Newcastle exhibition marks bicentenary of Robert Stephenson's company

DAVID SHIRRES

23 June sees the bicentenary of the founding of the world’s first locomotive works - Robert Stephenson & Co, in Newcastle. To mark this, an exhibition is being held in the Map Room, Neville Hall, Newcastle which is close to the station. This is open up to 25 March and has been organised by the Robert Stephenson Trust.

with young Robert’s abilities and so the 19-year-old Robert became the company’s managing partner when it was founded in 1823.

Its first locomotive, Locomotion, was built for the S&DR’s opening in 1825. This was assembled on the track bed by the future site of the Hitachi plant at Newton Aycliffe. Six tons of the various bits that made up the locomotive were delivered there from the Newcastle workshops on horse-drawn wagons.

In 1829, the company built an experimental locomotive, Rocket, for the Rainhill trails on the Liverpool and Manchester Railway. This had several innovations including a multi-tube boiler, fire drawn by a blast-pipe exhaust, and cylinders directly driving the wheels, and became the template for almost all future steam locomotives. Rocket won the Rainhill trials at the then unprecedented speed of 30mph.

The company’s workshops were established at Forth Street in Newcastle and continued to lead the development of steam locomotives. A particularly important innovation was the Stephenson link valve gear which can vary steam cut off into the cylinder, enabling a small amount of steam to be used expansively and so significantly improving efficiency.

By 1899, the company had supplied around 3,000 locomotives. To expand its operations, it opened an additional works in Darlington in 1902. By this time most UK railway companies built their own locomotives so most of the company’s output was for export.

In the 20th century there were various mergers and, with the decline of the British locomotive industry, locomotive building at the company’s Newcastle works ceased in 1961 and at Darlington in 1964.

The remarkable achievements of Robert Stephenson and his company make this bicentenary exhibition well worth a visit.

Robert Stephenson was born in 1803 and, at the age of 16, became an apprentice mining engineer at Killingworth Colliery. In 1822 he spent six months at Edinburgh University to study the properties of gases with the aim of improving the design of steam locomotives. He then had to help his father George with the construction of the Stockton and Darlington Railway (S&DR) for which, having surveyed the route, he was the designated engineer.

At this time, George Stephenson suggested the formation of a company to build locomotives for which he felt there would be considerable demand. The S&DR directors were impressed

There has been much criticism of the ride comfort of the most recent trains brought into use on the British rail network such as the class 8XX Inter City Express Trains (IET). Critics compare them unfavourably with older trains which, they say, deliver a superior ride. When travelling around the UK in 2022, your writer particularly noticed that IETs sometimes rode well and sometimes were extremely rough, so this is probably not entirely a train issue. Critics have also complained about uncomfortable seats (Issue 176 - July 2019), and these are clearly part of the perceived problem.

Passengers’ perception of ride comfort arises from a combination of their reaction to the accelerations they feel in three dimensions, and other issues such as noise and temperature. Ride comfort may be more subjective than objective, but there continues to be research to understand the contribution of the various factors to a ‘comfortable ride’ – vertical, lateral, longitudinal accelerations and jerks, together with noise. Illustrating this with one scenario, which does the passenger perceive as worse – general disturbance of the vehicle traversing points at speed or the same with much clattering from somewhere underneath the vehicle? This article is in three sections. First, a case study of a 30-yearold fleet that was criticised for a poor ride when new but was improved; second, exploring some of the factors that might explain why we achieve a less good ride on modern trains compared with, for example, those in the case study; and third, what can be done to improve the new trains.

Case study: Mark 4 coaches

Mark 4 coaches were built by Metro-Cammell in the late 1980s and featured SIG type BT41A bogies. In service, the fleet was criticised for poor ride. British Rail management of the day accepted the criticism and determined that something needed to be done. As far as Rail Engineer is aware, the specification/requirements had been complied with, but it was clear from contemporary commentators (Roger Ford et al) that the ride was not good at 125mph, although there were reports that all was fine at the specified 140mph. Investigation involved measuring accelerations using tri-axial accelerometers and recording equipment (such as is used for measuring the ride comfort of IMechE Railway Challenge locomotives) at various locations along the vehicle floors. This equipment is simple and straightforward to use. The analysis of the data indicated two problems.

First, there was a great deal of relative lateral movement between coaches especially noticeable if negotiating the inter-car gangway. This was the first time that the two halves of the gangway were physically connected and there were no friction-mating faces that would have provided a level of friction damping. The problem was resolved by fitting a transverse hydraulic damper underneath the gangway with one end connected to one coach and the other end to the next coach. The damper also improved the overall lateral ride.

Second, it was found that the yaw dampers mounted on both sides of the bogies were exciting the first vertical body bending mode. This is illustrated in the diagram showing the original orientation of the dampers as a red line and the body bending represented by the yellow dotted line. Engineers investigating this believed that if the damper mounting location could be changed slightly, the problem would be reduced or rendered ‘mostly harmless’. The agreed modification was for the bogies to be turned though 180 degrees, meaning that the yaw dampers faced toward the coach centre rather than the end (the green line on the illustration). With the support of the supplier who had the models, the solution was ‘tested’ using vehicle dynamics multi-body computer modelling and shown to be effective. Simulations are often part of the solution, and they can really only be done by the supplier, the organisation that understands how the suspension works, the detail of which is key to effective simulation.

It was necessary to reposition the yaw damper body mounting bracket from the outer to the inner side of the body bolster, a comparatively straightforward modification. This is the configuration that will be seen on the remaining mk 4 coaches in use today, although observers will note that the shorter Driving Van Trailers retain the original yaw damper layout as they react to the yaw damper differently from the longer passenger cars.

Why do we achieve a less good ride today?

There are three main reasons: compliance culture, organisational complexity, and lack of a guiding mind.

Compliance culture

Engineers ‘of a certain age’ often say “standards are for the guidance of wise men [appropriately dating the saying] and the blind observance of fools.” These days it is apparent that demonstration of compliance with the requirements (procurement specifications, National Specifications, Standards etc), is all that’s required. Requirements are generally SMART - Specific, Measurable, Achievable, Relevant, Time-bound –whereas aspects such as seat and ride comfort are subjective.

As an example, the original UK Government IET specification called up sections of line on which a specified ride quality was to be achieved (although, curiously, this included a section where the trains were not required to operate).

The various specifications and standards permit the ride quality requirements to be demonstrated by simulation, as providing a track for physical testing that actually meets that specified at procurement is fraught with its own issues. This begs the question whether simulation adequately replicates all the factors involved in delivering ride comfort (see panel). But can it be said that this fully replicates what the passenger experiences? Does simulation model seats and noise paths, for example?

Organisation complexity

In the case study above, there were just two parties: British Rail and Metro Cammell. By comparison, the original IET contract involved the following players:

» Specifier and Procurer: Department for Transport

» Supplier: Hitachi

» Owner: Agility Trains

» Infrastructure Manager: Network Rail

» Operator: LNER and GWR

Along with these were a number of roles provided by one or more independent organisations (often procured by the train supplier) to certify compliance with:

Technical Specifications for Interoperability (as was the regime of the day) – Notified Body; Notified National Standards – Designated Body; and Common Safety Methods (risk evaluation and assessment; monitoring; safety management system requirements; supervision; common safety targets; conformity assessment)

– Assessment Body.

Which of these organisations feels the pain sufficiently to commit management time and funds in order to investigate and deliver a fix? One can imagine the operator going back to the supplier, being told that the train is good as it has been independently certified as compliant with requirements, pointing to a possible track problem. Conversely, an approach to Network Rail will show that its track is consistent with the specified quality. Inevitably a multi-party investigation is required but, with the current contract structure and financial constraints, is anyone likely to be able to get permission to fund the investigation, let alone any modifications?

A multi-party investigation did take place with the IET bolster/ lifting pad cracking issue, and it seems that the parties only come together jointly to resolve a problem when there is a safety issue.

Lack of a guiding mind

In BR’s day, one of the guiding principles of the organisation, certainly by the late 1980s, was delivering quality for passengers. This would have infected the culture of the place and, when the issue with the Mark 4 coaches was identified, one can imagine that the InterCity director of the day would simply have told the project engineer to sort it out, although remembering some of the engineers involved, they were probably already on the case. The project engineer would have involved the train supplier and the track engineers and would have been able to rely on the support of BR Research experts. But who would do it today? One might expect the train operating company (TOC) to be the organisation that wants to delight the passenger but even prior to Covid, when franchising contracts were still recognisably revenue/profit driven, the TOCs concerned were not in the driving seat. Their contracts effectively said that they would operate the trains that had been purchased and approved for them. They were unable to influence seat comfort, for example.

What could be done?

Part of the cure is to acknowledge that the best simulations in the world and compliance with standards only get you to the starting gate. When the train starts running on the track, reports of poor ride, from staff or passengers, need to be taken seriously – an acknowledgement that something is wrong. From there, work can proceed to diagnose the problem. This would probably start with the same measurement methods that were used on the Mark 4 coaches. Only when that data set is available can engineers start to understand what is causing the poor ride and what might be done about it. It might be that the train is sensitive to particular track features and some work on the track might be cost-effective. Equally, a train fix could be as simple as tweaking damper rates. The information would also help to understand why the simulation did not predict the problem, for instance if there was a deficiency in the specification or that someone made a mistake.

Another simple improvement would be to make the seats more comfortable at the first occasion when they need recovering. It is possible to have comfortable seats on these trains; those on the Lumo trains seem to be well regarded, for example.

The question is whether there’s any possibility that this will be done? Even the outline proposals for Great British Railways (GBR) are unclear whether it will be GBR itself or its contracted operators whose role it will be to delight passengers and hence have the incentive to make improvements to passenger comfort. But, if the aim of GBR is to re-unite the wheel and the rail, we could argue that part of the demonstration of a good wheel/rail interface is passenger comfort.

University of Huddersfield's THOMoS ride assessment rig in operation.

Conclusion

While this article sets a fairly gloomy tone, there is hope for the future. We have already seen complaints about ‘ironing board seats’ prompt research into objective ways of specifying seat comfort, albeit still with a level of subjectivity involving a passenger assessment process. The standard on ride comfort, EN12299, provides tools and methodology to investigate ride comfort issues when applied in an appropriate way.

One also hopes that University of Huddersfield’s work with THOMoS (Issue 195 - March/ April 2022) will lead to better understanding of the impact of particular track/suspension interactions on passengers’ perceptions of good and bad ride, and that suitable requirements can be framed to achieve better results.

Panel

There are a lot of elements that contribute to ride comfort: track geometry; wheel profile; primary suspension (springs/ dampers/bushes); bogie stiffness; secondary suspension (vertical and lateral); yaw dampers; body stiffness and bending modes; inter-vehicle effects (longitudinal coupling stiffness and yaw between vehicles); anti-roll bars; traction and braking jerk control; and noise paths.

A smooth stable ride can only be achieved through careful optimisation of all the components between the track and the passenger’s feet or buttocks. Vertical, lateral, longitudinal, yaw and roll all work towards this objective. But there are often competing objectives (staying within gauge for example) that prevent the designer simply optimising the suspension for the best ride.

If the track is smooth, the train’s suspension has an easy time. If the track is less smooth, a good ride can still be achieved but softer springs might be required. But softer springs bring more suspension movement which might mean the body has to be a little smaller, which, in turn, might affect the accommodation. Softer springs in the vertical direction lead to more roll on curves, and anti-roll bars might be provided to control roll, particularly on vehicles where pantographs are fitted. But anti-roll bars can also introduce a transmission path for noise and higher frequency vibrations if the selected bushes are not perfect.

Computer simulations to demonstrate vehicle safety and stability are sophisticated but inevitably they do not take account of absolutely every factor and do not account for noise transmission at all. Car bodies and bogie frames might be assumed to be rigid, for example. Yet, as the case study explains, car bodies are flexible, and this can affect ride with longer vehicles tending to have lower bending frequencies more likely to be detectable by passengers. Depending on exactly where attached, component mounting points can have an impact on the overall ride performance.

Finally, ride quality is a system property and not determined by the train alone.

The

Malcolm Dobell I

n Rail Engineer 184 (May/June 2020), Paul Darlington described the upgrade of the Merseyside rail network in and around Liverpool, which involved new trains, upgraded infrastructure, power supplies and depots, together with a network wide train-infrastructure Wi-Fi system. To recap, MerseyRail is the largest third-rail electrified network outside London and the South East, has extensive underground running and is largely self-contained. Pre-Covid, the network carried 110,000 passengers on weekdays and a total of 34 million passengers per year along its 75 miles of route with 68 stations.

Six stations and 6.5 miles of route are underground. It is also unusual that, since 2002, the Liverpool Region Combined authority, through its Merseytravel arm, is the franchising authority for the network. It is currently operating the oldest fleet of any main line operator in the country but is on the cusp of a transformation. During a visit to Kirkdale depot in November 2022, David Powell, Merseytravel’s Project Director, briefed Rail Engineer about the Class 777 trains and the various system changes to enable their operation prior to the first train entering service which took place on 23 January 2023.

Before describing the trains, it’s worth remembering the benefits that were identified at the start of the programme in 2012:

» Improved safety, especially at the platform train interface having regard to the James Street fatality in 2011

» 10% journey time reduction

» 50% higher passenger capacity to meet rising demand

» Improved passenger facilities

» Future-proofed to operate beyond third-rail infrastructure

» The most accessible heavy rail network in the UK

» More reliable than Class 507/8

» Reduced operating and maintenance costs

» Reduced carbon footprint

Liverpool was in a position to fund the new trains for itself without recourse to a ROSCO. This allowed Liverpool to specify a train solely to meet its own needs without needing to think about residual value issues. The resulting finance model uses the council’s own reserves plus loans from the Public Works Loan Board and the European Investment Bank (one of the last loans to UK following Brexit).

Bespoke solution

Following competitive tendering in 2016, Stadler was selected to design and manufacture the trains and it was also decided to contract Stadler to maintain the trains - Stadler’s first maintenance contract in the UK. One of the benefits of choosing Stadler is that it specialises in bespoke solutions and Liverpool’s is a completely new design. Initially 52 x 4-car, 65-metre-long units were procured with an option for up to another 60. Since then, one additional train has been ordered. The rolling stock design was completed in 20 months following extensive interaction with passengers to determine key interior design features. David Powell described them as “Metro style units designed to mainline standards”. Bodyshells are made in Hungary, bogies in Spain, with final assembly in Switzerland and Poland. Dynamic testing was carried out at the Siemens facility in Wildenrath, Germany. The first unit was delivered to the UK through the channel tunnel in January 2020. Not all the trains have yet been delivered to Liverpool which will be explained later in the article.

David said that right from the beginning and throughout the design process, customers were invited to express their desires for the new trains in work carried out by the research arm of Transport Focus. One key passenger requirement was for level access from platform to train in order to allow people with wheelchairs, buggies, and other mobility impairments to board and alight easily. This led to an early design decision to lower the floor from the usual 1100mm (approximately) to 960mm and use extending panels to bridge the gap between train and platform. These have ultrasonic sensors fitted which stop the extending panels approximately 35mm away from the platform edge. This and other features meant that a number of infrastructure changes were necessary which are covered later.

Features

The train’s outline specification can be seen at the end of the article, but notable features include open wide gangways throughout the unit, air conditioning, 240V 13A & USB sockets at every pair of seats, and line maps displayed on LCD screens. Research indicated that customers like to know that the security CCTV is working, so images from the saloons are also displayed on the LCD screens. On each unit, there are two storage areas for three bicycles. The cab design is unique. The nature of the tunnels is such that there needs to be a means to evacuate passengers from the front of the train. But there was also a desire to improve sightlines for the driver which meant larger windscreens compared with the old trains. So, unlike the old Class 507/8 units, rather than in the centre of the cab front, detrainment is via a sliding plug door fitted on the right-hand side. This is accompanied with an angled ladder which runs from this doorway to the middle of the track (a straight ladder might have ‘landed’ right above the conductor rail). In the event that a train-to-train detrainment is required, clearly the detrainment doors will be on opposite sides of the coupled units, and for this a series of platforms and barriers are deployed to provide a safe gangway.

Each passenger door is monitored by its own external CCTV camera and two monitors, each displaying views from four cameras, provided in the cabs. It is planned to operate the trains with the driver controlling the doors and a train manager will look after the customers and perform a platform check at stations.

For maintenance, Kirkdale depot has been extensively modernised. With pit roads and highlevel platforms to access roof mounted equipment (antennae, air conditioning packs, dynamic brake resistors, etc). In passing, the end cars have panelling on the roof to smooth the flow of side winds over the body. Modelling had shown that there was a risk of overturning in the presence of side winds specified by standards. This was not a risk on the shorter intermediate vehicles. David said that he hopes, in time, to justify their removal as they are an impediment to maintenance. The depot has three-phase shore supplies to power the units’ auxiliaries, but movement in and out of the sheds is powered by the train’s limited movement batteries.

Bemu

Merseytravel has ambitions to extend the MerseyRail network, and, with ORR ‘presuming against extensions of third-rail systems’, provision was made on the trains for 25kV supply or batteries with space under each end car. At Rail Live 2021, Stadler demonstrated a prototype battery-powered Class 777 unit with batteries weighing 2.5 tonnes. This was used to explore practical range on the Liverpool network, resulting in Merseytravel varying the order to increase the order to 53 trains, seven of which will have three tonnes of batteries on each end car, together with an additional power converter (increasing the tare mass by approximately 6%). The batteries will be Lithium Titanate Oxide type with a total capacity of 320kWh. These give a good combination of energy and power density and have an inherent resistance to thermal runaway. The initial offthird-rail section will be a one-mile extension from Kirkby to a new station at Headbolt Lane, but David says that there is an ambition to extend to other locations such as Wrexham. The first production Class 777 BEMU delivered an encouraging 135km range which shows what is possible.

Infrastructure

Having resolved to have lower train floors, clearly the platforms needed to be compatible. The aim was to deliver platforms at or close to the standard 915mm height and 730mm offset. David reported that 92 platforms at 56 stations had to be modified for height, offset, or both. This programme was managed by Network Rail, and David praised the way the work was delivered on time. In general, the work was carried out in line blockades with a number of platforms being tackled simultaneously. Other changes, including moving signals at the ends of some platforms, are being undertaken. To satisfy the ambition to run 8-car, 130-metre trains, some platforms and the turnback siding in the underground section at Liverpool Central need to be extended.

Power supply

At 2100kW peak power output at the wheels, the new trains demand about three times the power of the existing train. The power supply was upgraded to address existing volt drop issue and to raise the maximum current draw from 4000 A to 5400 A. This was achieved by providing three new bulk supply points (from the regional electricity company to the railway), eight new substations and extensive cable upgrades.

Wireless connectivity

The last element of the upgrade is the wireless connectivity system. David said that the business case for upgraded comms was based on: obtaining data from the trains to enable predictive maintenance; reducing workload on the drivers; ability to access both live and recorded CCTV both in the operations and British Transport Police control rooms; to update passenger information in real time; and to send emergency alerts to the Sandhills control room (where Network Rail, MerseyRail, and Stadler personnel are colocated). It was these features that gave a positive business case but, as a by-product, customers get access to on-train Wi-Fi too. The technology is Wi-Fi throughout, rather than the more usual on-train Wi-Fi connected to the infrastructure via 4/5g mobile modems. Panasonic is providing the system and David mentioned the 120km of trackside cables that have had to be installed.

Introduction into service

As described above, fleet introduction, initially on the Kirkby line started in midJanuary 2023. From there a complex cascade starts. With 59 old trains, 53 new ones, and only 70 unit stabling/siding spaces, David’s extended project team has prepared a detailed plan to manage hand back of the old fleet to Angel Trains (Class 507/8 ROSCO) whilst training all the staff who will interact with the new trains, bringing more and more trains onto the network and ensuring that fault free running has been completed, whilst managing

Class 777 features

» Four-car articulated unit.

» Bogie arrangement: Trailer – motor - motor –motor – trailer.

» Lightweight carriage body made of extruded aluminium profiles.

» Newly developed motor trailer bogies with internal bogie frames, pneumatic suspension and wheel tread friction brakes; motor bogies under articulated joints.

» Modern vehicle control system.

» Automatic front coupler for multiple operation.

» Plug sliding doors and sliding steps for level entrance.

» AWS/TPWS/tripcock train protection and Automatic Selective Door Open system.

» Prepared for later retrofit of ETCS and 25 kV power supply equipment.

» Train batteries allowing depot movements independently of power supply; units are designed to allow later installation of much larger batteries, implemented on the 7 BEMU units ordered.

Comfort:

» Bright, passenger-friendly interior with an iconic design

» Six entrance doorways on each side for rapid passenger flow

» Level access at all entrances

» Spacious multifunction areas and wheelchair spaces

» Modern passenger information system and CCTV

» Powerful HVAC system the inevitable modifications that all new trains require, especially after being exposed to passenger operation for the first time. Finally, David paid tribute to the teams who have worked on this programme. Vital to the programme has been cross organisation teamwork including: willingness to share information, recognition of each other’s perspectives and, above all, compromise.

With thanks to David Powell, his assistant Jane Brimage, and to Stadler’s Alex Maher for their assistance with this article.

Personnel:

» Spacious cab with excellent driver sight lines

» Ergonomically designed driver’s desk

» Automated cab side doors for comfortable access

Reliability/Availability/Maintainability/Safety

» Three IGBT three-phase drive systems; one per pair of motors (ABB)

» Force cooled traction motors (TSA)

» Remote vehicle diagnostics to support condition-based maintenance

» Automated front bridging system for movement between units for evacuation

Supply voltage: 750 VDC

Number of units: 53 with options for another 59

Seats (one class only): 182 (Class 507: 192)

Tip-up seats: 8

Standing capacity (4 pers./m2): 302

Floor height: 960mm (Class 507: 1100mm)

Doorway width: 1300mm

Unit length: 64980mm

Vehicle width: 2820mm

Vehicle height: 3828mm

Bogie wheelbase: 2400mm

Wheel diameter, new: 760mm (similar size to Underground tube stock)

Power output at wheel: 1500kW [Continuous] (Class 507: 650kW)

Power output at wheel: 2100kW [Maximum] (350kW/motor)

Starting tractive effort: 162kN (up to 46km/h)

Starting acceleration: 1.1m/s²

Maximum speed: 120km/h

Tare mass: 100 t (Class 507: 104.5 t)