collar sockets and conical couplers from Arthur Flury are embedded in all of the UK’s electrified routes.

The cone holds the conductor tight and engineering tests have consistently verified that the conductor will break before slipping from the cone.

Manufactured in our ISO9001 appoved factory, Arthur Flury forked collar sockets and conical couplers hold full product acceptance with Network Rail and are included in OLEMI, Series 2 and Series 1 catenary designs.

Please contact our Milton Keynes office for further information.

aflury.co.uk

info@aflury.co.uk

Arthur Flury (UK) LTD

Rail Engineer | Issue 190 | May-Jun 2021

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ELECTRIFICATION & POWER PHOTO: ANDROMEDA

PETER STANTON

overcoming THE CLEARANCE ISSUE

W

hilst third rail and other low-level current collection systems add a lot of equipment to a railway at ground level, the general approach to electrification across the world has involved the adoption of overhead contact systems. In the UK, the early schemes tended to consist of installations at relatively low voltages and the clearance from surrounding structures was not a significant challenge.

Rail Engineer | Issue 190 | May-Jun 2021

from the emerging costs and engaged in much significant development effort. This culminated in modified design protocols for the extension of the early work to complete the Euston-Birmingham route.

The early clearances were foreshadowed at a conference held in 1960 by the Institution of Mechanical Engineers and permission was obtained from the Chief Inspecting Officer for Railways to experiment with a view to determining minimum safe clearance dimensions. As presented in the follow-up electrification conference in 1966, revised electrical clearances were approved by the Minister of Transport in August 1962. This PHOTO: NETWORK RAIL

Cardiff Intersection Bridge carries the CardiffMerthyr line over the South Wales Main Line.

However, technical advances arising from the need for higher speeds and heavier loads led the industry towards high-voltage overhead line equipment (OLE) which demanded much greater clearances. The initial highervoltage installations accepted what would nowadays be quite conservative clearances for live equipment and consequently the early stages of the West Coast Main Line electrification involved a considerably quantity of overbridge reconstructions.

The media was enlivened by images of exploding bridges whilst clever solutions for prefabricated new arches were introduced.

British Railways - as it then was - realised that the case for further electrification was at risk

Lower voltage

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ELECTRIFICATION & POWER

PHOTO: ANDROMEDA

PHOTO: GOOGLE EARTH/LANDSAT/COPERNICUS

allowed the London Midland Region electrification to be completed at 25kV throughout and advantage was gained from the acceptance of the new dimensions for all domestic schemes.

In a precursor to current times, incisive questions were posed about the cost of electrification and, as well as installation and equipment costs, the need to create clearance was examined closely.

One solution had been to employ a lower voltage and, in place of the standard nominal 25kV, equipment was installed to provide traction power at 6.25kV - an approach employed on the Great Eastern Lines and in Scotland for the Glasgow suburban projects.

The London, Tilbury and Southend Lines were also thus equipped; the 6.25kV section was from Fenchurch Street to beyond Barking, with changeovers there on both the Upminster and Tilbury lines, together with a section between Chalkwell and Shoeburyness. The remainder was at 25kV and the 6.25kV sections were converted to 25kV in the early 1980s.

However, this apparently attractive project introduced unwanted complications, particularly the application of

dual voltage capability to rolling stock and the requirements for changeover equipment.

The search therefore continued for the ability to install overhead line equipment with lower clearances to fixed infrastructure.

Electrification of the East Coast Main Line emerged with costs acceptable to government and, for a while, electrification rolled forward; however, it slowed considerably during the era of privatisation and the splitting of British Rail into infrastructure and other portions.

Eventually, under influences from the need to consider the environment more fully, electrification began to restart, albeit under close cost examination. As the challenges to the cost of electrification grew and the go-ahead was given for proposals on the Great Western and Midland main lines, as well as schemes such as ‘the electric spine’, the search for solutions to reducing clearance were pursued with greater vigour. As has been described elsewhere, electrification costs came under even more scrutiny and the situation became more serious with much proposed work being cancelled.

An overview of the railway layout.

The view west towards Cardiff Central.

Bridging the gap However, the industry was determined to prove that costs could be controlled and an opportunity to show how arose within the Great Western Electrification Programme (GWEP). Recently projects have shown that civils work - especially bridge reconstructions - can make up around a third of the cost.

One example is the Cardiff Intersection Bridge, a substantial skewed crossing of the Cardiff and Merthyr line

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ELECTRIFICATION & POWER

The trial of a coated steel plate at Paisley, Scotland.

with the South Wales Main Line. Initial plans to reconstruct the bridge were estimated to be around £40 million. Alternative proposals involved lowering the track, rebuilding a culvert and pumping water from the canal around Cardiff city centre, which was estimated to cost around £20 million. Both solutions would be very disruptive to passengers and the costs threatened the viability of continuing the electrification west into Cardiff Central Station, only 400 metres away.

The challenge was met by a group consisting of Andromeda Engineering of Speke (Liverpool), GLS Coatings, Great Western Railway, Network Rail (Infrastructure Projects, Safety Technical & Engineering (STE) and Wales & Western Route), Pace Networks, Siemens Mobility and the University of Southampton (UoS) High Voltage Laboratory.

Andromeda Engineering, GWEP’s OLE designers for Cardiff, and Network Rail (Wales & Western), contacted Network Rail (STE) to propose an alternative design - initially in the form of a proof of concept - to avoid further descoping of the programme. A steering group was formed to bring in all the decision-makers and focus on achieving an engineering solution.

STE identified modern equipment from Europe that could assist with the challenge. This included: » Bonomi insulated bridge arms, supplied by Pace Networks, » Siemens 25kV surge arrestors, complete with Siemens Arrestor Condition Monitor (ACM) » an electrically-insulating coating from GLS Coatings (GLS 100R) that Network Rail had previously used for signalling power supplies.

Making sure The solution identified the benefits of utilising the latest insulation coating technology to provide an electricallyinsulating layer to the bridge to support

Rail Engineer | Issue 190 | May-Jun 2021

reduced electrical clearance. This was the first proposal of its kind for new electrification. Surge arresters were included in the design to ensure potential transient over-voltages at the bridge could be safely controlled without the need for additional clearance.

Suppliers agreed to submit their equipment to high-voltage electrical testing devised

by Network Rail (STE) and the University of Southampton.

The Siemens surge arrestor is a recent development. When installed at bridges or tunnels, they significantly reduce the impact of over-voltages, for example from a lightning strike. They were recently installed on the Danish railways to reduce static electrical clearances from 270mm to 150mm.

The testing at the UoS High Voltage Laboratory included combinations of components from different suppliers to determine the optimal arrangement. Each was tested in dry and wet conditions, with a pollution mix added to contaminate all insulating surfaces in order to make the tests as realistic as possible.

They delivered much better results than expected. When all the equipment was used together as a system, a minimum clearance of just 20mm was proven as sufficient to avoid flashovers in wet and polluted conditions.

However, even this was insufficient to energise the OLE under the bridge. It was proposed to install the contact wire at a reduced height.

Standard deviation Andromeda confirmed in their proof of concept design that if a case could be made to deviate from the RSSB Group Standard minimum OLE wire height requirement, a design could be developed which interfaced with the railway in the vicinity of the bridge. Additional high-voltage testing was developed by Network Rail (STE), UoS and GWR involving the minimum electrical clearance required between the OLE and various train roof gauges. These tests confirmed that the surge arrestor connected to the OLE provided an additional benefit and only 70mm was needed to avoid flashovers between the OLE and top of rail vehicles.

To gain confidence in the design, Network Rail (Scotland) agreed to carry out an inservice trial which included lowering a steel plate coated in GLS100R closer to the OLE in stages. This simulated a metallic bridge and proved the concept on an operational railway.

It provided Network Rail (Wales & Western) with the confidence to proceed and agree for the bridge to be coated. GWR provided further assistance by working with their suppliers to confirm that pantographs would be able to operate satisfactorily under the lower wire and supported Network Rail with the necessary deviation to RSSB.

ELECTRIFICATION & POWER

Award winning specialists in multidisciplinary railway design and consultancy

Innovative engineering for tomorrow’s railway www.andromedauk.com

info@andromedauk.com

Andromeda Engineering Ltd

@andromedauk.com

Rail Engineer | Issue 190 | May-Jun 2021

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PHOTO: ANDROMEDA

A clearance of 20mm was proven to be sufficient to avoid flashovers.

Working together Adopting a collaborative approach to utilising innovation, managing risk and decision making was vital in securing support from a wide range of stakeholders for the unconventional proposal.

With acceptance of the solution, the key to the success of the project was commitment by Andromeda Engineering to positive stakeholder management, ensuring everyone would be satisfied with each stage of the works.

The assembly of a Strategy Steering Group and Delivery Working Group ensured a topdown approach would be adopted to facilitate collaboration. The groups met regularly to discuss the key areas, making sure that clear and concise deliverables for implementation emerged. The approach also realised significant efficiencies and demonstrated what can be achieved when industry partners come together with a common goal.

Estimates suggest that the approach led to considerable savings, as well as preventing significant disruption to the railway and

Development and installation cost less than £1 million.

PHOTO: ANDROMEDA

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derisking the programme. The total cost of development and installation was less than £1 million, equating to a 95% cost efficiency.

The OLE was energised under the bridge in December 2019. So far, there have been no flashovers and the design has worked perfectly. The route is still clear for all standard rail vehicle gauges despite the reduced wire height.

The significance of the project was acknowledged by Andromeda Engineering becoming winners of the Railway Industry Innovation Award in 2018 and finalists in the ‘Driving Efficiencies’ category at the Rail Partnership Awards in the same year.

The concept of Voltage Controlled Clearances (VCC) has been adopted by future electrification projects, including TransPennine and in Scotland. Collectively, it is estimated that VCC could save over £100 million. It will therefore play a pivotal role in making electrification more efficient and help to decarbonise the railway.

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ELECTRIFICATION & POWER The EC7BW18-ECRT/ EDRT DC-DC converter.

JOHN STONE

Bringing all tracks together

O

ne of the biggest design challenges for power supply manufacturers in a global rail industry is that train-borne applications around the world have different battery voltage parameters across different vehicle classes. Manufacturer Cincon developed the EC7BW18-72 board-mount 20W DC-DC converter series which includes models for all

common voltages, from a single 12V battery for automotive vehicles up to 110V systems for electric trains and an ultra-wide input range of 8.5-160V DC.

Now the converters are available as a complete solution in a one-size-fits-all format for all voltages and all classes of trains. The EC7BW18-ECRT/ EDRT 20W universal input DC-

DC converters are a turnkey solution for power for the railway industry. Available from Relec Electronics, the power supplies are available in chassis and DINrail mount formats.

The company developed the DC-DC modules as an all-in-one 20W power solution suitable for system engineers as well as board-level designers. The family has been developed around the proven EC7BW18-72 series 2” x 1” DC-DC converters, with the addition of a rugged case and additional components.

As well as reducing time to market, the EC7BW18ECRT/EDRT series saves ‘bill of materials’ costs because they do not require additional components. The converters meet the requirements of EN50155, EN50121-3-2 and EN45545-2 for immediate use, presenting a turnkey integrated solution for system designers.

Instead of multiple power supplies, a single unit with an input range of 10-160V is capable of meeting the nominal input ranges from 24-110V for EN50155. In addition, each module will also meet the requirements of RIA12 surge A (3.5 x Vin for 20ms) for 24V and 52V systems. This represents savings in inventory as well as ease of design for international manufacturers.

Construction The DC-DC converter series has been designed to be compliant to EN50155, with built-in inrush current limiter, hold-up circuit and EMC solution to EN5021-3-2 integrated into a single chassis or DIN-rail mounted package.

In order to comply with EN50155, a device must pass a number of type tests relating to temperature, humidity, vibration, shock and electrics. These

The effects of inrush current with (top) and without (bottom) a limiter on input voltage (yellow), current (pink) and output voltage (blue).

Rail Engineer | Issue 190 | May-Jun 2021

ELECTRIFICATION & POWER simulate the harsh environments and conditions encountered in train-borne operations.

The EC7BW18-ECRT/EDRT series has been passed as compliant for all the tests (for example, low temperature start-up, rapid temperature variation and EMC testing) under all input voltage ranges.

In order to meet the power supply tests, a turnkey product has to be able to provide ‘hold up’ of the output for a period of time after the input supply disappears. This can be done simply by adding capacitance at the input side. However, the transient characteristic of a capacitor will cause higher inrush currents at the input side during switch-on. If there is no action to restrain the inrush current, it can result in a voltage drop at the front-end of the converter or trigger the overcurrent protection of the input circuitry, leading to no output from the converter.

Using its design expertise, Cincon has integrated a built-in active inrush current limiter which has higher efficiency performance with less impact from the ambient temperature when compared to a passive inrush current limiter.

Supply interruption In railway power systems, it is common to see the input supply voltage experience short-term fluctuations due to disturbances within the generator, battery or pantograph system. These can also cause short periods of open circuit or short circuit at the input. EN50155 power supply tests simulate the interruptions of voltage supply and supply changeover, and are categorised into five classes: (Interruptions of voltage supply) » Class S1 - no voltage interruption; no performance criterion is requested, but the equipment continues to operate as specified after the voltage interruption » Class S2 - interruption time 10ms » Class S3 - interruption time 20ms.

ENO 50155 Input Voltage Range Nominal Input Voltage (Vin)

Continuous Voltage Range (0.7Vin - 1.25Vin)

0.6Vin (0.1s)

1.4Vin (1s)

24V

16.8 - 30V

14.4V

33.6V

36V

25.2 - 45V

21.6V

50.4

48V

33.6 - 60V

28.8V

67.2V

72V

50.4 - 90V

43.2V

100.8V

96V

67.2 - 120V

57.6V

134.4V

110V

77 - 137.5V

66V

154V

Fluctuation Voltage Range

Supply voltages seen across the industry.

(Supply change-over) » Class C1 - at 0.6Vin during 100ms, without interruptions » Class C2 - during a supply break of 30ms.

In order to meet the requirements of Classes S2, S3 and C2, additional capacitance is required at the input side of the DC-DC converter. When the input voltage is lower, the required capacitance value will be higher; conversely when the input voltage is higher, the working voltage of the capacitors also needs to be higher. The EC7BW18-ECRT/EDRT has a hold-up circuit which meets the requirements of S2 (limit @24V <14W), S3 (limit @24V <10W) and C2 (limit @48V <15W).

To protect against misuse and over-stressed operation, the EC7BW18-ECRT/EDRT modules feature reverse-polarity protection, over-temperature protection (unit switches off when the case temperature exceeds 106 degrees), over-current protection (short circuit and overload), input under-voltage protection (prevents very high input current at low Vin) and output over-voltage protection (secondary protection against an internal feedback failure).

John Stone is the Sales Director for Relec Electronics.

180

Actual hold up time vs output power for different traction input voltages of the converter.

150

HOLD UP TIME (ms)

120

90 110Vin 96Vin

60 72Vin 48Vin

30

0

24Vin

2

4

6

8

10

12

14

16

18

20

OUTPUT POWER (W)

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VINNY O'HOLLORAN

ARQ renews focus on

decarbonisation D

ecarbonisation will be a significant focus for the rail industry over the next 30 years as the UK Government aims to remove all diesel-only trains by 2040, with a legally binding commitment to net-zero carbon by 2050. The railway has recognised that, collectively, we must do more to be part of the solution to climate change.

Network Rail estimates that to decarbonise our rail network completely, 13,000 single track kilometres will need to be electrified by 2050 - approximately 450 kilometres every year - to achieve net-zero; however, it has been identified that only 251 kilometres was electrified from 2019-2020.

To help Network Rail deliver these targets, a new collaborative partnership comprising three leading rail companies within the Renew Holdings Group - has been launched.

AmcoGiffen, REL (Rail Electrification Limited) and QTS together form ARQ - a truly integrated self-delivery model for the UK rail network as it moves closer to achieving these electrification and decarbonisation targets. ARQ will play its part in meeting the challenges set to industry by Network Rail in response to the decarbonisation agenda.

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Coming together Individually, each of the businesses has been providing expert services in their respective disciplines to enable electrification programmes across the country throughout Control Periods 5 and 6. By coming together as a unique family, the ARQ partnership will offer an unprecedented inhouse delivery model covering the full range of railway engineering services required for future electrification schemes.

Andries Liebenberg is the Executive Director responsible for Renew Holdings’ rail activities. He said: “The Department for Transport, Transport Scotland and Transport for Wales - through Network Rail - have set very demanding targets for the industry. One of the key challenges is that of affordability.

It is clear that the rate of cost increase on typical electrification projects is no longer sustainable.

In addition, development lifecycles are getting longer while not always delivering the desired outcomes.

“ARQ has the ambition to be an integral part of the solution and the future of decarbonisation of the UK rail network.

ELECTRIFICATION & POWER “This is a partnership that is ideally structured to meet the targets which have been set to the industry by Network Rail. ARQ’s significant differentiator is that it will work in partnership as a unified family of companies, each bringing their unique skills and self-delivering the broad scope of what makes up any rail system.”

All bases covered ARQ offers a complete delivery model with a flat structure and reporting lines, with directly employed specialist teams, supported by an extensive plant fleet. Through this, it has the ability to reduce or remove the often-complex contracting models which can add unnecessary layers of cost and risk to any programme.

It will create a more collaborative working environment, with all parties aspiring to achieving the same common goal which, when complemented with early involvement from project inception, will optimise disciplines integration, remove unnecessary job role duplications and promote innovation. Workforce safety maturity will also be reinforced through continuity of safety behaviours, whether individuals are working through the ARQ partnership or their respective subsidiary.

ARQ is already embracing Project SPEED, applying it to schemes currently in development and delivery. This distinct, agile structure and direct delivery model has been well received, with early signs proving to be very positive.

Commitment to invest This exciting new partnership is led by Vinny O’Holloran who joins from Costain Group where he was Project Director within its rail division for six years. Working on projects including Queen Street Station and Stirling-DunblaneAlloa, he brings considerable experience to this newly created role as director, responsible for implementing strategy at ARQ. Vinny commented: “Joining ARQ is a real highlight for me and I was immediately struck by the investment that has already been made.

It demonstrates the commitment that all three businesses - and Renew Holdings - have to making

this venture stand out from the crowd. It is obvious that they have listened to what the customer has said and carefully crafted a strategy which I very much look forward to executing.

“The role will allow me to have independent control over the activity of ARQ, ensuring consistency throughout. It also gives the customer the confidence that they have an accountable individual who is instantly able to influence a programme, with direct access to those who are delivering the works.

“At ARQ we understand that electrification is a significant contributor in meeting Network Rail’s decarbonisation commitments and that things have to change to drive efficiency. We want to be part of this change; to help drive it forward.

We already have the skills within each business to do this and the ability to supplement the skills and knowledge gap in the industry. I am excited by our existing large in-house training facility and plans to expand which will enable us to further invest in training and develop sustainable skills for the future.

“By working together, we bring every element required for what is a rail system under one accountable, collaborative partnership.”

ARQ is also committed to continuing innovation both on and off track. Vinny added: “We are very conscious of the fact that possession time on the railway is at a premium, so we will ensure that we maximise access by continued investment into bespoke rail plant, but also to explore further innovation in the design and build process. We must be able to accurately design in a virtual world, build (where we can) off the railway and then use the access time efficiently, ensuring minimal disruption for the travelling public and maximise productivity.”

ARQ is currently in talks with key stakeholders to look at ways in which it can help to support upcoming electrification projects across the network. www.arqrail.com

Rail Engineer | Issue 190 | May-Jun 2021

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FEATURE

CLIVE KESSELL

Underground PROVIDING 4G RADIO ON LONDON

R

eaders with longer memories will recall that when mobile telephony expanded in a big way during the mid-1980s, voice calling was the all-important factor. Being able to speak with others away from the home and office environment was a big step forward and the 1G analogue networks (Cellnet and Vodafone) took off exponentially. Radio masts appeared everywhere and coverage in excess of 90% was soon available. For the more difficult locations such as basements, sunken roads and especially tunnels, people just accepted that they would be unable to speak until they emerged into a more-open environment.

For many passengers, it is no longer acceptable to be out-of-range.

Starting with the digital 2G network and now advancing rapidly to 5G, data has overtaken voice as the more important connection with messaging, social media, video plus many business functions - finance, banking, ticketing, shopping and such like - all being demanded at the press of a button. No longer is it acceptable to be out-of-range, especially in busy urban areas.

For underground railways and many metros, this represents a considerable challenge as provision for public mobile radio usage in the early days was not considered important enough to justify the costs involved. Most railways of this type did invest in radio systems underground for operational and safety purposes, but the infrastructure - often with extensive radiating cable provision - was not designed to accommodate public radio networks.

The pressure is now on to change this and a talk given recently to the London & SE section of the IRSE looked at the challenges involved both from a technical and commercial aspect. The talk also considered the longer-term consequences of changes to radio technology, both internal to railway operations and the wider public.

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The Jubilee Line trial Setting the scene, Haider Gillani, who is the principal engineer for the Jubilee Line pilot project, and Dimitris Kaltakis, the senior radio engineer at TfL, outlined the objectives and scope of the project. The overall aim is to: » implement the London Mayor’s strategy for public experience » gain insight into customer radio usage » increase knowledge of 4G operation » trial cellular use on the Underground, including exploring radio use for other applications such as mission-critical messaging.

PHOTO: WILLIAM87

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The architecture of the system includes a ‘basestation hotel’ from which all the distribution and aggregation is carried out, a Cat 5 structured cable network around all the station walkways to feed the multitude of antennae and the radiating cable containment within the tunnels. The latter are in metal trays either at the tunnel sides or sometimes in the roof.

Between 50 and 100 engineers were engaged in the installation and testing during engineering hours, taking place over several weeks. It must be remembered that the Jubilee Line is a deeplevel tube and this section - whilst relatively new as it only opened at the time of the millennium

PHOTO: WILLIAM87

PHOTO: STEVE KEIRETSU

The chosen section of route has been the Jubilee Line eastwards from Westminster for eight stations, including the twin running tunnels. This is a busy section serving both Waterloo and London Bridge stations. The logistics for the infrastructure requirements were considerable: » 32km of radiating cable with distributed antennae at stations » two radiating cables required in each tunnel, with basestations feeding about 1km in each direction » 16km of fibre cable » 252 low-power basestations for stations » 76 high-power basestations for the tunnels and platform areas » some radio repeaters in the tunnels where basestation accommodation was problematic.

and thus has slightly larger tunnels than earlier lines - is still very limited for space in the actual running tunnels.

Results so far and challenges The pilot is to run for 24 months, but is likely to continue in service beyond that time. All four of the MNOs (Mobile Network Operators - EE, Vodafone, Three and O2) have their system included in the trial - some on one cable, some on the other; as such, all mobile users can gain access.

Since commissioning, which took place just before the first Covid lockdown last year, performance and usage has been encouraging.

By October, a reliability of 99.98% has been achieved and 85,000GB of data exchanged.

The average person uses around 30Mb, with around 150Mbps cell throughput in station areas and 70Mbps in the tunnels. A clear indication of success emerges, even though ridership was reduced as a result of the pandemic.

Around 85,000GB of data was exchanged between March-October last year.

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FEATURE Securing space for midtunnel equipment has been a real challenge.

Because of the environment, fire safety is vitally important and the LU standards are strict. This meant installing equipment and cabling in fireproof enclosures. Where mid-tunnel equipment was required, obtaining an enclosure within the available space envelope has been a real challenge.

Some gaps in the radiating cable coverage were found and performance has been optimised since the trial started. The basestation ‘hotel’ is duplicated into two different rooms, but the heat generated underground was found to be a problem.

The manufacturers of MNO equipment will need to recognise the importance of fire safety provision and will be required to make variants available to the standard product.

London Underground has other systems in the tunnel where interference might have been experienced. The principal concern was the LU CONNECT network provided by Thales in the 1990s to replace all existing transmission and radio systems with a fibre bearer, digital transmission and a TETRA-based operational radio network. To safeguard its integrity, the initial stance was to have a separation of 600mm between the 4G equipment and the CONNECT infrastructure. After some tests with Thales, a smaller distance was negotiated and even at 15mm, no interference was found. The Jubilee Line operates with the Thales Seltrac CBTC (Communications-Based Train Control) system and, again, testing had to be carried out to ensure no interference.

Exploring future radio predictions Metros typically have not used GSM-R technology for their track-totrain communication requirements, with many - including LU - opting for TETRA. Haider Gillani indicated that having separate technology for metros in the future may not make economic sense. LU is aware that the move to standardise on the FRMCS (Future Rail Mobile Communication System) being developed by the UIC as a replacement for GSM-R may well be applicable.

With functionality due to be completed in 2022 and products available from 2024/5, pilot systems can expect to be deployed soon after that date. A key question will be the availability of dedicated spectrum, but indications are that 5.6MHz of bandwidth in the 900MHz band and 10MHz of bandwidth in the 1900MHz band could become available for rail purposes, although the latter is already in use by the EE mobile operator.

PHOTO: GARY WINFIELD

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Having a single system for all purposes is a projected aim, but assurance on bearer agility, cyber security, spectrum availability and interoperability would need to be proven. The positive view is that applications could go right to the top of the safety-critical curve, including automation of trains, which has implications for the modernisation of rolling stock.

Deployment of such a system is already planned in Asia, notably Hong Kong and elsewhere in China, Seoul and India. In Europe, a full-scale trial took place on the Paris Metro Line 14 in 2016 over 3km of route using a private LTE (Long-Term Evolution) provider in the 2.6GHz band. This was integrated to include the provision of CBTC, CCTV and Passenger Information services. Other rail operators in America, Australia, Mexico, Canada and Brazil are all considering service convergence onto a single communications/radio network.

Emergency service provision Providing radio coverage underground for the fire, police and ambulance services has to be considered in all of this. The Airwave TETRA system created following the King’s Cross fire and introduced from 2006 only really achieved connectivity between police forces in London. It was implemented on the CONNECT backbone and is now being replaced.

A new Emergency Services Network (ESN) in conjunction with the Home Office is being trialled by Frequentis, an Austrian company well known in the UK for radio system provision associated with air traffic control, rail and police networks.

The new network will interface with the Airwave system until such time as full changeover has taken place; it will also cover the ambulance service. The design is a LTE network, built to mission-critical 3GPP standards, and clearly there are opportunities for integration with any 4G network that LU progresses.

Piccadilly Line implications For the forthcoming Piccadilly Line upgrade, the lessons from the 4G trial are being carefully studied, so says Robert Frith, the Head of Engineering for the Piccadilly Line project. Initially, the upgrade will be the purchase of 94 new trains with the intention of achieving a 27 trains per hour (tph) service in the peak, but using the existing signalling. More significantly, a second phase will see the

line being equipped with CBTC to give up to 36 tph, a single new control centre, 145km of digital signalling and an additional 15 trains. Details for the project’s engineering have yet to be firmed up, but with the possibility of having a 4G/5G bearer in place, consideration is being given as to whether this could support all the necessary requirements, including missioncritical services.

For this to be feasible, it would be necessary for the communication networks to be separated contractually from the signalling system. Both underground and open-air sections of line would need to be covered. LU is understandably cautious and would need to be assured that a 4G LTE network that they might not fully control would be suitable as the prime communications bearer.

Obtaining a system safety case is viewed as a challenge. The alternative would be to employ it as a secondary mode and use for:

» live rolling stock and infrastructure diagnostics » the potential to combine with UWB (Ultra Wide Band) technology » facilitation of CCTV, passenger information and line control comms.

PHOTO: MATT BUCK

FEATURE

A move towards greater industry standardisation and modularisation of the proposed signalling assets would be welcome and could influence the decision.

In summary The need to provide reliable data communication to the public is seen as essential and extending the trial on the Jubilee Line to all of London Underground will become policy. Whether a common single bearer will be a practical proposition remains to be decided, given the safety implications of rail operations.

The migration to FRMCS will be a possibility once this becomes an international standard from

2025. Alignment with signalling renewals will be a consideration to take advantage of the bandwidth availability from a 4G network. In time, the CONNECT network will migrate to the new 4G network.

There are some fascinating options for LU to be decided in the next 3-4 years, but it is good that serious thought is being given to the different radio requirements.

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ALL PHOTOS: PETER ALVEY

BOB WRIGHT

IN SE ARCH OF

hidden shafts Rail Engineer | Issue 190 | May-Jun 2021

FEATURE

S

hugborough Tunnel is located between Stafford and Rugeley in Staffordshire, on the edge of Cannock Chase. It takes the West Coast Main Line beneath the National Trust’s Shugborough estate. Built in 1846-47 by the Trent Valley Railway, it is 710m in length and aligned on a 1.5km radius. The tunnel featured in Rail Engineer (Issue 100, February 2013) when the track was relaid and lowered over Christmas 2012.

In common with most 19th century tunnels of any considerable length, its temporary works included shafts sunk along its alignment to enable excavation on multiple fronts. These were all unlined, passing through the Triassic pebble conglomerates and sandstone of the Kidderminster Formation. On completion, they were capped near the top with timber baulks and decking.

The shafts have deteriorated over the 170 years following construction and slight surface settlement had been identified at some, resulting in them being fenced off for safety reasons.

Network Rail made this one of their priority schemes, investing heavily to remove any risk of a collapse of debris into the tunnel. As part of its programme to deal with hidden shafts, the company engaged consultants COWI to locate and investigate the shafts; thereafter a solution was designed to secure and stabilise them, making the tunnel safe for future generations.

Construction and as-built records were patchy and inconclusive. However, COWI was able to use these desktop studies - together with the depressions at ground level and indications from brickwork jointing in the crown - to identify eight shafts. At each one, trial drilling and endoscopes were used for verification and inspection purposes. Seven shafts were soon confirmed, but the last one proved elusive and was only finally tracked down in early 2021, eight months after construction works started on site.

The shafts - up to 30m in depth - were found to be in good condition, but not uniform in size, varying in diameter between 1.8m and 3m.

During test drilling of the tunnel lining, a void was identified between the brickwork and rock.

COWI’s solution was for a project to drill and grout each shaft, and infill the lining void. The contract was awarded to Story Contracting’s Rail division in 2019.

By coincidence, Geobear gave a CPD (Continuing Professional Development) talk to Story Contracting and it was quickly identified that the company’s closed-cell polymer grouts could provide the solution, being lightweight and fast curing, offering controllable spread and not water-based.

During early contractor involvement, Geobear worked with COWI and Story Contracting to develop a solution for Shugborough Tunnel’s problems. There are no formal codes of practice or design codes covering these products, but Geobear was able to share its 40-year experience and technical knowledge to provide COWI with confidence in the product and proposed application.

The agreed solution involved the use of a dense geopolymer to fill the void around the lining beneath each shaft and the first 1m above the shaft base. Lightweight geopolymer would be used to mass fill the remainder.

Grout being injected behind the tunnel lining.

Filling the voids An early proposed solution was to use cementitious grouts behind the tunnel lining and water-based polymer grouts for the shaft infill.

Cementitious grouts are relatively dense and the temporary loading of wet grout on the lining could have resulted in structural damage. Both grout types - being water-based - also bring the problems of disposal and water leakage through the brickwork, potentially contaminating the ballast or drainage.

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Drilling a hole for grouting at the high haunch.

Global ground engineering

Stabilising the shafts

The Geobear company, formerly Uretek, was the inventor and pioneer of geopolymer technology that provides advanced and accurate systems for floor and foundation relevelling, ground stabilisation, as well as void filling and water sealing.

The controllability of geopolymer injection and its rapid curing - just 10 minutes - makes it very suitable for railway works in short possessions and has been used by its 70-strong UK workforce to relevel and support slab track in depots and on the Midland Main Line near Kentish Town. It was also trialled in Network Rail’s Upholland Tunnel in 2020.

The firm’s polymer materials are well proven, with over 200,000 successful projects in 40 years.

Richard Holmes, Geobear’s Managing Director for commercial and infrastructure projects, explained to Rail Engineer that the project began on site in May 2020 and delivery was planned in 27 ‘Rules of the Route’ Saturday night possessions of 8½ hours’ duration, but each effectively offering only five working hours.

The track access point was close by, just 300m west of the tunnel. All Geobear’s plant and equipment was contained with two 20-foot shipping containers, loaded onto rail trailers by telehandler and hauled into the tunnel using road-rail excavators. Work access was provided by two MEWPs (Mobile Elevating Work Platforms). Access to the shaft-top locations - across National Trust land - was established using aluminium trackway and work platforms to avoid damage.

The works were delivered in three stages at each shaft. Firstly, the void behind the brick lining was grouted 5m either side of the shaft, through a grid of holes at 2m centres longitudinally and 1m transversely. In the crown, the works were hampered by overhead line equipment, but works were completed around these without diversion. Around the perimeter of the area, holes were at 500mm centres. These were grouted first, using a dense geopolymer, to provide a bulkhead against which the subsequent grout would be injected. Grouting was restricted to 4 bar injection pressure to reduce any risk of damage to the lining.

Secondly, four grout holes were drilled through the lining into the shaft and further groutinjected to seal the base of the shaft, binding any debris sitting on the lining. A single 60mm diameter hole was drilled to inject a lightweight geopolymer higher into the shaft, filling the first 4m to form a plug.

GEOBEAR LIGHT GEOPOLYMER GEOBEAR DENSE GEOPOLYMER RESIN PLUG 1m ABOVE LINING

GEOBEAR DENSE GEOPOLYMER POLYMER RESIN

WEEP HOLE

Rail Engineer | Issue 190 | May-Jun 2021

1x 60mm DIAMETER CORE HOLE FOR INITIAL 4m OF INFILL 4x 16mm DIAMETER CORE HOLES FOR RESIN PLUG

28mm DIAMETER CORE HOLES FOR RESIN HOSE AT 1m CENTRES

WEEP HOLE

FEATURE

Equipment was brought into the tunnel in a shipping container.

Finally, from surface level - with the machine positioned well back from the shaft - Geobear drilled at 45º into the shaft tops, entering at up to 6m depth. This hole was then used to inject more grout in a single pour to completely fill the shafts. Up to 80m3 was needed per shaft.

During drilling for the lining grout holes, it was discovered that the voiding behind the lining greatly exceeded the anticipated 50mm average, with some being up to 500mm; the average was 135mm. As a result, Network Rail extended the contract to allow for this additional volume of grouting and, ultimately, 48 possessions were required rather than the planned 27. The eighth shaft was finally proven late in the contract and this was infilled within the extended contract period, with works completed by June 2021.

This unusual project was delivered very successfully, in part as a result of the close collaboration between Network Rail, COWI, Story Contracting and Geobear. It has proven the suitability of closed-cell geopolymers and further opportunities are foreseen.

A container is loaded onto a trailer at the access point.

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CONDUIT

SIDE

T H E

TRACK

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Rail Engineer | Issue 190 | May-Jun 2021

D

ata connectivity is vital for all aspects of society and industry, and is becoming increasingly important for railway operations.

Signalling, electrification control, fixed and radio communications: all rely on cables running alongside the railway. However, the integrity and value of these cables is only as good as the protection offered by the lineside cable route. Often overlooked or taken for granted, it is vital for the safe, efficient operation of any railway.

The primary function of any form of cable route is to protect the cables within. Ideally it should provide mechanical protection, so it must be robust and stable, fire and vandal proof, capable of being opened and closed to maintain the cables or run new ones, be cost effective and safe to install, and require minimal maintenance. Cable routes can be constructed from a variety of materials and come in different sizes and shapes. Transition modules may be required along with ‘T’ junctions, bends and joint bays.

All these requirements are not easy to achieve and can conflict. An assortment of route types have been used over the years and the search for an ideal cable route is never ending.

An evolutionary approach The first types of cable routes were open copper wires raised on wooden poles. With the introduction of overhead electrification, signalling and telecoms cables were run at ground level in some form of cable containment. On the majority of non-electrified lines or those with conductor rails, cables are now provided at ground or sub-surface level. Wooden cable routes were used initially, but these soon rotted and have not been used for many years. Asbestos cable routes mounted on posts were then provided, but these didn’t offer much mechanical protection and introduced a health and safety risk.

One of the more successful systems was concrete ground-level troughing, generally known as GLT. With detachable lids, this has been used for many years and is supplied in various

PERMANENT WAY & LINESIDE ASSETS

sizes, generally in 1m lengths. It provides reasonable mechanical strength, although the natural walkway it forms encourages its use as a lineside pathway. It was not designed for this purpose and a misaligned lid can easily cause injury if walked on.

The weight of concrete troughing gives it reasonable stability, but makes it difficult to handle manually and its installation can require extensive possessions for off-loading. Deeper and higher ballast shoulders have, in places, transformed the troughing into ballast retaining walls or totally burying it. Any displaced alignment may put strain on the cables within and make it even more hazardous to walk on. While concrete troughing is reasonably inexpensive for the protection achieved, it is costly to install with manual labour and requires frequent replacement of damaged lids.

In the 1960s, to obviate many of the disadvantages of the precast concrete route whilst retaining its inherent advantages, a continuous slip-formed concrete route was trialled. A train with an earth plough formed a trench alongside the track. Concrete was then discharged from the train into the trench, after which the train made a further pass with a plough to create a trough in the concrete. Once dry, precast concrete lids were off-loaded.

This method removed much of the manual labour involved in construction, but required a site with soil suitable for the earth plough, precise control of the concrete mix consistency, accurate rate of discharge into the trench and consistent train speed. It was also found that an unplanned thunderstorm turned a near-finished length of route into a disaster area! The trial was abandoned.

right situation the method has some advantages, but large cables can present problems as certain types of soil do not consolidate and can leave a damaged embankment or cess. The method requires careful planning and preparation, with robust buried service checks prior to the cablelaying. It only takes one old signal base to break the plough and seriously delay the programme.

In locations with sharp stones, additional cable protection is required with sheathing or sand backfill. However, ploughing small fibre cable ducts could be an answer for the future. We’ll come back to that later.

PAUL DARLINGTON

Plastic routes Over the years, various sorts of plastic cable routes have been trialled for lineside cable containment. Unfortunately, they have generally not provided the required mechanical strength, especially when faced with ballast alongside the route. Plastic also contracts and expands as the temperature varies and it is not easy to incorporate adequate expansion mechanisms.

Buried cables In areas of theft risk, cables can be buried directly in the ground at a depth providing adequate protection. Installation is generally required immediately after the trench has been dug as heavy rain can collapse it prior to backfilling. Alternatively, a duct system can be buried prior to the cables being pulled through or, in the case of fibre cables, blown through with compressed air.

Any buried route is expensive to install particularly with manual labour - and may require rail-mounted machinery for excavation. Gaining access to the cables requires careful selection of the breakout point locations, together with jointing bays. The chosen cable must be suitable for direct burial and it is not easy to subsequently connect into the cable route.

Another method of direct burial is by utilising a rail or vehicle-mounted mole plough. This is a hydraulically controlled plough blade, with the cables fed through conduits in the blade. In the

Railtrack had some success installing a 100mm plastic surface pipe with thermal expansion mitigation which was staked into the ground every few metres. This provided protection to a telecoms cable running between signal boxes on rural routes and is still in use 25 years later. This wasn’t suitable for larger volumes of cables on main lines and it wasn’t easy to provide regular cable breakout points.

Recycled polymer Over the last ten years, cable routes made from 100% recycled polymers - such as polypropylene - have been introduced which offer similar high strength and impact resistance to traditional concrete, but are approximately five times lighter for the same size and far easier to cut. A further enhancement - building on

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PERMANENT WAY & LINESIDE ASSETS PHOTO: FOUR BY THREE

the problem of walking on narrow concrete lids was the introduction of a combined cable route and safe walkway, also made from recycled polymer. Two routes with the equivalent capacity of two concrete troughs were located under a 700mm wide non-slip surface. The lids were constructed so that cables could be laid with half the route open. Fixings were also provided for a removable handrail and the ability to secure the lids to the troughing to deter cable theft.

Following removal of the lids for installation purposes, there have been reports of a route’s sidewalls being deflected inwards due to the weight of the adjacent ballast, preventing the lids being replaced correctly. This caused the lids’ outer edges to be unsupported and move unexpectedly under the weight of footfall, thus creating a trip hazard.

This illustrates the need for maintenance of all cable routes and, in this case, to ensure the lids were securely attached to the sidewalls and not displaced from their correct positions.

Elevated troughing In cuttings susceptible to slippage, the toe cannot be excavated to accommodate a trough or buried route, so an elevated troughing route may be required, mounted on posts which only interfere with the soil formation at a minimal number of points. As well as early use of asbestos, elevated troughing has been constructed from a variety of materials over the years including timber, cement, glass-reinforced plastic, metal, recycled polymer and glass-fibre reinforced concrete (GRC).

Rail Engineer | Issue 190 | May-Jun 2021

Many elevated routes lose their alignment during their lifetime due to movement in the soil foundation and are particularly prone to damage as they form an obstruction to track work and make natural seats.

Nevertheless, elevated GRC routes have, in particular, been widely used and are easy to transport and install.

Theft and vandalism Vandalism and theft of copper cables have produced particular problems. Concrete routes may require lids to be fixed with metal clips or epoxy adhesive to deter theft. In high-risk areas, cables have been sealed into GLT with concrete, but this is generally not recommended as cement can harm some cable sheath types and filling the trough route with concrete makes it unusable for other cables. It is also expensive and labour intensive.

Putting blobs of concrete in the trough is not good either as thieves have been known to cut and steal the intervening length, making it difficult to run a replacement cable.

Buried routes are quite effective as a deterrent if sufficient depth is maintained and the soil is well consolidated, although it has proved necessary in some locations to anchor the cables to prevent them being pulled from the ground using road vehicles.

Fibre cables When the national fixed telecoms network was deployed by Network Rail, a heavily armoured variant of the normal armoured optical fibre was chosen to deploy without any cable route. This was known as Double-Insulated Super

UNIQUE T T S C A B LE TRO UG H WALK WAY SYSTE M FOR P OW ER & COMMUNIC ATIONS The TTS anti-slip Walkway system is designed to provide a hard wearing and safe surface for troughing routes where a low to zero maintenance walkway is required. The unique anti-slip Bimagrip® surface has been rigorously tested and outperforms other walkway systems.

• Made from a 100% recycled polymer, walkway units can easily be carried by one person.

• Handrail attachments accommodate a composite safety rail.

• Bend units provide greater flexibility in safely navigating around obstacles.

• Integrated T-junctions allow routes to branch off to locations, maintaining the anti-slip route.

• Lids can be independently lifted allowing access to cables.

• Lids can be locked to protect against cable theft and vandalism.

• Bases have a built-in security system allowing for the use of cable ties to further protect against cable theft.

The TTS team has established an unrivalled depth of knowledge and experience, enabling us to provide tailored cable trough solutions to major rail and civil engineering projects.

Whatever your cable troughing challenges, we work with you to overcome them.

PHONE:

01302 343 633

·

EMAIL:

info@ttsrail.co.uk

·

WEBSITE:

ttsrail.co.uk

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PERMANENT WAY & LINESIDE ASSETS

Armoured Cable or DI-SAC which was approved for use where only optical fibre cables were required.

DI-SAC comprised 24 single-mode optical fibres divided equally into two stainless steel tubes, helically wound around a solid aluminium former, encased inside a mediumdensity polyethylene inner sheath and thick steel-wire armour, with a green oversheath of fire-retardant ethylene vinyl acetate.

In walking areas and those prone to vandalism, DI-SAC was scratch-buried so it did not protrude above ground level.

Nominally, it was secured into the ground every 40m, but this distance varied to prevent the DI-SAC being pulled onto the track. Its use without a cable route was questioned by many in the industry, but it saved the national fibre project several hundred million pounds. The cable was specially made in high volumes and is no longer commercially available.

Blown fibre Fibre optic technology has now become the norm for telecoms transmission as it provides huge data transmission capability, solves the problem of inductive interference with long distance copper cables and has no theft value.

Fibre cables were traditionally installed in concrete trough routes in lengths of up to 2km.

Selected fibres would be broken out to connect to the digital transmission equipment. Originally, such equipment would use local copper cable tails to provide connections to equipment such as telephones, data terminals, radio base stations and signalling interlockings.

Rail Engineer | Issue 190 | May-Jun 2021

With the introduction of all-IP (internet protocol) networks, fibre-borne digital signals right to the end device are now becoming the norm which has led to the concept of ‘blown fibre’ as an option.

This involves a composite material pipe incorporating several ducts of different sizes being installed either on the surface or buried.

Bundles of fibres can then be blown into the duct using compressed air and further bundles can be similarly installed into different tubes at a later date, as required.

One drawback of normal routes is that new cables tend to be laid on top of existing cables in the route. When new signalling or telecom systems are brought into use, the redundant cabling remains in place and the trough becomes over-full. With fibre blowing it is relatively easy to remove fibre bundles and replace them should this be required.

Conventional troughing routes and copper cables are far larger than the blown-fibre solution and more expensive to install.

As the blown-fibre duct can be coiled and directly ploughed into the ground using smaller machinery, it may be more cost effective and flexible than traditional buried routes. Blown fibre has been trialled in Scotland for lineside installation, but is yet to receive national approval due to concerns with route expansion. At the very least, blown fibre may be a good option for fibre in buildings and stations.

So, the search for the ideal cable route continues in order to maintain the integrity and value of the vital cables which support a safe, efficient railway.

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Railway Industry Supplier Qualification Scheme

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PAUL DARLINGTON

A model for

containment S

chneider Electric is a major multi-national company, operating in a wide range of sectors including energy management, industrial automation and control. The company’s extensive product includes an impressive range of Glass Reinforced Polymer (GRP) elevated cable troughing and accessories which are designed and manufactured in the UK. Operating in more than 100 countries and employing over 135,000 people, Schneider Electric prides itself with its extensive research and development capability, and it invests 5% of its annual revenue in R&D. It also holds 20,000 patents worldwide, demonstrating its engineering creativity. In the UK, the company operates from a number of sites, providing products for automation and control, electrical distribution, building management, critical power and energy automation.

GRP elevated cable troughing is an especially useful containment system for rail. Ground Level Troughing (GLT) is often used in signalling and telecoms schemes for the cable connections to lineside equipment such as points, train detection, signals and radio sites. However, in many places, GLT cannot be used due to the ground profile and steep embankments and cuttings. GRP is an ideal alternative for such locations and it is also essential for large current-carrying power cables.

A MitaTM GRP ladder beam support fixed to a tunnel wall.

Rail Engineer | Issue 190 | May-Jun 2021

High quality manufacture The MitaTM GRP is produced by pultrusion technology. This uses a combination of unidirectional and cross-strand glass mat which is resin-impregnated and pulled through a hot die to produce a very solid, structurally sound profile with excellent mechanical rigidity. Unlike some other troughing systems, MitaTM GRP does not contract or expand with heat causing the troughing route to distort. It is produced with a high quality of manufacture and modified by the use of additives to the resin, and with protection from ultra-violet light. The product is produced in either 3m or 6m lengths for easy transportation and installation.

MitaTM GRP is 70% lighter than steel and 90 times lighter than concrete; it is also corrosion resistant. It does not conduct heat and has excellent durability against adverse weather conditions. The product offers excellent UV stability resulting in a cost-effective long-term solution.

PERMANENT WAY & LINESIDE ASSETS The MitaTM GRP is provided in a wide range of trays, troughing and ladders which can support any type of cable - especially power and fibre cables which require a gentle bending radius. Unlike some competitors’ systems, MitaTM elevated troughing is provided with GRP support posts to increase its durability. The troughing lids clip securely in place, providing cable theft protection. Further security can easily be added by installing stainless steel bands around the elevated route.

Network Rail approval The MitaTM GRP elevated cable route has been fully approved by Network Rail under Certificate of Acceptance PA05/00442 issued in 2015 for use in locations unsuited to GLT. The Zero Halogen Low Smoke (ZHLS) version has also been approved for use in sub-surface stations and connecting tunnels. Furthermore, the approval applies to a very impressive 42-page list of accessories, including bends, brackets, risers and transition/reducer pieces. Allowing connections to existing GLT cable routes, reducers are important and not always available in other cable containment systems.

“A cheaper, quicker and easier-to-install system that gives a true fit-andforget solution.”

London Underground has successfully used MitaTM GRP troughing. They were concerned that their sensitive signalling equipment was susceptible to contact by flakes of galvanisation from steel support systems and that their DC traction cabling system might create eddy currents within troughing ladders and supports if they were metallic. MitaTM GRP troughing was chosen as it is non-magnetic and has nonconductive properties. The ZHLS version is also a requirement for London Underground’s subsurface locations.

The cable containment system is not just used in rail, but has also been successfully employed in a wide range of industries including data centres, power industries, manufacturing, water treatment, food production, industrial buildings and oil and gas.

single, integrated system. It can be applied from the initial concept design through to detailed design and construction. A user can create an accurate 3D model of the cable troughing route, making it easy to ensure that adequate space and clearances are available in confined locations, and for the detailed design and material requirements to be quickly and easily produced.

MitaTM GRP is a non-hazardous, inert product.

It is lightweight and can be manually handled without difficulty, unlike concrete. In contrast to steel, GRP does not have to be deburred or given edge treatment before fitting, saving time and further reducing labour costs. During installation, any cutting, drilling, bonding and jointing can be easily undertaken and will not give rise to a hazardous situation, with any dust kept to a minimum.

Andrew Sillars, Contractor Specification Engineer, says: “Having supported the specification of Glass Reinforced Polymer cable containment since 2005, I have experienced its unique features such as light weight, long-life durability, no deburring, no earth bonding and many more. All these advantages of GRP Cable Containment support a cheaper, quicker and easier-to-install system that gives a true fit-andforget solution.”

MitaTM GRP troughing in use on the East Coast Main Line.

Sample components of the MitaTM GRP troughing system.

Working with GRP Another particularly useful feature of the MitaTM GRP system is its ability to be integrated with the Bentley Raceway and Cable Management Building Information Modelling (BIM) tool. This provides a complete layout, routing and material estimating function in a

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DAVID SHIRRES

PHOTO: NICOLA COLOMBO

Back to the Future the historic permanent way is here to stay

T

here’s no shortage of articles proclaiming the benefits of Hyperloop and Maglev transportation. Yet such features rarely have any serious engineering analysis. In 2012, Elon Musk published a technical paper proposing his Hyperloop concept of pods in vacuum tubes. In this, he recorded his disappointment that the home of Silicon Valley is building a high-speed railway which he, and others, saw as an outdated technology.

But are they? As shown below, the permanent way has evolved into a modern well-engineered system for guided transport that is hard to beat.

The railway’s long history is certainly no bad thing. Like all modes of transport, railways have been developed from crude beginnings and now benefit from many years of worldwide experience, research and development, which include painful lessons learnt.

Wagonways to steel rails

Fish bellied rails.

From medieval times, wagons in mines have been moved on wooden tracks in mines. In the 17th and 18th centuries, Britain’s various timber wagonways (or waggonways) were

Rail Engineer | Issue 190 | May-Jun 2021

built to carry coal. Possibly the world’s first overground wagonway was the Wollaton Waggonway which opened in 1604 near Nottingham. This was used to haul coal for two miles from Strelley to Wollaton.

Another early wagonway was that between Tranent and Cockenzie in East Lothian, Scotland, which opened in 1722. This supplied coal from the mine at Tranent to the salt pans at Cockenzie, three miles away down an average 1 in 50 gradient which required a substantial embankment to maintain an even grade. The coal was carried on wagons that had a brakeman to control their descent and the empties were returned by horse. The line cost £3,500 - the equivalent to £400,000 today.

With the development of the iron industry in the late 18th century, iron plates with inside flanges replaced the wooden timbers that had to be frequently replaced. However, the accumulation of dirt on the plate rail reduced the load that could be hauled.

William Jessop realised that the solution to this problem was raising the rails. To do so he developed three-foot long fish belly I-section rails which were laid on stone pads to give horses a smooth path between the rails. Their first use was for a three-mile long railway in Loughborough in 1789. This seems to have been the first use of flanged wheels on rails and, if so, was the world’s first railway.

PERMANENT WAY & LINESIDE ASSETS Learning lessons

Material changes

When steam locomotives were first introduced, there were concerns that their wheels would not grip the rails, so some early locomotives had rack and pinion propulsion. However, it was found that the friction between wheel and rail was generally sufficient to haul trains.

What was a problem was the weight of the locomotives, which broke the cast iron rails of the time. It was the introduction of wrought iron rails that enabled steam locomotives to be used on early railways. Originally, these rails were laid on stone pads. However, where the ground was particularly soft, it was found that wooden sleepers were required to spread the load, which became the accepted practice.

The first steel rails were laid in Derby station in 1857. The transition to steel rails was hastened by later developments in steel making. By the late 19th century, the basic configuration of the permanent way had been established and it was carrying heavy loads and passenger trains travelling at speeds approaching 100mph.

Since then, there have been many developments in track manufacture, construction and maintenance, including the introduction of continuously welded rail to eliminate track joints.

As a result, tight geometrical tolerances can be sustained to safely carry frequent 200km/h passenger trains and heavy freight trains.

However, ballasted track is at its technical and economic limit for trains operating at 300km/h, which has high dynamic forces and requires more demanding tolerances. This drove the development of slab track, which was used for 19,000 kilometres of China’s 29,000km highspeed rail network and will be used for HS2.

(Left) Stone block sleepers, repurposed at Linlithgow canal basin.

To prevent track movement, early engineers considered anchoring it in place. However, as speeds and weight increased, it soon became apparent that the best way to carry the railway’s load without damaging the track was to secure it in a layer of stones, to provide the right balance of rigidity and elasticity. It also enabled track geometry to be relatively easily maintained by packing stones under the sleepers.

Switches were also developed from the early days - initially stub switches which had moveable rails cut off squarely at the end to line up with the fixed rails. These were susceptible to impact loads and were progressively replaced by those with switch and stock rails which were developed to carry heavy loads safely at high speeds.

Efficient surface transport In parallel with the development of modern track, rolling stock suspensions and wheelsets have been the subject of a huge worldwide research and development effort to ensure that trains can reliably run smoothly and safely at speeds of up to 225mph or carry freight trains weighing thousands of tonnes.

After these various developments, a railway now offers the most efficient system of surface transport that carries heavy loads and operates at high speeds because:

(Above) Slab track on high-speed line.

(Left) A stub switch.

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Chinese CRH3 high speed train with a maximum operating speed of 380kph.

» Loads are efficiently distributed - the maximum dynamic wheel force of 350kN results in a pressure on the rail head of 2.8kN/mm2 which is progressively reduced through the rails, sleepers and ballast to 0.5N/mm2. Hence, high dynamic loads from high-speed trains and the large axle weights of heavy freight trains can be carried on a relatively narrow formation. » Low resistance to motion - the rolling resistance of steel wheels on steel rails is about 0.1% of the weight of the train, compared with about 1% for car tyres on a road. At speed, aerodynamic resistance becomes the dominant factor. In this respect, close-coupled railway vehicles have lower resistance to motion than the same number of individual vehicles. » High passenger and freight capacity - the ability to couple many vehicles together offers high freight and passenger capacity, despite the need to distance trains for safe separation. A Eurostar train can carry 900 passengers. When completed, HS2 will have capacity for 18 such trains an hour out of London, about 16,000 passengers per hour. A two-lane motorway carries around 4,000 people per hour. » Collecting electricity on the move - as trains are part of a guided system, they receive megawatts of power as it is generated. Electric trains are thus highly efficient and take advantage of the greening of the grid to reduce carbon emissions. » Connectivity - new railways connect into the existing railway network to offer far more journey opportunities than those on the new line.

However, permanent way is expensive, so these benefits can only be realised if there is sufficient traffic.

Rail Engineer | Issue 190 | May-Jun 2021

Hype and reality So, what of Hyperloop? Most of the literature promoting it concerns only the pod and its tube. Yet a transport system has to be much more than this. For example, claims have been made that the tube/pod system is now proven, without any mention of switches. Any serious engineering analysis of all aspects of the Hyperloop system shows that many significant problems have yet to be addressed before it can operate safely. These include switching very high-speed pods between tubes, hyperloop tube expansion, emergency evacuation from inside the vacuum tube and signalling systems.

Readers familiar with the Railways and Other Guided Transport Systems (Safety) Regulations may imagine the task faced by those who wish to obtain authorisation to operate a system that carries people in vacuum tubes for hundreds of miles at speeds of around 750mph.

Even if it were possible to prove the safety integrity of all these aspects, the cost of constructing vacuum tube infrastructure over long distances must be justified. Yet, with its small pods, Hyperloop has a poor passenger capacity, as shown in Elon Musk’s paper which states that it would carry 840 passengers an hour. This is just 5% of HS2 which will have the capacity to carry 16,000 passengers out of London.

PERMANENT WAY & LINESIDE ASSETS

reputable consultancies and received uncritical press coverage. The money this attracts then further adds to their false credibility. Furthermore, various countries have backed proposals to build a hyperloop.

It seems that the hype and attraction of these futuristic proposals transcends engineering realities. The danger is that decision-makers might consider Hyperloop and Maglev to be realistic proposals, to the detriment of proven transport technologies.

The reality is that, over the years since they were first proposed, those promoting Hyperloop and Maglev have yet to demonstrate that they have analysed and satisfactorily addressed all safety, engineering, operational and economic aspects of their systems. It is difficult to see how they ever can.

Hence, a well-engineered modern railway will continue to provide the most Maximum Shinkansen speed (modelled up efficient way to 300mph to indicate monorail resistance) of transporting freight and passengers AERODYNAMIC RESISTANCE where the cost of its ROLLING RESISTANCE infrastructure can be justified. Its permanent way will continue to be just that.

Unlike Hyperloop, Maglev has demonstrated its technical feasibility. Although its electromagnetic levitation eliminates a train’s rolling resistance, this offers no real advantage. At high speeds, rolling resistance is a tiny fraction of the aerodynamic drag and comparable with the energy Maglev needs for its levitation. What Maglev does offer is maximum speeds of around 300mph, compared with 225mph for high-speed rail.

Yet, as with Hyperloop, it has no economic justification. Between London and Manchester, a Maglev offers a time saving of around 15 minutes over HS2 and could never justify the huge infrastructure cost over this distance, especially as it cannot be plugged into the rail network to offer more journey opportunities.

Both these technologies, but particularly Hyperloop, have attracted a large amount of investment, been promoted in reports by 300

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(Above) Engineering analysis of Hyperloop shows many significant problems.

(Inset) The world’s only high-speed Maglev which takes 8 minutes to travel on its 18 miles line to Shanghai Airport Maglev at speeds up to 270mph.

Japanese High-Speed Train: Resistance to Motion.

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PETER HEUBECK

Longer-life crossings B roken rails in plain line track - once a very serious problem - are now much less common. Improved rail manufacturing, the widespread use of heavier 60kg rail and improved defect detection have reduced the number of broken rails from 444 in 2002/3 to 71 in 2019/20. Although one can never be complacent, in broad terms the problem is now managed very effectively. In contrast, cracked and broken crossings in S&C have proved a stubborn problem to solve.

Crossings are subjected to very high impact forces and must be capable of withstanding high traffic loads. Certain worn wheel profiles cause extensive damage. Crossings are not designed to flex and must be adequately supported. For this, the layout must be installed on wellconsolidated ballast and subject to effective regular maintenance to, among other things, prevent voiding underneath bearers. Such voiding greatly increases the stresses on individual elements of an S&C layout, including crossings.

Network Rail and its contractors have worked hard to improve the quality of S&C installation work in recent years. However, with many routes being very heavily used and possession time scarce, there is a risk that S&C layouts are being under-maintained, although reduced train frequencies during the pandemic have given maintenance teams an opportunity to carry out work on junctions which are normally difficult to access.

Driving change For crossings used in CEN 60 layouts, the new NR 60 Mk II design is a big improvement. Compared to CEN 56 layouts, the heavier rail gives added stiffness and the closer bearer spacing - 650mm between centres as opposed to the previous 710mm - gives greater support.

Improved rail pads offer more resilience and under-bearer pads aid ballast engagement. So new NR 60 layouts will be better able to withstand the forces to which they are subjected.

However, the number of new CEN 60 layouts is small and will only increase slowly. The harder and more urgent problem is how to reduce the number of cracked and broken crossings in existing CEN 56 layouts. The obvious beneficial measures of increasing the depth of the crossing or reducing bearer spacing are not possible when replacing a defective crossing in an existing layout. Tricky problems call for clever engineering.

Two factors have previously hindered design development.

The vast library of crossing patterns held by the largest crossing supplier represents a financial incentive to perpetuate existing designs. Secondly, tenders issued by Railtrack and Network Rail have generally concentrated on procuring existing designs more cheaply, rather than developing higher quality, more durable products. So, with the exception of Explosive Depth Hardening as a post-manufacturing treatment, the design of CEN 56 crossings has remained static for a long period.

Network Rail’s track engineers became increasingly concerned at the numbers of crossings cracking or breaking under traffic, despite being correctly manufactured and compliant with the existing standard.

Although traffic levels were increasing and, in some cases, layouts

Rail Engineer | Issue 190 | May-Jun 2021

PERMANENT WAY & LINESIDE ASSETS were perhaps being undermaintained, this clearly wasn’t the whole story. So NR resolved to rewrite standard NR/L2/ TRK/012 with the objective of achieving more resilient and durable crossings. This complex project was undertaken by Bleddyn-James Davies, Network Rail’s Senior S&C Engineer.

Track record voestalpine - the global market leader in S&C and advanced rail manufacturing - is one of three firms supplying crossings to the UK, the others being Progress Rail Services UK and Vossloh. voestalpine began supplying crossings to Railtrack after its entry into the UK S&C market in 1995 when it bought the former BR S&C works at Baileyfield in Edinburgh. voestalpine Turnout Technology UK now operates both Baileyfield and a large finishing and assembly site at Harworth, nine miles south of Doncaster. In addition to its S&C business, the company also has a rail sales office in London as well as a signalling and remote monitoring technology company at Fareham in Hampshire. voestalpine has a long-standing policy of investing heavily in both R&D and product technical support. In addition to being the leading global manufacturer of premium rails, it pioneered tri-metallic crossing welding, hydraulic back drives, advanced POE systems, the use of harder rails in S&C and tilting wagons for modular S&C. Within its Railway Systems group of companies, voestalpine has crossing manufacturing centres in Bilbao in northern Spain and at Zeltweg in Austria. The Zeltweg complex is the second largest S&C manufacturing plant in the world, the largest being in China. Although smaller than Zeltweg, the JEZ plant at Bilbao is still large, with an annual capacity of more than 5,000 crossings. The main foundry, laboratory, designers and management are located

at Llodio near Bilbao, while additional casting capacity, flash butt welding and finishing is at a second site in Arberats-Sillegue, just across the French border.

JEZ have been making S&C since 1926 and the team includes a significant proportion of highly-qualified technical staff in design, production and quality management roles.

After welding and finishing in Arberates-Sillegue, new crossings are despatched to customers in 35 countries throughout Europe, Africa, Asia and the Americas.

Over recent years, voestalpine Turnout Technology UK has strengthened its team and instilled a real quality culture.

The team has established an enviable track record for highquality products, responsiveness to customer requirements and all-round user-friendliness.

A more demanding standard In early 2018, the UK team accompanied Bleddyn-James Davies on the first of several visits to Bilbao to highlight the potential for design improvements to CEN 56 crossings. The senior designers at JEZ gave an extended technical presentation, based on their analysis of existing CEN 56 crossings. They made wide-ranging recommendations for detailed manufacturing and design changes.

The fixed parameters meant that there could be no single ‘magic bullet’, but meticulous analysis of every aspect of

the design and every stage of manufacturing led to a series of potential changes which, collectively, would lead to a much more durable product.

Crossing walls could be thickened and the underside flattened; potential stressinducing features such as sharp edges and radii could be removed, while the process for pouring and cooling the liquid manganese steel could be improved. Advanced modelling of the impact of these changes demonstrated that the fatigue life of the crossing would be at least 20% greater. Given the fixed parameters, this was an excellent result.

Encouraged by this work, Bleddyn-James Davies then proceeded to finalise the new standard, which was issued in March 2019, with a compliance date of September 2019.

Bleddyn’s ambitious approach was to aim high with a very onerous standard. Manufacturers are required to demonstrate how they comply and to risk-assess any aspects with which they cannot comply.

The JEZ team made wideranging recommendations for manufacturing and design changes to existing CEN 56 crossings.

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Since its initial work, the JEZ design team has been through an iterative development process which has led to a mature fifth version of the improved crossing. Increasing numbers of these cost-effective and more durable crossings are being ordered by Network Rail, both to fulfil current orders and increase emergency stocks.

The sales and design teams at voestalpine Turnout Technology UK have been busy liaising with order originators, clarifying the precise characteristics of the crossing required. Some frontline maintenance staff need assistance with the dizzying array of S&C installed in the network. The team at Harworth liaises very closely with JEZ over supply schedules.

It is a credit to both teams that they have managed to increase supply during the end of the Brexit transition period and a global pandemic! In fact, due to hard work in both countries, supplies from JEZ experienced only minor problems with the new post-Brexit customs arrangements and every week more crossings are arriving at Harworth. Here they have their leg ends cut to the required length, and baseplates and spacer blocks fitted as required, prior to despatch to the customer.

In Bilbao, JEZ is busy expanding its stock of expensive, precisely manufactured patterns. It already held patterns for the most commonlyused NR crossings; these have now been modified to reflect the new improved V5 design. A large number of additional patterns are being produced to widen the range of crossings JEZ can cast for the UK market.

Pattern-making is a highly-skilled process.

Patterns were previously made from solid wood but, even with careful storage, these could distort over time. High-quality wood laminate is now preferred. To keep the patterns in the best possible condition, they are stored in a warehouse with both temperature and humidity control. The process of designing new patterns is time-consuming and requires meticulous care, but two new patterns are now being completed every week.

These significant design and service improvements - especially when combined with Network Rail’s plan to hold larger stocks of crossings - will reduce the incidence of crossings failing in traffic and will reduce supply lead times to hard-pressed frontline maintenance staff who have the onerous task of keeping our busy and varied rail network in good condition.

New crossings are despatched to customers in 35 countries throughout Europe, Africa, Asia and the Americas.

Rail Engineer | Issue 190 | May-Jun 2021

HIGH SPEED Innovative System Solutions for Future-Proof Networks

Given the growing environmental awareness and the trend in energy prices, today‘s high speed technology offers huge potential. Speeds of almost 400 km/h and diverging speeds exceeding 200 km/h make stringent demands, but can be mastered safely and comfortably today thanks to the system solutions of voestalpine. From Europe to the Far East, there is hardly a high-speed network without track components from voestalpine.

This is what we call “Performance on Track®”.

voestalpine Railway Systems www.voestalpine.com/railway-systems

FEATURE

R

GET A GRIP

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ail Engineer has been following the activities of the rail industry’s Adhesion Research Group for some time and has reported, amongst other things, on Double Variable Rate Sanders (DVRS) and rail head cleaning, as well as modelling and simulation tools.

The latest event - the ADHERE 2021 webinar series - took place in March and April, and reported progress on these developments as they seek to bring the technologies to market and make the business case for their adoption.

This article covers some of the event highlights, with more to follow in the next issue.

Double Variable Rate Sanders

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Previous tests have demonstrated conclusively that DVRS delivers an effective braking performance even in appalling adhesion conditions; a little sand in the right places really does work wonders. In this session, the speakers explored the benefit to be gained by exploiting DVRS and the business case for retrofitting to existing trains.

Peter Watson, Ricardo Rail, described the analysis of data from six specially equipped Class 323 units - two fitted with DVRS - deployed on the Birmingham Cross City route which is notorious for autumn leaf-fall performance

issues. This line has 22 to 25 stops, depending on route, with a typical run time of 150s between stops for a typical distance of 2.3km.

Each station-to-station run comprises four phases: dwell time, acceleration to maximum speed, coasting and brake to stop at the next station.

Peter said that the units were monitored during the period June to December 2019 to provide summer and autumn data, allowing detailed analysis of each of those four phases for every journey.

He highlighted a typical inter-station run to illustrate the principle and then showed superimposed speed distance curves for each inter-station run - both northbound and southbound - coloured blue for summer and red for autumn. These showed variable driving styles. In general, the red traces were lower and more variable than the blue traces indicating that autumn performance was generally slower than summer.

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DVRS Business Case This quantified impact on performance is vital in developing the business case for retrofitting DVRS which was presented by Iain Flynn, Rail Delivery Group, using this and other industry data.

Iain said that there has been a fairly consistent drop in the Public Performance Measure (PPM) of just over 5% during each of the last ten autumns.

This is because trains cannot consistently deliver a brake rate of 0.6m/s2 - the brake rate assumed in the timetable. Professional driving policies can also lead to train braking at a lower rate than the available adhesion would permit. This costs the industry approximately £100 million per annum, with the overall disbenefit to society estimated at circa £300 million. The business case proposition was “DVRS would guarantee 0.6m/s2 braking year-round and, with reform of driving practices, the loss would be largely eliminated.”

Iain said that a bid to Network Rail’s Performance Innovation Fund (PIF) for retrofitting DVRS to the 43-unit Class 323 fleet had been successful. He had used a similar

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74,000 journeys were analysed, a total of over 0.5 billion records. There were delays in each of the four phases, with autumn running slower than summer by these average amounts - dwell time, circa 2.5 seconds; acceleration, about 1 second; cruising speed, about 1 second; braking, 4 seconds. It is worth noting that the Class 323 has 66% axles motored and other classes - with a lower percentage of axles motored - might suffer more problems with acceleration in the autumn.

Summarising the data in three figures, Peter said that dwell time and run time were on average 2.5 seconds and 6 seconds respectively slower in the autumn than in summer, which totalled circa 87 seconds delay over a whole journey. Small autumn delays accumulated along the line to become significant delays which were, on average, not recovered.

Peter concluded that DVRS would provide confidence in braking and, with suitable changes to driving policy, performance in the autumn could be little different to that in the summer.

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evaluation process for the rest of the GB passenger fleet delivering a CAPEX estimate of approximately £330 million, circa £2 million OPEX costs and some £66 million of benefits per year, indicating a payback period of 8-9 years.

He warned that there is an issue with the rollout of ETCS and the way it has quite crude allowances for low adhesion. This may be a significant problem. There is a parameter called Kwet which is a measure of a train’s low adhesion performance; the rules dictate that this value is established with the sanders disabled. The emergency braking curve for nearly all passenger trains may therefore be pessimistic at all times, with or without DVRS. This will affect headway performance more than run times. Perhaps it is time for sanders to be an essential part of the safety-critical braking system.

Ending on a positive note, Iain said that DVRS is the single biggest performance initiative available to GB Rail using simple and proved technology, giving 0.6m/s2 braking on poor adhesion days. This, together with targeted, vegetation management and more attention to detail of water jetting, could provide a near complete autumn solution.

Sample inter-station run with many journeys superimposed to show summer journeys quicker than in the autumn.

MALCOLM DOBELL

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PHOTO: ELLIOTT BROWN

Simulation work

Two Class 323 trains on the Cross City Line at Cotteridge Park.

A four-car unit showing the arrangement of the modelled adhesion systems.

CORE VISUAL: CHILTERN006

EPF

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Braking developments Paul Allen, Institute of Rail Research at the University of Huddersfield (IRR), and Phil Martin, Transport Research Laboratory (TRL), talked about ‘Predictable and Optimised Braking: An Intelligent Blended Braking (iBB) Approach’ funded by RSSB and led by Alstom, with support from Knorr Bremse, Northern Trains and Wabtec-Faveley. iBB is essentially the intelligent blending of conventional and adhesion-independent/ adhesion-raising brake system technologies, the simulated systems consisting of ElectroPneumatic Friction brake (EPF), Electro-Dynamic Regenerative brake (EDR), Eddy Current Brake (ECB), Magnetic Track Brake (MTB), intelligent sanders and adaptive Wheel-Slide Protection (aWSP) which adapts its control algorithm to the level of adhesion.

‘Intelligent braking’ means that the applied brake rate can be varied along the train to make the best of or even improve the adhesion levels whilst delivering the brake rate demanded by the driver, controlled by a dynamic Train Brake Controller (dTBC) - in essence, the high-level controller of aWSP. This compares with the conventional systems where the same brake rate is applied along the train unless the WSP intervenes to reduce the brake application on one or more wheelsets.

IRR’s LABRADOR modelling tool was used to assess the impact of these brake systems individually and in combination. The aim was to deliver 0.6m/s2 braking under very low adhesion conditions (adhesion coefficient of 0.02).

The researchers were keen to assess the benefits of braking solutions that are independent or semi-independent of adhesion.

ECBs work something like a linear induction motor in dynamic braking mode and need no adhesion to operate, but they are ineffective at low speeds. Another technology is MTBs where bogie-mounted electro-magnets grip the rail head. Although MTBs still rely on friction, they tend to scrape off any contaminants on the railhead, making them very effective brakes.

iBB Control

Rail Engineer | Issue 190 | May-Jun 2021

dTCB

The train model was based on the dynamics of the Class 458 EMU and the characteristics of the various braking systems were provided by the suppliers, sometimes based on the expected performance of products not yet on the market. Theoretical four-car and twocar configurations were tested using three adhesion conditions for various levels of performance: Step 2 and 3 brake rates, variable starting speeds, degraded mode operating and for the individual performance of the various sub-systems.

Work was carried out on Wabtec Faiveley’s four-axle rolling rig in Italy to study the adhesion interactions between axles specifically to establish how various aWSP algorithms enabled increase in adhesion from one axle to the next.

The simulation work demonstrated that the target of delivering a 0.6m/s2 brake rate in very low adhesion conditions is indeed possible and can be achieved for a four-car unit without the need for adhesion-independent braking systems. Paul asserted that this is potentially of great significance to the industry as the solution relies solely on an upgrade to the sanders, WSP and brake system control strategy, and therefore offers a practical solution as an immediate response to the adhesion problem.

Paul said that delivering a similar outcome for a two-car unit was much more challenging.

With only eight axles, Paul said it was unlikely that the 0.6m/s2 brake rate target in very low adhesion conditions could be achieved without adding additional systems such as the ECB. Based on TRL’s work using their TRIO rail operations performance modelling tool, the best business case for retrofit was for a WSP and intelligent sanding, but a strong business case could be generated for adhesion-independent brakes (ECB or MTB) if they were considered at the new build stage. Paul also outlined plans for further research including service trials with TOC support, refinements to the business case, understanding the impact of MTBs on existing infrastructure and understanding how well MTBs condition the railhead.

Thanks to RSSB and the speakers for their help in the preparation of this article.

The second part of our review of ADHERE’s 2021 webinar series will appear in the July/ August issue of Rail Engineer.

MTB on bogie

indECB on bogie

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Grounded in our unrivalled industry knowledge and expertise, we can save time, protect budget and improve quality on your next project – helping you get the job done safer and better than ever before.

Call 01962 711642 for more or go online. totalrailsolutions.co.uk

FEATURE

DAVID SHIRRES

an

INNOVATIVE

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fter more than a year away from real events, speaking to rows of faces on our computer screens has become all too familiar. Yet this is only possible with the relatively recent proliferation of high-bandwidth internet connectivity, smart phones, cloud computing and videoconferencing apps. Not surprisingly, their use has been accelerated by the pandemic, with Zoom reporting a 535% increase in its daily traffic in 2020.

PHOTO: NIKADA

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Although this is a good way of learning and keeping in touch, it is a poor substitute for face-to-face gatherings. Pre-Covid, the networking opportunities that conferences provided made them popular events.

Providing an equivalent experience online has proved difficult.

Rail Engineer | Issue 190 | May-Jun 2021

This was the challenge faced by the Railway Industry Association (RIA) when making their popular innovation conference a virtual event.

Rail Engineer has reported on the previous seven conferences and was interested to gauge how this one compared. It took place from 28-30 April.

FEATURE Key speakers Introducing the conference were RIA’s Chief Executive, Darren Caplan, and Technical Director, David Clarke. Caplan set out RIA’s vision of an innovative, digitised and green rail industry, and had no doubt that passenger numbers would bounce back post-Coronavirus as videoconferencing actually generated travel. He was pleased to see how rail had supported the economy during the worst of the crisis when it accounted for 25% of UK construction.

Clarke explained that the conference’s theme, ‘The Railway of the Future’, was about making sure that the railway is ready for whatever the future holds. He also launched RIA’s new collaboration with ITN Productions, ‘MADE With Rail’, which highlights the latest developments in Materials, Automation, Data and Energy (MADE) and RIA’s new Unlocking Innovation website (www.riagb.org.uk/UnlockingInnovation).

Rail Minister, Chris Heaton-Harris, responded to Caplan’s enquiries about the delays to both the Williams Review and the response to Network Rail’s Traction Decarbonisation Network Strategy (TDNS). He advised that there will be a white paper with measures prompted

by Williams “very very shortly” and that there would soon be a response to TDNS which would “make people on this call very happy”.

He considered the modern railway to be a catalyst for growth and prosperity on which the government had committed significant investment, but noted that railways had to be more affordable. Hence it is essential that Project SPEED (Issue 189 Mar-Apr 2021) reduces project costs and timescales.

Heaton-Harris is keen for UK rail to become a leader in rail technology and was pleased to see world-class testing sites being developed. He wanted rail to work with government to exploit the opportunities to innovate.

In an interview with RIA’s David Clarke, Network Rail’s CEO, Andrew Haines, was asked what he would like to see the future look like.

His response was the three Ss of Safety (constant improvement), Simplicity (for passengers and freight customers) and Sustainability. He emphasised the latter was not just about the environment, but required a cost-effective railway which must be adaptable and not slow to innovate. He also emphasised the importance of Project SPEED and noted that the most difficult part of his job is convincing the Treasury to invest as their perception is that the railway has a poor delivery record.

Haines felt that the Williams Review would address the fragmentation and contractualisation which produces perverse incentives and makes it difficult to innovate.

He was confident of the railway’s post-Covid recovery, but cautioned that it will no longer be bankrolled by commuters. Hence a welcoming, reliable railway with affordable solutions is

RIA’s conference was hosted by LJ Rich.

David Clarke interviewing Andrew Haines.

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FEATURE needed. In addition, access strategies need to balance work savings against revenue streams for the best whole-industry decision.

He thought the argument that rail needs an injection of funding to decarbonise was being won. Haines noted how Scottish electrification is providing a continuous workstream which creates supply chain stability, continuous improvement and lower costs, as shown elsewhere in this issue. Furthermore, new electrification technologies such as surge arresters were now reducing the cost of electrification. He was pleased that the electrification contract for the trans-Pennine route upgrade had been let below the budget price.

Rail technology keynotes The conference technical keynote presentations provided perspectives from a train operator, rolling stock company and an infrastructure manager.

Rail Engineer | Issue 190 | May-Jun 2021

West Coast Partnership is the ‘shadow operator’ developing the initial HS2 services.

Its Managing Director, Caroline Donaldson, explained how innovation was being encouraged to provide an exceptional passenger experience.

She felt that innovation had to be embedded in HS2 operations to get ahead of ever-changing customer demands. For example, innovation was needed to improve seat reservations and make it easier to get to stations, as well as for fleet maintenance and cleaning. She asked businesses to contact her if they have something to contribute.

Martin Ertl, Vice President, Innovation and Portfolio Management at Knorr-Bremse, also felt that rail must use its technical know-how to develop passenger-focused solutions to drive recovery and growth. This includes technologies to increase infrastructure capacity such as Knorr Bremse’s Reproductive Braking Distance technology which always ensures minimum braking distance is maintained. He also considered

FEATURE that ‘intelligence-driven maintenance’ is needed if there is to be zero disruption to services.

Ertl was concerned about restrictions on the use of data and made a plea for open data. For him, the issue is not data ownership as data only has value when it is used to generate useful information. Experience shows that this is most likely when data is shared.

Network Rail’s Chief Technology Officer, Robert Ampomah, felt that archaic things were still being done such as manual train coupling, inspections and maintenance. Such things needed to be mechanised and automated, he asserted. In CP6, the company has £245 million to invest in its R&D portfolio, of which £85 million has already been invested. Network Rail is also working with UKRRIN and other partners to leverage additional funding opportunities.

He advised that Network Rail’s R&D investment to date had delivered benefits of around £300 million, with a rate of return of about five years. Such projects included plain line pattern

recognition and digitised lineside inspection of vegetation. Ongoing work includes operational data sandbox, fibre sensing, automated repair, cost-efficient electrification and earthworks stabilisation. Ampomah concluded his presentation with his own mnemonic of three Cs: Collaboration, Creativity and Cost-reduction.

Although innovation brings technological changes, Irina Parsina from Microsoft Teams reminded the conference that innovation was all about people. Organisations have to create the climate for successful innovation and not forget that any innovation is designed for the human.

She felt it was important to understand that change does not always come easily due to human traits of laziness, risk aversion and resistance to change. In the rail industry, Parsina was clear that barriers had to be broken down to enable innovation and ensure that everyone has a voice.

Virtual round tables The first panel discussion considered three themes of the new Rail Technical Strategy (RTS): Easy to Use for All, Optimised Train Operations and Reliable/Easy to Maintain. Sharon Odetunde of RSSB explained how innovations from the ‘Easy to Use’ theme will make rail more attractive to passengers. Clive Roberts of the University of Birmingham spoke about ‘Optimised Train Operations’, the benefits of more flexible train timetables and the challenges of ETCS on a mixed-traffic railway.

David Rowe of Network Rail considered how the ‘Reliable/Easy to Maintain’ theme was focusing on asset reliability whilst David White of HS2 explained how the company was taking a whole systems approach to treat data as an asset which included the use of digital twins.

This topic was continued in the ‘Data-Driven Growth’ session in which Ian McLaren of Govia Thameslink Railways (GTR) explained why GTR was making its data and apps freely available.

Such apps include train cleaning, desk booking and Covid testing. James Bain of Worldline underscored this point by mentioning the Rail Data Council which aims to better coordinate open access to UK rail data.

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Rolling wheel test rig at the University of Huddersfield.

IRSE President, Ian Bridges, spoke of the benefits of using data for predictive maintenance and of digital twins. Will Wilson of Siemens noted that real-time data was becoming increasingly essential, yet the vast amount collected is more than can be processed. He felt the challenge was to clearly present relevant information, for example providing passengers with train loading during the pandemic.

The ‘Innovation for Economic Growth’ session considered opportunities and obstacles for innovation. IAND’s founder and CEO, and chair of the Royal Academy for Engineering’s Enterprise Hub’s Innovators Network, Elspeth Finch, explained the UK Government initiatives to encourage innovation and considered the difficult problem of scaling-up new technologies.

She suggested that SMEs could work with large companies to innovate at scale.

Paul Sheerin, Scottish Engineering’s CEO, described how a rail ‘cluster builder’ is being established for businesses wishing to increase their involvement with the Scottish rail sector and felt that Scotland’s rail electrification was a catalyst attracting new companies. James Davies of Industry Wales emphasised the importance of

A proposed VLR vehicle for Coventry.

Rail Engineer | Issue 190 | May-Jun 2021

supply chains working across different sectors.

Lucy Prior MBE of 3Squared emphasised the diversity of SMEs. She urged companies to “network and let people know” about their products and to “keep listening” in order to “keep innovating”.

The discussion following this session highlighted the rail industry’s lack of diversity and how procurement was a barrier to innovation, but could be an enabler with a change of thinking.

The decarbonisation session was introduced by presentations on hydrogen trains, battery technologies and electrification. Garry Keenor of Atkins noted that whilst batteries and hydrogen clearly have a role in rail decarbonisation, for most of the network electrification is the only option. This was the conclusion of the ‘Why Rail Electrification?’ report that he coauthored. Keenor stressed the need for a rolling electrification programme and noted that, without this, the railway will not decarbonise and will be more expensive to run. Panel members concurred with this view.

RSSB’s CEO, Mark Phillips, absolutely supported the requirement for a major electrification programme, but noted the difficulties of convincing government that this can be done efficiently. Rail Delivery Group’s CEO, Jaqueline Starr, considered that rail must also drive modal shift for which a customer-focused railway was essential.

Porterbrook’s CEO, Mary Grant, described how her company was hybridising existing trains to reduce their emissions and hoped her company’s hydrogen train would be in passenger service by 2022. Network Rail’s Safety and Engineering Director, Martin Frobisher, noted that November’s COP26 UN climate change conference in Glasgow was a global opportunity to showcase the rail sector’s decarbonisation initiatives. He also considered that indirect emissions were a big challenge and wanted to see the supply chain commit to following Network Rail’s example by adopting science-based environmental targets.

FEATURE Innovation capabilities

Other virtual aspects

Current and future facilities for rail innovation were considered in sessions about current facilities offered by the UK Rail Research and Innovation Network (UKRRIN) and future centres under construction.

Speakers at the first session were Amanda Mackie, Professor Simon Iwnicki, Professor Clive Roberts and Professor William Powrie who respectively lead UKRRIN’s centres of excellence for testing, rolling stock, digital systems and infrastructure. Mackie described how Network Rail’s test facilities are used to develop rail innovations at higher technology readiness levels.

Professor Iwnicki described the University of Huddersfield’s rolling wheel test rig and new pantograph test rig. He explained how digital modelling would enable the latter to simulate the operation of multiple pantographs on a train. Professor Roberts advised that a new purpose-built centre for digital railway engineering at the University of Birmingham had opened in November. An example of this centre’s work will be the development of an HS2 digital twin to provide system testing in laboratory settings.

In the next session, Unipart Rail’s Engineering Director, Professor Steve Ingleton, described how UKRRIN’s Innovation and Technology hub at Doncaster - due to open in the summer - will provide a permanent rail innovation exhibition to showcase UKRRIN’s achievements. This is intended to both encourage innovation and attract people to the industry.

Arthur Emyr from the Welsh Government described the £150 million rail testing facility to be built on the site of a closed opencast mine near Ystradgynlais in Powys with 6.9km of 170kph electrified track and 4.5km of low-speed high-tonnage track. The Welsh Government is working with industry and the Welsh supply chain to establish this centre which is expected to be completed by 2025.

Richard Jones of the Black Country Innovative Manufacturing Organisation explained how the £29 million Very Light Rail (VLR) national innovation centre at Dudley is intended to promote lower-cost VLR solutions across the UK. At £10 million/km, VLR’s cost is expected to be a quarter of a conventional tram system. Jones felt that this could enable the UK to create a whole new VLR industry as cities around the world are desperate for such affordable mobility solutions. The centre will have a 2.2km conventional rail test track and is to test a novel lightweight VLR track. It is expected to open early next year and will have a dynamometer system, simulation suites and electronic and software laboratories.

As well as presentations and round tables, the conference had other virtual experiences. These were an exhibition hall, parallel workshops, table sessions and evening events. Whilst these were quite different from previous conferences, they still offered plenty of opportunities for learning and meeting new people.

The virtual stands in the exhibition included those of conference strategic partners Network Rail and UKRRIN, and sponsors Hitachi, KnorrBremse, Capgemini Engineering, Railtex, Withers and Rogers, Altran, Porterbrook, Harmonic and Ricardo Rail.

Workshops were run by UKRRIN, Network Rail, Transport for London and non-technical RTS themes to accelerate successful innovation. Those I attended included RTS ‘Rapid Benefit Realisation’ and ‘Digitally Talented Workforce’ themes, and a Network Rail workshop on cost-effective electrification.

At the table sessions, delegates were able to discuss a specific innovation topic, meet a particular company or generally network. These were cabaret-style virtual tables of six, hosted by various companies and organisations which also provided a rare opportunity for a catch-up.

A particularly interesting table was hosted by James Featherstone and Patsy Brady of Network Rail’s Digital Innovation and Collaboration in Engineering (DICE) initiative. This has teams of graduates competing to develop digital solutions to Network Rail’s challenge statements. DICE started in 2018 and this year has 19 teams of five developing solutions for sustainability issues.

Four of these will go forward to the final which is judged by Andrew Haines and other Network Rail executives. Winners then receive funding to develop their products.

On the conference’s first evening, there was a virtual dinner with tables of six which included an organised tasting of beer sent to them beforehand! The next evening featured an interview with Charles Duke who was the tenth astronaut to walk on the moon. At the age of 85, he is still the youngest person to have done so. Duke noted that his smartphone has 800,000 times the memory of the computer that controlled his moon landing.

This year, RIA’s virtual innovation conference was certainly not the same as previous events, yet the information and insights it provided were not diminished. It was also a thoroughly enjoyable experience. The RIA team, and host LJ Rich, deserve much credit for their innovative approach.

Surge arresters can eliminate the need for bridge reconstructions.

Rail Engineer | Issue 190 | May-Jun 2021

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FEATURE

Gauge clearance software: AN UNAVOIDABLE PAIN?

Why is gauging important?

C

olin Johnson, Managing Director of D/Gauge has a straightforward view on gauging software: it should be inherently fast, intelligent and fuss-

free. The Derby-based company launched its much-anticipated D/Gauge Rift product in an online launch to over 300 attendees, marking a new era in intelligent clearance assessment.

So, what is D/Gauge Rift and why is it important?

The largest software update in the market for 20 years, gauging engineers and software specialists combined their skills to create a revolutionary new system in an area that was in need of modernisation.

Rail Engineer | Issue 190 | May-Jun 2021

Gauging can be likened to accountancy, which also used to have complex associated software, inaccessible to the occasional or nonspecialist user. Then QuickBooks was introduced, changing the way individuals perceived finance management. The power of simple, clean software unlocked wider potential and introduced more people to managing books.

Finance and gauging are both critical subjects - tasks that inevitably need to be done. Mistakes could be far-reaching and the longer you leave it, the more painful it could be to do.

The challenge was to transform gauging from a painful chore to an integral part of the design process for track and infrastructure designers. D/ Gauge Rift is set to release the gauging software environment from its historic shackles and start the next era of clearance assessment.

Colin comments: “We know gauging is a necessary evil for some and it’s one of those really important things that is implemented for a whole multitude of reasons, such as network capacity, route opportunity and passenger safety. What we want to do is make it a lot more enjoyable! We’re confident with D/Gauge Rift that gauging can become less mundane and an intuitive part of the process.”

FEATURE

From wet string to LiDAR David Johnson, Technical Director of D/Gauge, was the first person to digitalise gauging, advancing from poles and wet string to laser scanning and computerised software.

His first programmes led to the birth of VDP Gauging, ITD Gauging and Clear Route, to name a few.

With a strong pedigree of clearance assessment and an exceptional team of engineers behind him, the D/Gauge team expanded to engage their software design capabilities. The aim was simple - to create an easy-to-use but powerful piece of software to write clearance assessment for the future.

Technology is changing rapidly and the speed of innovation in the railway industry is at an all-time high.

From SMEs like D/Gauge to large corporations, the railway is utilising modern technology to supercharge our network.

Recent technologies have multiplied the accuracy of data that is available, creating different challenges for engineers.

Increased plot points lead to more accurate models, less conservative gauging and the ability to unlock more routes, but they come at the price of being able to successfully interpret, interrogate and use the information.

With over 200 vehicle class types already in circulation (and this number is still rising), the vehicle complexity is sure to increase. Pair this with the evergrowing LiDAR and scanning technology apparatus - capable of recording tens of thousands of plot points on a structure and we all know the existing software just cannot handle that level of detail.

Scaling up is key, especially as the industry predicts that freight gauging will become more wagon and load-specific, leading to a much bigger

matrix of information available to use. Creating a package that is fully capable to handle, analyse and present this data was the driving force for D/ Gauge team.

Starting from the ground up, D/Gauge has built an entirely new software platform that can manage the increasing demands of our network.

Reacting to industry requirements The inspiration for D/Gauge Rift comes from the market’s gripes and requirement for

Managing Director Colin Johnson launching D/Gauge Rift.

Rail Engineer | Issue 190 | May-Jun 2021

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FEATURE a tool that is capable of handling today’s situations with today’s user experience. “We’ve been batting off requests to make faster gauging software for the past decade”, says Colin Johnson. “Speed, however, is just one element of the process and should have much less gravitas attached to it. We are used to quick software to empower efficiency in everything else, so here is the gauging tool we all need.

As the volume and complexity of datasets continues to grow, I know we must approach gauging assessment in a unique way, especially to future proof it.”

Time is already limited. Any hiccups in the set up or glitch in the run can delay projects, add unnecessary costs and fray timelines. Managing Director of Bonner Rail, Mark Bonner, was a key development partner in the creation of D/ Gauge Rift. His team of excellent engineers worked collaboratively with D/Gauge to create a product that is raising the bar. Mark said: “It’s not like you are saving 10% of the time; you’re completing it in 10% of the time.” By fully utilising the power of cloud-based computing, speed becomes secondary to the real problem at hand: ensuring the vehicle fits!

Colin Johnson continues: “We’ve created something that is robust and reliable. It is something that superpowers our current need for gauging and can scale up for the future of clearance assessment requirements.

“Gauging software should let track designers run enough permutations to optimise design work. It should be fast enough that processing time shouldn’t even be part of your thinking.”

For engineers, by engineers The engineering and software teams.

The D/Gauge Rift platform has been extensively tested, refined and tweaked to meet the user’s needs. Working closely with development

Rail Engineer | Issue 190 | May-Jun 2021

partners - including Bonner Rail and others - D/Gauge Head of Software has made usability and experience at the top of his list.

“We love a challenge”, says Dave Steward, Head of Software, “and we take the actual problem that the individual is presenting, fully understand it, go away and come up with a brand new, inspired way of displaying or inputting that information. We went back to basics in our design process to analyse the core information that drives decisions and offer better support.”

Existing software is notorious for its manual, repetitive processes. Downloading, importing, setup, post processing of data: all manual processes that add time, effort, risk of error and additional training to be able to use them. D/ Gauge Rift is built to be a centralised system with principles of sharing weaved-in throughout.

The result: the engineer has more time to focus on the assessment results and track design, where they add real value.

About D/Gauge Founded in 2008, D/Gauge was involved in cutting-edge research - creating smarter, deeper datasets - and has invested in a new software approach which is fit for the future.

Leaders in gauging, they have over 40 years’ experience.

D/Gauge may be new to open-market clearance assessment software, but it has been recognised in the industry for its consultancy services. Led by Ian Johnston, Head of Engineering, the team of engineers has a reputation for solving complex gauging calculations, supporting electrification schemes, vehicle introduction and much more. www.dgauge.co.uk

A Better, Safer Railway

Discover how industry, with support from RSSB, is keeping Britain’s Railways safe.

Download RSSB’s Annual Health and Safety report. This report reviews the year’s health and safety performance, looks at the lessons that can be learned, identifies emerging risks, and outlines what the industry is doing to improve health and safety.

3 16

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One passenger, two members of train crew

public fatalities at other locations

Eleven trespassers, five on level crossings

3

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Not in train accidents

78

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1

passenger fatality in a station

253

suicides or suspected suicides

Download the full report at: www.rssb.co.uk/AHSR

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FEATURE

Level Crossings DELEGATION OF RESPONSIBILITY COLIN WHEELER

I

have memories of seeing and, on occasions, examining level crossings in a number of European countries. Unsurprisingly, the safety record across the continent varies widely but, between 2014-2018, an average of 1.33 incidents occurred for every 1,000 track kilometres. Ireland and the UK perform best at 0.2, while Estonia and Slovakia are at the other end of the scale at 4.9.

Statistics never tell the full story, but nowhere appears to be quite as hazardous as India where trains operate on around 64,000km of railway with 40,500 crossings, equating to one every 1.5km. Indian Railways are looking to increase the number of crossings with manned barriers from the current 16,000. Crossings adjacent to canals have warning signs, but reports indicate that over 2,800 are open crossings, devoid of barriers and signage.

Fatalities rose from 1,408 in 2018 to 1,788 the following year.

In Britain and Europe

PHOTO: AI PHOTOGRAPIC

Even in European countries, signage and barriers often look less substantial than those used in Britain. In decades past, groups of British Rail office staff worked exclusively on level crossings, ensuring they met the standards decreed by the then Railway Inspectorate and Department of Transport. Not only were the barriers and gates subject to a prescribed standard, so too were the road markings, signage and road approach visibility.

Generally, the number of fatalities at UK level crossings has followed a downwards trend over the past 20 years. Back in 2003/4, 11 pedestrians and five vehicle occupants lost their lives; in 2019/20, two pedestrians were killed but no vehicle occupants.

There were however 316 near misses with pedestrians, the highest number since 2011-12.

For context, we have around 5,800 level crossings on main lines in Britain, with user-worked and foot crossings each amounting to around 2,000. We have over 800 automatic crossings and a similar number under manual control. In addition, 1,500 level crossings are found on our heritage and minor railways.

The industry’s continued focus on this major risk area has seen the creation of enhanced, modelling tools using the latest intelligence. Safeguards such as obstacle detection technology have been deployed and red-light enforcement cameras installed. A cost-effective train-detection warning solution is being developed for footpath and bridleway crossings. These all add to previous performance improvements brought, for example, by the introduction of precast road surface units that fitted between and alongside running rails, and could be removed relatively easily to allow the track to be maintained or replaced.

Safety principles In 2011, the Office of Rail and Road (ORR) published its ‘Level crossings: A guide for managers, designers and operators Railway Safety Publication 7’ - usually referred to as RSP7 - which is currently in use. However, on 20th January this year, the ORR opened consultation on its replacement by a draft document entitled ‘Principles of Level Crossing Safety’, described as a guidance publication.

Rail Engineer | Issue 190 | May-Jun 2021

The ORR says that RSP7 can be difficult to use because it is long, prescriptive and contains information that is out-of-date or superseded. In particular, it duplicates information that is available elsewhere, such as in technical standards.

The new draft document is divided into four sections. The first describes the role of the ORR, while Section 2 deals with risk assessment. The following sections detail a total of 23 safety principles and are: Section 3 ‘Safe for the user’, Section 4 ‘Safe railway’ and Section 5 ‘Safe highway’.

The ORR has said that its aim is “to support the assessment and control of risks at level crossings” and to provide a resource that supports “the design, management and operation of level crossings”. My initial assumption was that the ORR’s intention was to step back and let crossing owners take greater responsibility.

ORR webinar Rail Engineer joined 40 individuals who were invited to attend an ORR webinar on 23rd February. The speakers from the ORR were Tracy Phillips - Head of Safety Policy and Corporate Support, Paul Appleton - Deputy Director, Railway

PHOTO: NORTH LIGHT IMAGES

FEATURE

Safety, Clare Povey - Principal Inspector of Level Crossing Strategy, and Dawn Russell - Senior Policy Manager, Railway Health and Safety.

Paul, with 20 years’ experience as an inspector, said that the intention was to replace the current prescriptive and rigorous rules with improved risk assessments. Local authorities and others have been involved in steering groups and new technologies are providing options for pedestrian crossings.

Clare Povey reminded us of the ORR’s role, with their 300 professional staff operating from six offices, including one

Certificate: PA05/04429

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in Scotland. She described the ORR as an “independent, non-ministerial UK Government Department”. Of RSP7, she said it was in need of revisiting and replacing by a system with a wider scope. Although it will be withdrawn, she suggested RSP7 should continue to be used by others and be adopted as an industry standard.

Dawn Russell said that the withdrawal of RSP7 was part of a wider review of ORR-published information and reminded us that the safety of users, the railway and the highway are paramount, as well as discouraging trespass. She spoke of

Rosehill Rail’s rubber level crossing systems are designed to provide dimensional stability at any angle and in all operating conditions. They are easy to install and maintain, cost-effective and reliable, enabling the safe transit of vehicles and pedestrians. Think Rosehill.

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Rail Engineer | Issue 190 | May-Jun 2021 21/05/2021 10:28

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FEATURE householders. These drivers knew about the hazards of occupational level crossings on their patch, how they were operated and what to look out for. That knowledge has largely gone.

The closure option

(Above) Network Rail is proposing to close two crossings in Burscough, West Lancashire. the need for collaboration to improve understanding of users and how they behave, and the ORR’s intended move away from categorising crossings.

Reassuringly, we were told that the ORR is developing “two or three more case study-based guides” which will be made available on its website in future.

Question time Questions were limited to those submitted in message form as the presentations were made and, for the most part, were of a practical, site-specific nature posed by council highways staff. Barrier down time, signalling delays, planning legislative requirements and the challenges posed by bridleways and private roadways all were mentioned.

The speakers reminded us that the longterm aim is to eliminate all level crossings, although they acknowledged that this is not a realistic objective.

With the replacement of RSP7, the Rail Safety and Standards Board (RSSB) will provide further information for the ORR website. Interestingly there were no references to light rail or tram crossings.

The delivery conundrum Reflecting after the session, I concluded that the ORR will be stepping back from leading, even through the recommendation of factors to be taken into account when specifying safety systems, and installing or upgrading level crossings. How will this affect crossing safety? Perhaps only time will tell.

One area that the railway cannot easily influence is changes in road traffic which can increase existing hazards or introduce new ones. Vehicles have generally grown in size over the years to provide more capacity and push up productivity; the pressure on delivery drivers has increased, with the number of drop-offs and collections influencing their pay. And they often come from further afield, with little local knowledge.

Although satnavs are much more reliable these days, they can direct vehicles down lanes for which they are not suitable, sometimes with tragic consequences.

In years gone by, post vans were regularly driven by locals who would also collect mail in country areas and might well offer to deliver other small items to

Rail Engineer | Issue 190 | May-Jun 2021

We still have many under-used level crossings and Network Rail is rightly pursuing a programme to “reduce the risks that level crossings pose to the public, passengers and rail industry workforce”.

A good example is the proposal to close two crossings in Burscough, West Lancashire, to motor vehicles and realign the routes for pedestrians, cyclists and horse riders to shorten the time they spend on the tracks. Affected are Shaws level crossing on Sutch Lane and Crabtree crossing on Crabtree Lane.

Network Rail has said that “this will improve safety for everyone and reduce the risk that level crossings present to passengers and crossing users”. They also state that, when implemented, “the maintenance and operation of services between Wigan and Southport will be easier and costs will be reduced”. Local MP Rosie Cooper recognises that the changes may prove inconvenient for some, but “safety has to come first”.

In many parts of Britain, industrial development and new housing have taken place, swallowing previously quiet and remote level crossings so that road traffic far exceeds the original design remits in terms of types, weights and frequencies.

In some places, replacing a crossing by an overbridge or underpass may be a reasonable option, but elsewhere is often difficult to justify.

The way forward The draft ORR document recognises the importance of all parties working together to assess level crossing risks so that opportunities can be taken to eliminate hazards where possible.

Early engagement and consideration of solutions from different perspectives provides better opportunities for innovation in risk management. Crucially it makes clear that good level crossing design understands the needs and limitations of the user, taking into account normal use, reasonably foreseeable human error and deliberate misuse.

The consultation period on the new principles ended on 26th February.

Publication will follow consideration of the responses which will all be published on the ORR website.

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FEATURE

PEAK

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PERFORMANCE F or most of us, bank holidays are a time to gather in the pursuit of enjoyment. But all that has been curtailed this year and last by…you know what. When we’ve most needed things to smile at, they’ve been hard to come by.

An underpass constructed beneath the MaryleboneAynho Junction line at Bicester.

It was business as usual though - more or less - for the railway family over Easter as the supply chain progressed £116M worth of engineering work at 4,000 worksites in 1,200 possessions, completing major enhancements, core renewals and routine maintenance. And over the May bank holiday weekend, there was activity at a further 3,000 sites, with a value of around £80M. At 50 of these

Rail Engineer | Issue 190 | May-Jun 2021

locations, the projects were identified as ‘red’ through the Delivering Work Within Possessions standard, bringing a greater risk of overrun and significant impacts on services.

The ongoing East Coast Upgrade was pushed forward at King’s Cross with the replacement of track, signalling and overhead line equipment through the one-and-a-half mile section approaching the station.

The signal box was taken out

of service on 23 April during a four-day closure of the station; control has now been transferred to York ROC. Gasworks East Tunnel reopened after 40+ years of redundancy on 26 April.

Enabling works for HS2 were undertaken at Euston whilst large-scale enhancements continued in Leeds. But, away from these bright spotlights, a collection of smaller schemes came to fruition over the two bank holidays, bringing benefits both operationally and for the railway’s customers. Here are the edited highlights.

New bridges The A4095 strategic link road is an important element of the North West Bicester eco-town master plan. To build it, a new underbridge was needed to support the Marylebone-Aynho Junction line, together with a nearby underpass. Both structures were constructed over Easter, together with 400m of track renewals.

During the 100-hour possession, 21,000 tonnes of embankment were removed, allowing the prefabricated structures - with a combined weight of 2,100 tonnes - to be moved into position on transporters.

FEATURE In Dartford, three metal bridge decks over Hythe Street were replaced with ‘U’ decks and holding-down restraints to mitigate against bridge strikes.

Repairs to the brickwork and abutment drainage were also undertaken. The structures were life-expired and contained hidden critical elements which could not easily be inspected.

A crane and transporter were used to replace a bridge at Warrington Bank Quay Station, lifting out the old deck sections and installing two concrete-encased steel units.

Another bridge, which had previously been infilled with foam concrete, was also taken out. The removal of longitudinal timbers from the workbank will reduce future maintenance requirements.

Over the May Bank Holiday, the EWR (East West Rail) Alliance completed the installation of 103 deck beams over the West Coast Main Line and re-registered overhead line equipment on all four main lines through Bletchley. This work continued the Alliance’s programme to complete a flyover, allowing construction of the new railway towards Bicester to get underway this winter.

Track replacement Significant plain line and S&C projects were undertaken, including at the site of the Brent Cross West Station which will bring 7,500 new homes within 15 minutes of central London.

As well as slewing the Slow lines and renewing three sets of points, signals were relocated and the OLE realigned.

At Stratford, 687 yards of plain line was renewed on the Up Main through Platform 9

using seven engineering trains.

The new track was welded and stressed, enabling the site to be handed back at 60mph rather than the booked 50mph TSR. Track quality data had deemed a site at Newark Castle Station in Nottinghamshire to be very

poor, with numerous track defects recorded historically.

Here, the renewal of 40 yards of track through a level crossing has removed the risk of a speed restriction being imposed.

The upgrading of Wilton Junction between Salisbury and Wilton included the renewal of all the S&C and associated plain line. The primary driver was to renew the life-expired ballast and track components, improving performance and geometry.

Meanwhile at Nunnery Junction, Sheffield, a twostage project was completed involving the relaying of the Up/Down Main and Worksop

Helping to make a difference

lines, four point renewals, two points being plain-lined and reballasting across the entire junction. The use of a welding supervisor allowed all 80 welds to be completed, with the railway opening on time at 70mph.

Operational improvements The Stratford rewire project is replacing the existing overhead line equipment with a modern auto-tensioned design between Stratford and Maryland stations. Currently, the OLE is fixed termination

Work gets underway on the replacement of Hythe Street bridge in Dartford.

Overhead line work near Stratford in east London.

Health, welfare and financial benefits for those working in the public transport industry ...people like you!

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Transport Benevolent Fund CIO, known as TBF, is registered charity in England and Wales, 1160901, and Scotland, SC047016.

Rail Engineer | Issue 190 | May-Jun 2021

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FEATURE highest-risk Automatic Half Barrier (AHB) level crossing at Cornton with manuallycontrolled barriers monitored by obstacle detection. The AHB crossing was decommissioned from the signalling interlocking and work got underway on the installation of equipment for the new system.

Overall performance

A bridge replacement makes progress at Warrington Bank Quay.

Track work at the site of the new Brent Cross West Station.

and cannot maintain full tension during periods of hot weather, requiring speed restrictions to prevent dewirements.

Considerable progress was made over Easter.

Meanwhile, works were undertaken to increase the resilience of overhead line equipment within Beechwood Tunnel, west of Coventry, following severe disruption caused by a failure during summer 2019. Included was the replacement of the contact wire and installation of an equalising plate.

The Feltham & Wokingham Resignalling Programme involves the renewal of all signalling assets and recontrolling the system to the Basingstoke Rail Operating Centre (BROC). Phase 1 covers

Rail Engineer | Issue 190 | May-Jun 2021

the area from Richmond to Whitton and Norbiton to Twickenham, extending the ElectroLogIXS signalling system and delivering enhancements with the installation of two new crossovers at Twickenham and St Margarets.

Over the five-day Easter commissioning period, the project completed a number of key tasks including the renewal of the road lights and barriers at Strawberry Hill level crossing, whilst 45 life-expired signals were removed, six new signals erected, telecoms alterations completed for signal post telephones, system testing and recontrol of the Shepperton branch to BROC. In May, engineers finished an interim stage on the replacement of Scotland’s

There’s an understandable tendency to focus our attention on the big high-gloss schemes with budgets measured in billions, but strategic benefits are delivered every night of the week through the efforts of a workforce that rarely gets the credit it deserves. Key commissioning milestones are often concentrated around bank holidays and yet, despite the heightened risks, early May saw a successful possession hand-back rate of 98.9%, whilst Easter hit 99.6%.

There was a major injury near Wickford, Essex, when a MEWP basket was struck by an RRV attachment, causing an operative in the basket to suffer a broken leg. Rail Engineer extends its best wishes to the casualty and hopes for a speedy recovery.

But the fact that such incidents are worthy of reporting is a reflection of how thankfully rare they are.

For all the stick the railway gets, it does so much right so much of the time.

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CAREERS

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Rail Engineer | Issue 190 | May-Jun 2021

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CAREERS

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This is an exciting opportunity to integrate into City & Guilds, a world class organisation and support with our purpose to ‘enable people and organisations to develop their skills for personal and economic growth.’

For more information and to apply: email:

hr@intertrain.biz

apply online:

intertrainjobs.co.uk

call:

01302 815530

Trainee Trainer /Assessors We are also recruiting for Trainee Trainer /Assessors for those who want to further their career in the rail industry.

Applicants with no formal training / assessing qualifications will be considered if they have a technical background in OLE, S&T or P-way engineering.

Rail Engineer | Issue 190 | May-Jun 2021

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Siemens Mobility is shaping the future of UK rail By promoting passenger-friendly mobile app solutions for public transport such as Mobility as a Service (MaaS) and allowing the passenger the convenience to plan, book, pay and travel from their smart device, Alex is helping increase the appeal of sustainable public transport. siemens.co.uk/sustainablemobility