Signal engineers tend to have a measure of distrust when new ideas and concepts are put forward. This is understandable, given that any radical change to signalling practices can have catastrophic consequences if it all goes wrong and accidents occur.
It has taken over 20 years to develop and prove ERTMS/ETCS but, even now, the ultimate goal of Level 3 systems with no lineside signals and radio-based train detection seems many years away.
Nonetheless, progress has to be made with technology and engineering methods in order to drive down the cost of signalling, now measured by the terminology SEUs (Signalling Equivalent Units), a measurement based on the number of items controlled by the central interlocking.
Network Rail has had a Signalling Innovations Group (SIG) for a number of years and it holds a seminar annually to enlighten the railway community on the initiatives it is engaged in. Rail Engineer has reported on this event in the past, the last time being in 2014, so it was high time to take a re-look at what the group is currently engaged in and a meeting with the Group’s head, David Shipman, was held recently.
Group organisation and mission
Having national implications, SIG is part of the centralised engineering organisation within the IP Signalling project delivery organisation. The Group has a total of 18 engineering and support staff, based principally in Birmingham, Crewe and York but with outbased members in Glasgow, Derby, Milton Keynes and Reading. This will enable close contact with the soon-to-be-established Regional organisations, each of which will have its own signal engineers responsible for day to day performance.
Whilst much of the team’s work is an essential operational overhead, there was a budgeted programme of signalling innovations in Control Period 5 (CP5). For CP6, the group will work far more as an internal consultancy, winning the mandate for delivering specific packages of work. This has already borne fruit in establishing SIG as the deliverer of design tools elements of the research and development (R&D) programme for command, control and signalling (CCS).
Under the ‘putting passengers first’ devolution programme, SIG expects to become part of the national Network Services directorate, offering a key link between capital delivery in the regions and the central technical authority.
In line with the consultancy role and the need to maintain customer demand both internally and externally, SIG’s activities are regularly marketed by means of articles, external events and participation at national and international conferences. Interestingly, there is no one equivalent group in electrification & plant or building & civils, and only a smaller element in track, which perhaps demonstrates the complexities with which signal engineers are now faced.
A number of previous initiatives have come to fruition, others are still being taken forward:
- ‘Plug and play’ cabling.
This is a dreadful term, since it is anything but ‘play’, but it is now routinely applied to most signalling projects, mainly for the connection between trackside location and local devices such as signal heads and point machines. The idea allows much greater testing to be carried out in the factory, thus saving time. Lessons learned have shown, however, that the original intent to apply the plugs to long lineside cabling is inefficient, due mainly to the range of lengths that would need to be stocked for spares.
- Product acceptance.
The often arduous process of getting new products accepted has been tackled head on by SIG. Equipment worthy of note, and now approved, includes the ElectroLogix interlocking developed by Atkins, now in use on the Shepperton Branch and in progress for the Norwich-Yarmouth-Lowestoft resignalling project; also the updated Ansaldo (now Hitachi) interlocking employed on the Ferriby to Gilberdyke project.
- Aluminium cabling for power. The Class II lineside power supply for signalling systems now uses two-core instead of three-core cabling. This, in itself, saves a third of cable costs, but the adoption of aluminium instead of copper cores gives further reductions in price. SIG has been instrumental in achieving product acceptance for the many components and cables required.
- Regional team assistance.
Getting track circuit re-set procedures in Manchester and a new design of theatre style route indicators for the recent resignalling at Liverpool Lime Street are examples where acceptance assistance has been given to regional teams.
- Level crossing PLCs.
Some level crossings are now equipped with proprietary PLCs (Programmable Logic Controllers), thus reducing project cost. However, more work is needed to get a consistent set of requirements and to understand properly what is available in the commercial market. Being a tiny user in the vast quantities that are manufactured makes any special adaptations difficult.
With the overall aim of reducing SEU costs by almost half, various innovations are underway, not always directly associated with signalling hardware and systems.
- Tail Lamp Camera
This is a misnomer as the device is at the front of the train but hung on the tail lamp bracket. It incorporates a standard high-definition camera, is battery powered lasting up to six hours and is controlled using custom software developed for SIG. Pictures are taken at 25-50 frames per second with a GPS positioning reference incorporated. Greater positioning accuracy will increase the usefulness of the system for detailed design, and more work is planned on this element.
Originally envisaged for signalling needs, it is now extensively used for many asset-inspection purposes, for example saving around 5,000 site visits for the measurement of bridge parapet heights in the East Midlands.
Agreement has been reached with most TOCs for the camera to be put on any train, but with every journey being accompanied by an engineer who fits the appropriate camera for the purpose intended. This is normally a single forward-facing camera, but variants can include extra cameras viewing down to the track or out to the side. It is normal for images to be taken in both directions if double or quadruple track.
One of the ongoing challenges is transferring the images over existing network infrastructure owing to the file sizes involved.
- Positioned Video Pixels
For signal sighting purposes, obtaining an accurate picture of the area where the signal is needed can be a fraught process. The old methodology of going to site with replica signal boards is long gone, but use of video and laser technology requires more development.
The latest result is a 4K ultra-high-definition video imagery and laser pointcloud system, three of which are now available, two mounted on maintenance vehicles, the other fitted as required to a Class 37 locomotive. The latter has permanent fixtures including power supply, cable looms and brackets to which a dual laser source can be attached. As part of the overall SIG service, an in-house train planner is also part of the team.
The resultant images enable signal sighting and its associated sign-off by many departments to be achieved off-site as it is capable of very accurate measurements. Laser data enhances the flexibility of video pictures. The signal engineer can position the signal where it is required and then assess this against other existing and proposed structures, such as OLE supports and gantries. Various assets can be inserted so as to visualise how the signalling will fit into the overall scheme.
All information is stored in a data model for the area or layout. The forthcoming Leeds to Manchester trans-Pennine upgrade will be using this modelling system. The images can be used for design, construction and access planning and can be downloaded to portable devices to assist trackside workers.
- Signal-Sighting Form Tool (SSiLT)
It traditionally took significant amounts of time to generate a signal-sighting form and obtain all the necessary signatures. If an electronic form with electronic signatures were to be available, the time taken would be significantly reduced.
Such a system has thus been devised and is now a mandated format with records stored in one place. The system can be updated from other signal sighting methods through SIGs common data format, and a Signal Clearance Calculator interfaces with track geometry data to ensure the end result is not foul of the gauge.
- Headway Analysis Tool
Predicting future traffic flows and calculating the possible headways required to achieve the train service pattern is an interactive process. SIG has developed tools to optimise the process, commencing with the foreseen headway requirements and then inputting the train characteristics, such as length and speed, loading the given signalling system layout design and, finally, calculating whether it achieves the necessary results. If not, then a rework is required until an optimised solution is eventually achieved.
The digital railway and associated radio-based train control will require a new approach to signalling design if the SEU cost reduction is to be achieved. A design automation strategy is thus being devised that will deliver many principles of BIM (building information modelling) through a core data model that is stored, extended and shared through the project life.
A number of key steps are required to achieve this:
- Step 1 – Asset Discovery.
Asset data is collected by various means from surveys and existing records, usually in different data formats and covering different disciplines – track, signalling, overhead electrification, power and suchlike. Workstreams are underway to integrate these accurately in order to obtain a complete record of survey data and to identify the assets from the images automatically. This will yield many benefits in safety, time and cost, but the result has to be 100 per cent accurate in order to eliminate inefficient human activity.
- Step 2 – Scheme Design.
Automation will free up the designer to concentrate on the key issues that introduce risk to the proposals. As signalling, track and electrification design progresses, so the identification of problems, trade-offs, risks and cost can be analysed and changes made more effectively by automating time consuming repetitive aspects.
- Step 3 – Design Review.
Having designed a new scheme based on an underlying model, interactive review can then take place, including simulated trains running through the layout to prove the effectiveness of the signalling. This enables better visualisation of the results and the changes that may be needed to obtain optimum performance.
- Step 4 – Detailed Design.
At this stage, data needs to be shared with the supply chain, who can automate elements including signalling controls, power supplies and construction. Establishing data-exchange criteria will enable structured data to be provided during the bidding process and returned (in updated form) on project completion.
- Step 5 – Construct and Test.
Ensuring that a project is built on a ‘right first time’ basis is crucial, as re-work costs money. The new approach for design tools can be extended to provide greater support during later project stages and, whilst ‘right first time’ is the ultimate aim, when problems do arise, they can be resolved with the best decision support available.
- Step 6 – Whole Life Management.
Once commissioned, the project elements need to be integrated into all existing asset management systems.
It is estimated that the development of the core automated design process will take five years, and SIG is working to deliver this as part of Network Rail’s CP6 R&D provision. Data is at the heart of the process, with core software tools for visualisation and finalisation of scheme design supported by modular extensions for specific tasks. Currently, development is in the first year with the goal of having multiple ‘proofs of concept’ available so that the overall proposal can be demonstrated to stakeholders, including users, management and potential suppliers.
There is much work still to be done to achieve the end game of enabling automation tools built around a scalable core data model. With continuing devolvement of activities down to the new regions, a means of ensuring a universal commitment will be part of the challenge.
A European project that has existed for some time, EULYNX aims to specify and standardise the interfaces between electronic interlockings from different suppliers with the outside components of a signalling scheme, such as points, signal heads, axle counters, track circuits and so on, with the overall objective of facilitating equipment from different suppliers to be incorporated into the same project.
Achieving cross acceptance within 12 infrastructure organisations in Europe (Germany, Netherlands, Belgium, France, Luxembourg, Great Britain, Finland, Norway, Sweden, Slovenia, Switzerland and Italy) was never going to be a fast process, but members of SIG head up the assurance aspects and alignment of data structures. With meetings in a number of different European cities, it has the spin-off benefit of observing what other European railways are doing in the field of innovation.
Getting a signalling scheme plan right at the outset of a project is important and time consuming. Whilst computer aided design (CAD) techniques have been employed for some time, these have limitations in how they analyse the suitability of the plan for the eventual project.
Hitachi Information Control systems Europe (HICSE) implemented SIG’s requirements for a SKETCH tool that not only makes drawing of a scheme plan much easier but also allows many more elements from other disciplines to be included with sufficient intelligence to alert designers that the plan may have deficiencies. This is acknowledged as a first step toward automating the design production.
SIG will promote the system within Network Rail and the supply chain, as well as providing second line support and training of the design teams. A further article on how it all functions will be written for Rail Engineer later this year.
In closing, David Shipman was keen to stress that the above are all examples of how innovation in signalling has migrated to a different perspective and is now much more focussed on design challenges for a total railway solution. While previous work relating to new hardware or component elements will not be forgotten, it is less likely to produce the savings required to make signalling more cost efficient than the initiatives now being taken forward by the Signalling Innovation Group
Long may these continue.