When Network Rail took over the national rail infrastructure in 2002, it inherited roughly 800 operational signal boxes deploying a wide range of technologies including lever frames, ‘entrance-exit’ (NX) panels and VDU workstations, built over a long period of railway history. The Stockport lever frames mentioned later in this article were opened in the 1880s!
With the age and reliability of the equipment causing concern, and Network Rail coming under increasing pressure from The Office of Rail Regulation (ORR) to reduce both operating costs and delay minutes, and to find yet more paths for an increasingly congested network, the National Operating Strategy (NOS) was devised. This sets out to improve capacity and performance standards, while at the same time cutting the day-to-day cost of running the railway.
Cornerstone of the project is the consolidation of train control to 12 Rail Operating Centres (ROCs) nationally. These will be the existing signalling control centres at Cardiff, Derby, Didcot, Edinburgh, Glasgow and Gillingham and new ones at Basingstoke, Romford, Manchester, Rugby, Three Bridges and York.
Network Rail recently opened the new ROC at Manchester. The Rail Engineer went along to hear Andrew Simmons, Network Rail’s technical director for the National Operating Strategy, explain the developments taking place. Jonathan Harris, London North West (LNW) route output integration engineer, was also present and described the way in which the route is implementing the NOS.
The first new workstation in this ROC, commissioned in July, controls the remodelled and resignalled line between Huyton and Roby on the original Liverpool & Manchester Railway.
This is a phase of the capacity improvement programme on the Chat Moss route to re- instate four running lines between Broad Green and Huyton Junction. Signallers use Siemens Controlguide Westcad MCR workstations to interface with Siemens Westlock interlockings. Automatic route setting (ARS) has not been provided at this stage, although the system is capable of interfacing with it when signaller workload would benefit from its provision.
Adjacent to the signaller’s workstation is the technician’s Westcad monitoring workstation, enabling the signaller to engage quickly with the technician in the event of any unexpected technical issue. A framework contract is in place with Siemens Rail Automation to provide further workstations and interlockings as the ROC progressively takes over more routes.
Over the next 20 years, all of the railway in the north-west of England will be controlled from the ROC, bordered by Crewe to the south, Todmorden in the east, Carlisle in the north and the Welsh border to the west.
An off-line signalling workstation simulator is provided in a separate room for signallers to gain familiarisation of track layouts that they will operate in the ROC. The simulation software is TREsim for Westcad, developed by TRE in conjunction with Siemens Automation to provide support for training and assessment of signallers working at a Westcad workstation. The timetable simulation includes the capability to set up incident scenarios.
Train and electrical too
In December this year, Network Rail, TransPennine Express and Northern train controllers will relocate into the ROC and work together in the same large open-plan office as the signallers. Traction electrical control is due to be included in 2016. When fully operational, up to 400 staff will work in the centre.
Jonathan Harris was keen to stress that the wellbeing of staff is paramount. A lot of work has gone into making it a pleasant place to work with the best possible facilities including break-out spaces and a gymnasium. Old photographs of heritage railway infrastructure add a link with past railway operations in
the Manchester area. The safety-critical nature of operations within ROCs is always a key consideration with all facilities provided throughout the building.
Morgan Sindall constructed the three-storey steel-framed building built at Ashburys on a brownfield site hitherto used for various industrial activities. A variety of specialist design and construction methods were used including laminated, strengthened glass panels and curtain-wall cladding.
The building is highly insulated, with a ‘green roof’ planted with sedum vegetation to absorb rainwater. Although it has been designed for resilience with blast-proofing, multiple power supplies and 24-hour security, consideration is being given to hand-over for continuity in the event of a high-impact event. It is not technically difficult, given IP-based links, to hook up controls to another building. However, one of the more difficult issues is ensuring suitably qualified staff are available to take over at an alternative location.
West midlands recontrol
LNW has a second ROC at Rugby which is currently under construction. Resignalling and recontrol in the West Midlands is gathering pace – the Walsall PSB (power signal box) closed last year whilst Wolverhampton goes later this year. Birmingham New Street and Saltley PSBs are scheduled for closure within the next three years.
As an interim measure, control is being transferred to the West Midlands Signalling Control Centre at Saltley. Built as a Network Management Centre for Railtrack’s ill-fated West Coast ‘Passenger Upgrade 2’ (PUG2) programme of 140mph running with cab signalling, the robust bomb-proof building is not re-configurable to suit the staffing requirements of a ROC.
Once the whole of the West Midlands hub has been fully recontrolled to Saltley, a business case will be prepared on the basis of the benefits that the ROC and Traffic Management will bring, at which time control will be transferred to Rugby with the Saltley building remaining to house the interlockings.
Physically moving the hardware of existing SSIs (solid state interlockings) from old control centres into a new ROCs incurs significant installation, test and commissioning costs. An alternative solution is the remote interface (RIF) to be installed alongside the SSIs at the old signalling centre, which then communicates with the ROC using a modern protocol that is fully compliant with the CENELEC standards for safety related communications. However, maintaining old buildings to house this equipment also incurs costs and a balance has to be struck.
Signal box to ROC
With nearly 500 signal boxes still left in service today, the migration to ROCs is determined by several factors upon which a business case is made on a route-by-route basis including:
» Remaining life of the signalling asset such as interlocking/panel/comms/ power supplies/cabling/signals/points/level crossings;
» Maintenance costs of keeping old signal boxes in service; » Head count reduction;
» Benefits of introducing traffic management (TM);
» Programme to fit European Train Control System (ETCS); » Introduction of Automatic Train Operation (ATO);
» Advantages of extending a larger area to get bigger performance benefits.
A key benefit of the ROC programme will be the introduction of a traffic management system. For example, with the creation of the Ordsall chord line enabling trains to run direct between Manchester Piccadilly and Victoria, it makes sense for this complex area to be controlled by one centre with
the benefits of TM to regulate what is already a challenge for signallers today, even though not all the signalling infrastructure is life expired. Thus the transfer of control from Manchester Piccadilly and Manchester North Signalling Centres to the ROC will result in significant efficiency gains and is planned for the next five years.
In contrast, the five lever-frames at Stockport and the Manchester South Signalling Centre have many years life left. The regulation of traffic in the Stockport area is unlikely to significantly improve with TM from that which is achievable today. Accordingly these boxes are scheduled for transfer to the ROC with full resignalling to a TM system in the late 2020s.
Another example is Merseyrail where the Sandhills IECC (integrated electronic control centre) and associated SSIs are not life expired and, as it is largely a self-contained suburban railway with limited benefit from TM regulation, the migration is expected to occur in the 2030s.
The locations and number of the ROCs were chosen by taking into account the best fit for efficient management of defined geographical areas of the network, availability of railway owned land, integration of Network Rail route controls with those of the train operators, proximity with the operational railway to facilitate running of cable routes, comms and data links, and places with good public transport and road access for staff.
Traffic management (TM)
Centralising control is nothing new. NX panels controlling large areas were built in the 1960s-80s and were staffed with signallers and ‘area controllers’ sitting at the back whose role was to oversee traffic movement and make strategic regulating decisions. Unfortunately, the full benefit of centralised control was never fully realised as, in the pre-digital age, the various departments involved in running the railway functioned in separate offices with limited inter- departmental communication.
That is about to change significantly. The functionality of the new TM systems will introduce an unprecedented degree of integration between railway departments.
A simple example will illustrate this. In GNER days, York was noted for trains standing at signals outside the station whilst the booked platform was occupied, despite the fact that other suitable platforms were available, thereby incurring unnecessary delay with repercussions of late running and reactionary delays.
GNER stated that it was not policy to make platform alterations as this inconvenienced the passenger, particularly those with heavy luggage. This argument doesn’t really stack up given that the signaller can anticipate such a situation some 20-30 minutes before arrival of a train and arrange for the platform alterations to be displayed in good time.
However, GNER did have a point. Neither Automatic Route Setting nor the signaller are empowered to unilaterally make platform alterations. Such a request has to be put to the Network Rail controller, then the train company controller, then the station dispatch team, and the response fed back the same way to the signaller by which time the train has probably already come to a stand outside!
Decision-making such as this requires data from a variety of sources: will the train fit the alternative platform? does the driver know the road? are the dispatch team resources flexible enough to cope? is disabled assistance needed? is there a catering trolley involved? will this platform be needed for another train which might be then be delayed? and so on.
This is where TM comes in. TM links together a wide range of data associated with managing the timetable, train dispatch, issue of movement authorities, network availability, incidents & delays and service information. It continuously monitors the running of the railway, highlighting the effects of timetable perturbation, and provides options to help minimise delays.
Managing incidents and delays
Whilst a lot of work goes on behind the scenes to ensure that infrastructure and trains are made ever more reliable, and the extent of delays from external causes such as fatalities and the weather is minimised, such primary delays cannot be totally eradicated. In response to these events, the TM system will enable the running of the railway to move away from a ‘reactionary’ or even a ‘non reactionary’ mode to fully proactive decision making. When an unplanned event occurs, TM allows planners to use a series of tools to choose the optimal solution to reduce reactionary delay minutes.
As signallers, technicians, train controllers are all in the same room, easy communication, bearing in mind relevant safety critical communications procedures, means the immediate decisions to re-route a train will be supported by all the relevant stakeholders. Even those not in the room, such as station dispatchers, will have access to the process via tablets/ smartphones. Once the planner has selected the most suitable option the TM will do the rest and instruct the interlocking to set routes according to the revised timetable plan.
When TM is introduced, the signaller’s workstation will become part of the TM pod, replacing the traditional ‘entrance-exit’ route setting interface. TM gives a 20 minute window for the signaller to make assessments before a revised plan kicks in as selected by the planner.
While TM can make immediate judgements to work around issues, it primarily takes a step back into timetable planning and allows the plan to be changed on the basis of a variety of data such as platform occupancy, train- set diagrams, when diesel trains need to be re-fuelled, crew rosters, drivers route knowledge and routes out of service. Algorithms will be developed and refined over time.
The business case and focus for TM is based on reducing reactionary delays by 20%. Additionally TM will help optimise network capacity and improve the accuracy of passenger information.
Key to achieving the TM business case is its conflict identification and resolution capability. As more ROCs are fitted with TM and linked together, so the benefits spread. For example, the right decision on whether to give priority to an on-time local stopping train and further delay a late-running Penzance-bound cross-country train at York may be taken after viewing the predicted outcomes on the rest of the network. At present, there is a tendency to give priority to trains running on time at the expense of those ‘out of path’ to minimise the visible Schedule 8 penalties.
Network Rail has selected the Thales ARAMIS (Advanced Railway Automation Management and Information System) TM system for installation at the Romford and Cardiff ROCs. Contracts for the national rollout of TM will be subject to future competitions and will involve all traffic management framework holders.
ARAMIS is already in service in other countries including Germany, Austria and Portugal. The system has been evaluated by a team of representatives from Network Rail and the train companies using the London-based Model Office with significant input from other industry stakeholders.The tools that TM presents to the planner can best be illustrated by some of the key screens used by the ARAMIS system. The Line Graph displays the track layout indicating train position, timetable deviation, set routes and planned route while the Train Graph is a real-time graphic function that shows planned, actual and predicted train paths and highlights future conflicts between trains, and between trains and possessions and other critical resources such as train crew.
Returning to earlier comments about platform allocation, the Platform Docker informs the user about actual and predicted arrival and departure times of all trains at a station as well as track usage, interconnection dependencies and conflicts. The Connection Graph shows the actual arrival and departure time of all trains at a platform and the relationship between trains such as between a terminating train and its next duty.
There is also an Incident Management Tool which allows a live view of the status of an incident to be viewed and updated, by those involved in managing the incident.
As well as controlling conventional signals, the ROCs will also interface with the latest and future on-board systems in the driver’s cab. The European Train Control System (ETCS) is one such system which is already being implemented.
The cab display shows movement authorities generated by the TM system via the safety interlocking. Network Rail has successfully simulated Level 3 (moving block) at the ENIF (ETCS National Integration Facility) test site. Capacity is a weakness of main line multiple- aspect signalling.
For example, when faced with yellow aspects, drivers brake the train in anticipation of a red light ahead. However the red may be due to a train ahead doing a station stop. Having made the stop, this train is now accelerating away. Even so, the following train will continue to slow down until the first train clears a signal overlap some distance ahead. Consequently, the gap between the trains has widened considerably.
With ETCS, each train knows exactly where it is and provides this information back to the control centre continuously. Hence ETCS Level 3 will permit trains to close up in a safe manner since there is no longer the constraint imposed by a fixed block system. The technically challenging issues are train integrity and ‘end of train’ position. This topic is currently the subject of research to develop a safe system. The initial East Coast ETCS fitment plan includes an option to fit Level 3 between Drayton Park and Moorgate.
Another train-borne system, Automatic Train Operation (ATO), receives movement authorities from TM via the ETCS system and calculates the optimum speed profile of the train. Already in use on several London Underground lines and the DLR, Network Rail’s first application will be on the Thameslink route by 2018. Siemens Class 700 trains will be fitted with ATO which is ideal for high capacity railways.
To help the driver keep to time, a driver advisory system (DAS) is fed with the working timetable for the train. It then calculates the optimum speed that will ensure the point-to-point timings of the timetable are matched by the performance of the train in a fuel efficient way. However, when connected via the TM system, the speed profile can be adjusted to take account of conditions ahead – availability of a path at a junction, or the platform at the terminus.
The system can also tell the driver when the train needs to reach a junction or station at the right time without having to stop and restart at a red signal, thereby clearing the junction more quickly and also saving fuel. It’s a double win. Connected DAS, which does not require ETCS, is being trialled at Airport Junction this year and will be rolled out to Thameslink and South West trains. All the exciting technological developments described above have tremendous potential to improve the efficiency of the railway and reduce delays in the years to come. Many traditional roles such as signaller and timetable planner may well evolve as the programme develops. Naturally, Network Rail sees staff and stakeholder engagement as vital for the success of the project but there is a great enthusiasm to get on with the programme and realise the benefits.
Thanks go to Network Rail’s Selina Clarke and Jim Lynch, NOS communications managers; Andrew Simmons, technical director for NOS; Jonathan Harris, LNW route output integration engineer; and Alex Tapsell, operations and interface manager. Mark Smalley, sales manager with Thales, and the evaluation team who demonstrated the Thales TM Model Office, were also invaluable for their help in preparing this article.