14 minute read
ERTMS on the East Coast Main Line
CLIVE KESSELL
ERTMS
on the East Coast Main Line
The decision to resignal the southern end of the East Coast Main Line (ECML) has been well publicised. It is to be part of the Digital Railway initiative, although ERTMS (European Rail Traffic Management System) and its ETCS component (European Train Control System) have been around much longer than the ‘Digital Railway’ banner.
ERTMS has been in development since the late 1980s and ETCS has matured into a reliable product which is being adopted right across Europe and beyond. In Britain, it is deployed on the Cambrian Line, commissioned in 2010, on the central core of Thameslink in London including an Automatic Train Operation (ATO) overlay - a first in the world - and shortly on the Great Western Main Line from Paddington to Heathrow Airport, facilitating Crossrail and Heathrow Express operation.
So what is special about the ECML? This will be the very first UK main line to be equipped over a considerable distance and where conventional lineside signals will be removed once all operational and technical elements are fully proven. With the technology now robust, just why is this a significant project? Rail Engineer had a conversation with Toufic Machnouk, the Programme Director for the scheme, to find out. Project extent
ETCS will be deployed from King’s Cross to Stoke Tunnel, just short of Grantham, a distance of 106 miles on the main line East Coast route. Included within this will be the branch from Finsbury Park to Moorgate in London (mainly in tunnel), the Hertford loop from Alexandra Palace to Stevenage and along the Hitchin-Cambridge line as far as Royston.
The main line is mainly four-track but with a twotrack section over Welwyn Viaduct and the two associated tunnels, and a mix of two and threetrack sections from Huntingdon to Peterborough. The branches are two tracks. Nine tunnels are located between King’s Cross and Stevenage, including those on the Moorgate branch, and there are two tunnels on the Hertford loop. Level crossings exist north of Peterborough.
As such, all the challenges of a mixedtraffic railway built in the Victorian era will be encountered.
Preparatory work
The route equates to the control areas of the King’s Cross and Peterborough power boxes which were commissioned in the 1970s. Now nearly 50 years old, replacement is due with the York ROC (Rail Operations Centre) being the chosen centre to control the future railway.
This presents the first challenge. Before ETCS can fully take over, the old signalling has to be kept operational but without the need to install ETCS screens in King’s Cross and Peterborough. The solution is to transfer control of the relay rooms and other lineside signalling elements up to York.
In parallel, the approaches to King’s Cross station are being extensively remodelled which will be complete this summer. It made no sense to modify the existing panel for the new layout so all of the King’s Cross PSB area is mainly now recontrolled from York, leaving just the King’s Cross station area under the control of the old box.
A new WestCAD system in York will control the revised layout, together with four new Trackguard Westlock interlockings for resignalling of the Holloway and King’s Cross areas; York will then take over and King’s Cross PSB will close. The transfer of the Peterborough area of control will similarly take place in the latter stage of Control Period 6. The data links to enable all of this to happen are provided by the high-capacity FTN network under the control of Network Rail Telecoms.
ETCS elements
The ECML project will use ETCS Level 2 technology, meaning a continuous radio link to all trains using the present GSM-R infrastructure (more of which later) with fixed block sections to keep trains safely apart. Initially the lineside signals will be retained as changing over from conventional signalling to in-cab signalling in a single stage is not practical from either an operational or technical consideration. Eurobalises will be installed between the rails to give positional references. Under Level 2, conventional train detection equipment is retained (track circuits or axle counters) and the balises will be aligned to these sections.
Train control will be by means of Movement Authorities (MA) displayed in the ETCS cab unit together with a target speed indicated on a circular band within the display. Should the driver exceed the target speed, braking will automatically occur until the speed is within the allowed limit. All trains under the control of ETCS need to be equipped with the on-board EVC (European Vital Computer), the driver’s control panel, the Eurobalise reader mounted under the train, an odometer to measure distance from each balise and the GSM-R data radio to receive the radio-borne MA instructions.
PHOTO: JONATHAN WEBB
PHOTO: JONATHAN WEBB
ETCS equipment on the Cambrian Line where the system was commissioned in 2010.
King’s Cross PSB will close when control of the station area is transferred to York ROC.
PHOTO: NETWORK RAIL AIR OPERATIONS
PHOTO: FOUR BY THREE
ETCS still requires a computer or relay-based interlocking for the safe setting of routes and junction control. Most of these will be at the junction or station locations, with their SIL4 routesetting information connected back to the ROC. At York, between the control centre screens and the radio link, is a Radio Block Centre (RBC) that interprets the requirements for the ongoing route and translates this into a Movement Authority (MA) that is sent to the train.
Rolling stock fitment
Although non-fitted trains can continue to use the route providing the lineside signals remain, the ECML plan is to have these removed as soon as possible after the ETCS commissioning. As such, all trains operating on the route must be fitted. The LNER Azuma fleet, the new inner suburban Class 717 and the Thameslink Class 700 trains are already equipped. Other passenger trains using the route such as the Class 365 and 387 EMUs will be retrofitted. The Open Access Operators, of which there are two - Hull Trains and Grand Central - will need to conform; the former now uses Class 800 trains (similar to the Azumas) which are already fitted and Grand Central has completed a retrofit for their Class 180s.
For freight, a contract has already been let to retrofit the entire fleet of 20 different classes of locomotive; the ‘first in class’ design is underway. The most numerous of these are the Class 66, with the first being prepared for fitment in 2022. By the time the first section of ECML comes to the point of removing lineside signals, around 200-250 freight locos will be fitted, sufficient for ECML requirements.
There is also the considerable number of yellow plant machines and the intention is to fit enough of these to make a captive fleet for the line.
Finally, consideration has to be given to special and heritage trains that will occasionally operate. Under the banner of a ‘Pathfinder’ project, a design is being undertaken for ETCS fitment which will be tried out on the Class A1 Pacific ‘Tornado’ and designs developed for both a Black Five steam engine and a Deltic diesel that were the mainstay of the route during the 1960s and 1970s. Part of the project will be to assess the technical viability and likely cost which will determine whether ongoing work for heritage locomotives is practical.
Devising the deployment strategy
Changing to ETCS operation will enable a completely different approach to operating the railway for drivers, controllers, station staff, operation planners and the entire railway management layer. This necessitates a substantial change programme, with drivers representing the biggest area and the largest group of people. A mixture of simulator and overlay training on the real railway will be employed.
Simulator provision has been in place for some time and covers train operation, data input and log in, alarms and fault finding, electric and diesel operation with changeover for bi-mode trains, emergency procedures, wheel slip/slide and sanding operation, GSM-R radio operation and DAS (Driver Advisory System) where fitted.
Simulator suites exist for LNER at King’s Cross, Leeds, Newcastle and Edinburgh. Other TOCs are also investing in simulators, with all of these being used to support the project development including modelling and driver behaviour. Simulation can also be achieved by downloading the system onto laptops and tablet computers, enabling drivers to practice in mess rooms or their own homes.
So far so good, but simulators are not the same as the real thing. Initial deployment will be on the Finsbury Park to Moorgate section as this is almost a self-contained railway, with only a single class of train (the 717 fleet) using the line. Southwards from Drayton Park, the line is in twin tunnels necessitating the use of radiating cable to provide the GSM-R connection from track to
PHOTO: FOUR BY THREE
train. The existing tunnel signals will be retained until the drivers of this inner-suburban service are fully trained; they will be removed thereafter. The timing for the migration start is Quarter 2 of 2022, with the commencement of signal removal later in 2023.
More important is getting a section of the main line equipped with ETCS as soon as possible. The chosen section is from Welwyn to Hitchin, a distance of 18 miles. Once this is operational, trains then fitted with ETCS will be able to log in and log out of the system to practise the routines and gain familiarisation of the Movement Authorities. This is designed to allow for progressive migration to ETCS operations as more drivers are trained, at which point they can operate in ETCS mode on this section. The overlay allows for this to be achieved during appropriate operational times, similar to how driver training is carried out today.
Once sufficient training has been accomplished, extending ETCS operation north and south of Hitchin and Welwyn will be carried out in sensible stages, the details of which are still being planned. Going north of Sandy will require the recontrol of Peterborough box to have been completed.
Other technical considerations
ETCS in itself will not bring all the potential benefits of a modern digital railway. ETCS is only one-third of the total ERTMS concept, the others being the GSM-R radio link and ETML, the European Traffic Management Layer. The latter has never developed as a standardised system, proprietary designs of TMS having emerged in recent times.
Traffic management is important for congested areas where the correct routing of trains through complex junctions is critical to timetable adherence. TMS was found to be necessary for the Thameslink central core in order to achieve the optimum priority for train progression, especially during times of even minor disruption. The ECML is not so critical in this respect, but proposals are being developed as part of the overall performance improvement within York ROC. Simulation modelling will be carried out later this year.
Similarly, Driver Advisory Systems - ideally linked to TMS - will give optimum speed profiles to drivers even if the Movement Authority permits a higher speed. The Azuma fleet is already fitted with DAS and some freight fleets are also equipped.
Robust radio coverage is essential for reliable ETCS operation. When the GSM-R network was introduced, it was primarily for voice communication between drivers and signallers. As such, the basestation spacing of roughly every five miles was sufficient to give continuous coverage, but knowing that one failed basestation would not be too disruptive. Once the system began to carry data traffic of which ETCS is easily the most important element, coverage may need to be enhanced such that a failed basestation would not stop ETCS data exchanges from happening. Radio surveys are being carried out on the ECML to see if additional basestations will be needed.
The GSM-R radio system has been in existence for over 20 years and uses a 2G technology. The radio world has moved on and 4G systems are now commonplace, with 5G rapidly gaining acceptance. The new FRMCS (Future Railway Mobile Communication System) is well underway in the development stage as a European standard and is expected to begin trials in 2024/5, with system changeover expected to begin shortly afterwards. GSM-R is guaranteed to be supported until 2030 so initially the ECML can use this with confidence in the short term. Planning must commence shortly as to how a changeover will be accomplished without impacting on ETCS operation. LNER's Azuma fleet is already equipped with ETCS equipment.
Peterborough is an important junction where passenger trains from Cambridge/ Norwich and freight trains coming from Felixstowe cross underneath the ECML on their way to Birmingham and the northwest. Northbound freight traffic may also be routed on the line towards Spalding and Doncaster to avoid congestion on the ECML for which the Werrington diveunder is currently being constructed. It is likely that many of the services traversing this important junction will not be ETCSfitted. Peterborough will therefore have to retain lineside signals on some lines for the foreseeable future. Details of the precise requirements are being worked out.
Supplier co-operation
Siemens Mobility will supply and install the infrastructure components of ETCS in conjunction with Network Rail engineers. Testing and commissioning will be a joint exercise.
Fitting the trains will be the responsibility of the particular TOC who will likely select the prime manufacturer of the train to acquire and install all the components needed. This is where interoperability is important as any approved supplier of ETCS equipment can provide the piece parts in the full knowledge that these will function correctly across the air gap. A testing programme will be required to verify this.
Any enhancements needed to strengthen the GSM-R coverage will be carried out in partnership with the original supplier. Siemens Mobility at their Poole site will be supplying the on-board data radio as part of their contract to provide new cab radios across all TOCs. These radios are future-proofed to provide 4G or 5G connectivity whenever the replacement for GSM-R is progressed, thus negating the need to change-out train radios.
The business case
It has taken a long while to get this project approved and started. Whilst renewal of ageing signalling equipment has been a factor, the benefits of changing to cab signalling needed to be quantified. The cost of adopting ETCS - including all the elements of training, new operational rules, train fitments and such like - was greater than piecemeal renewals on smaller sections of the railway. However, the benefits of having continuous data communication yielding much-improved regulation of trains, the opportunity to optimise braking curves for different types of train and the ability to give advanced information on level crossing activation eventually won the day.
The ECML project cost is estimated at £1.8bn over an 8-9 year period, with much of the expenditure being front-end loaded for fleet fitment and change to enable the progressive infrastructure roll out.
With the advantages of ETCS accepted, future projects will be based upon the need to do signalling renewals. The ability to dispense with lineside signals permits significant savings to be achieved because of lower infrastructure costs. For the ECML, no firm plans yet exist for going north of Stoke Tunnel to cover the Doncaster power box area, but no doubt these will emerge before too long. Future ETCS prospects and plans
Despite the earlier ETCS deployments, it is the ECML project that will be the scene setter. Network Rail has already indicated some routes that might follow - the south end of the Midland Main Line, the West Coast Main Line in the WarringtonWigan area and parts of Anglia. These will sensibly fit in with signalling renewals and the availability of fitted rolling stock. A national rollout programme can be expected in time.
But is that the end of the story? Level 2 has acknowledged advantages but still requires the retention of track circuits or axle counters, both of which are expensive to provide and need on-track maintenance. The long-awaited ETCS Level 3 would do away with these devices and further simplify the infrastructure, as well as facilitating moving block to enhance capacity. The constraints are well known, proving train integrity being one of them. The ECML team are aware of this and are giving thought on how to adopt the Hybrid Level 3 idea since this will optimise the ETCS area and allow further improvement to operation for trains that are suitably equipped whilst retaining existing axle counters for others. A full description of this option was given previously in Rail Engineer (Issue 151, May 2017).
Thanks are extended to Toufic for explaining the project and its engineering detail. He has been in post since 2017 and we wish him well with the ongoing programme.
