Signalling the future
In late January, the Institution of Railway Signal Engineers (IRSE), the Signal and Electrical Engineers’ Technical Society (TechSoc London), and the Institution of Mechanical Engineers (IMechE) Greater London Region organised the ‘Signalling the Future’ conference in London. This was a very impressive event, with speakers and experts from around the world and some very insightful presentations and knowledge sharing.
The presenters shared their expertise covering: strategic needs, project and operational experience, and Communications-Based Train Control (CBTC) vs European Train Control Systems (ETCS) technology. CBTC is found in metro light railway and urban mass-transit systems, while ETCS is used for heavy railway systems. ETCS was developed to support interoperability of mainline railways, while CBTC systems are for automated operations on urban railways, and where interoperability is not required.
Andy Lord, commissioner at Transport for London (TfL) gave the opening address. Andy reports to the TfL Board and Mayor of London, with responsibility for delivering The Mayor’s Transport Strategy and the TfL strategy. He is also responsible for all of TfL’s operations across rail, strategic roads, river, bus, and cable car, transporting over 11 million passengers a day. He said the only engineering discipline missing is nuclear, but watch this space!
With a background in mechanical engineering, Andy worked for 26 years in the aviation industry before joining TfL and he said he very much respected signalling engineers and all they do. However, he said procuring metro railway signalling was so much more complex than buying the collision avoidance avionics system on an aircraft, for example. He said that rail industry clients from across the world must agree common requirements and use ‘off the shelf’ technology. Suppliers must also challenge clients and not say ‘yes’ to every bespoke requirement.
Session 1: where are we today?
James Dzimba, chief control command and signalling engineer at Network Rail presented ‘Semaphores to DMIs, ETCS in Great Britain – Do we have a choice’. He explained the history of train protection systems on the GB main line network over the last 30 years, and that the original vision of the Train Protection Warning System (TPWS) as an interim solution pending migration to ETCS has not yet happened. The success of TPWS has made the business case for ETCS difficult, but today the costs of conventional signalling renewals are unaffordable. So, future signalling must be affordable ETCS.
The East Coast Digital Programme is working towards ETCS on 100 miles of busy, mixed-traffic railway, with multiple fleets of trains, including freight, heritage, and on-track plant. Framework contracts are in place with four suppliers who are developing solutions for the West Coast Mainline north of Crewe, Trans-Pennine, Brighton Mainline, Midland Mainline, and Great Western. So, things are finally starting to happen. ETCS will also deliver a better train protection system than TPWS. James said that there is no viable alternative to ETCS and that the pace of delivery must improve, and costs be driven down.
Gary Joynes, principal engineering leader, signalling strategy at TfL, began by saying that when he started his career in the mid-1980s, all but one of London Underground lines had the same signalling system, using lineside signals and mechanical tripcocks. Over the last few decades new signalling and trains have transformed much of the network, and the asset base is now more diverse, with three main technologies: Hitachi CBTC, Siemens CBTC, and legacy equipment.
However, the obsolescence of the more ‘modern’ systems is a problem, together with the upgrade of the remaining legacy signalling. Computing and telecoms components can no longer be expected to last for 40 years and TfL is developing business plans to allow technology refresh. Systems need to be designed to reduce whole life costs and a long-term relationship with the suppliers is essential as the systems are so complex and soon become obsolete.
Jonathan Speak, head of engineering delivery with Hitachi UK, gave an excellent presentation from a supplier’s perspective. He said brownfield deployment is always going to be required with rail and signalling, and that there has to be genuine customer/supplier collaboration.
In the future virtualised hardware agnostic architectures may reduce the impact of obsolescence, together with using COTS system from other industries. Suppliers are looking to use a common platform for their ETCS and CBTC solutions. So, there is evidence of a convergence between mainline and metro applications, and more use of open Long Term Evolution (LTE)/Future Railway Mobile Communication System (FRMCS) communication bearers. A number of FRMCS-ready 5G and LTE comms networks are already being deployed outside Europe, including Australia, South Korea, and India.
Products are also staring to appear using the EULYNX open interfaces between signalling system components, and Jonathan suggested that these may find deployment in metro and mainline signalling applications.
Session 2: project experiences part 1
Gerrard Sheffran, the European Rail Traffic Management System (ERTMS) programme director for the Netherlands, said he was a “signalling novice”, but brought a managerial perspective and lessons learned from the deployment of CBTC and ETCS on the Amsterdam Metro and Dutch railways.
The learning points included that interface management is not enough to achieve integration and there was over-confidence in the added value of requirements management. He quoted the Prussian general Graf von Moltke who said, “No plan survives the first encounter with the enemy”, as the underestimation of the impact of digitalisation overlooked the need for collaboration and reputation management. He added that a focus on strict scope control endangers the delivery of added value.
The current phase of the Dutch ERTMS programme runs to 2031, involving the upgrade of 1300 trains and 700km of route to ETCS Level 2. The programme is divided into tranches of work using different approaches.
Steve Allday, an independent advisor to the National Transport Commission of Australia, presented ‘Achieving interoperability on the Eastern Seaboard of Australia’. He explained that in a country larger than Europe, railways in individual states developed in isolation. This resulted in different track gauges, signalling standards, and competency frameworks.
A recent review of the Inland Rail project, which is building a new route across state borders primarily for freight, recommended that the signalling system should be interoperable with state systems. This has resulted in an ‘Interoperability Action Plan’. Seven key principles have been identified to coordinate the consistent application of ETCS across state, federal, and private sector rail infrastructure managers and operators.
The operational requirements between urban, regional, and remote networks vary, but this needs to be addressed by configuring standard ETCS products from multiple suppliers, rather than by bespoke signalling customisation. A national governance body is to be established, and this may also include closer working with the EULYNX standardisation initiative in Europe.
Continuing with the project theme, Navneet Kaushik, director systems and operations for National Capital Region Transport Corporation in India, described the application of ETCS to a new regional rail network around Delhi. Population growth has prompted development of a Regional Rapid Transit System of eight routes radiating up to 100km from the city centre. The first three routes will be interoperable and ETCS has been selected as the standard signalling system.
A Level 2 system with virtual blocks subdividing the primary axle counter train detection sections will allow trains to operate at two-minute headways at 180km/hr. Automatic train operation (ATO) will be provided and platform screen doors are integrated using ETCS packet 44 messages between track side and train. LTE/4G has been selected as the radio system, using the 3GPP Release 15 standard which provides the necessary mission critical improvements over public mobile communications services. ETCS will only use 1% of the available capacity, so the same network can be used for video transmission from trains.
Session 3: project experiences part 2
Clive Burrows, group engineering director at First Group UK, reminded everyone that ETCS is not the same as ERTMS and that both ETCS and Traffic Management is needed to ‘signal the future’. TPWS has also addressed many of the train protection risks, but not continuous speed supervision.
He described his experience on the Great Western route in UK, where Network Rail has introduced a Traffic Management System (TMS) to manage train movements through a dynamic train plan linked to automatic route setting. Great Western Railway trains are also equipped with a Driver Advisory System (DAS) to optimise train running for punctuality and energy consumption. These have now been linked with a Junction Scheduler that uses information from TMS to send revised target arrival times to DAS at three critical junctions on the route. This results in a Connected DAS (C-DAS) which smooths the flow of traffic.
Clive also said that a cross-industry robust Data Reporting, Analysis and Corrective Action System (DRACAS) is essential to ensure the reliability of ETCS is maintained and improved, and he suggested that a future ETCS Level 5 could include trains learning their own movement authority.
Ankit Dabral, head of business development for Stadler Rail presented ‘Innovation for Rail Signalling and COTS approach’. He outlined Stadler’s entry into the signalling market, initially as a train supplier providing an in-house supply for ETCS on-board equipment and developing through acquiring smaller companies with interlocking and lineside systems. Its strategy includes the use of commercial off the shelf (COTS) hardware, using multiple suppliers to support a robust obsolescence management strategy.
Stadler has developed a cost effective CBTC solution with minimal wayside for light rail and branch line applications as well as its traditional application on urban metros. Recent innovations include camera/lidar/radar sensors for positioning and object detection collision avoidance.
Hugh Rochford, modernisation strategy manager for Paris area, SNCF, described the ‘Modernisation and Roll out strategy in France’ and a prototype project applying the selected technologies on an international high density mainline in the south of France. This envisages using standardised elements and EULYNX interfaces. A standardised interlocking platform, ARGOS, has been developed and this will be deployed with ETCS Level 2 and FRMCS to a common baseline for existing and new lines, managed from less centralised traffic control centres. ATO at Grade of Automation (GoA) 2 is also envisaged on high-speed lines. A national implementation plan has been developed for 5,700km of ETCS-equipped track by 2040.
Daniel Woodland, professional head of signalling (North America) for TÜV Rheinland UK, presented ‘Standards for CBTC and ERTMS’. He began with the basic signalling functions – Lock, Block, Interlock, Authority, Supervise, Unlock – and explained how these apply equally to Metro and Mainline railways, though different characteristics and levels of risk have led to historically diverse solutions.
He provided an excellent explanation of CBTC and ETCS. CBTC standards, principally IEEE 1474 and IEC 62290, are functional specifications defining expected end outcomes and features. There is no mandatory legal requirement for compliance, and railways and suppliers have wide-ranging freedom to specify and deliver solutions. ETCS however is specified within a European legal framework that mandates requirements for interoperability at the ‘air-gap’ between track and train, and requires detailed technical specifications defining the system architecture, interfaces, communication protocols, and reactions.
Session 4: operational experience
The first speaker of the final session was David Sherrin, TfL Elizabeth service reliability manager. He presented ‘Our journey so far, ETCS and CBTC in Passenger Service’. David started by covering the unique features of the Elizabeth Line which crosses London with its own dedicated tunnels in the city centre and runs on Network Rail tracks to the east and west. The line has been an outstanding success and on its busiest days now carries 800,000 passengers daily.
Elizabeth line trains work with three signalling systems, a Siemens CBTC system in the central metro section, AWS/TPWS, and ETCS. The on-board solution is integrated with a common IP backbone so that a single driver machine interface and data logger is shared by the systems. Between Shenfield and Reading, a train will encounter four transitions between signalling systems.
It generally takes two years for a new system of this complexity to achieve an adequate level of reliability. This was the initial entry into service experience with ETCS from 2020-2022 and with CBTC from 2022-2024, and only recently has over 90% on-time performance been achieved consistently. The Wi-Fi solution used on the central section requires a large number of access points which can be difficult to maintain in tunnels, and using unregulated frequencies can be susceptible to third party interference in busy stations on the surface. Both ETCS and CBTC experienced major one-off system-wide failures in the initial period of operation and David said it is essential that complex projects prepare for similar things.
George Jackson (GTR), John Crossland (Network Rail), and Daniel Hill (Siemens) presented ‘Northern City Line ETCS – Lessons Learned’. This is the first deployment within the East Coast Digital Programme and covers the short section of railway from Moorgate in the City of London to Finsbury Park on the main line. This is operated by a dedicated fleet of trains that are already ETCS fitted, so it was an ideal first step in the overall programme.
The line was resignalled with lineside signals in 2022 and an ETCS Level 2 overlay added in 2023. All trains are now running ETCS and the lineside signals will be removed in May 2025. Dedicated teams were established for ETCS data analysis and fault finding, and the lessons are being shared industry wide, as the programme works towards the next major milestone of ETCS Level 2 overlay running on the main line between Welwyn and Hitchin in December 2025.
The final presentation was ‘Deployment of ETCS in Belgium, Key challenges and solutions’ by Bavo Lens, ETCS projects design and test team leader with Infrabel. After serious train accidents, Belgium took a decision on the national roll-out of ETCS and, in 2010, railway undertakings were given 15 years notice to fit their rolling stock by 2025.
Since 2018, Infrabel has been working on a masterplan for deployment of ETCS on the tracks, and by 2024 79% of the network had been fitted with a mix of ETCS Level 2, Level1, and Level 1LS (Limited Supervision). The Level 1 applications are deployed on existing interlockings using Infrabel’s in-house design and installation resources, while Level 2 requires supplier involvement.
Common themes
Despite the wide range of countries and railways represented, common themes emerged. Such as safety is the number one priority, the need for standardisation, simplification, proactive obsolescence management, and less customisation, as well as efficiencies and economies of scale to reduce costs. The event was well received by the international audience, who all gained a valuable learning and networking experience, and understanding of how global railways are tackling the challenges of modern-day signalling.
The take aways included that standardisation and simplicity are key to achieving the levels of interoperability needed to improve the efficiency and cost effectiveness of modern signalling; the provision of large scale ETCS/CBTC systems requires a greater level of cooperation between organisations; and that innovation and an ALARP approach is essential.
Signalling needs to make the most of commercially available communications technology and must also use off the shelf hardware and technology. The industry cannot afford to provide bespoke solutions to address every remote risk. Operational practice must also change to accommodate the signalling technology and not the other way around.
Many who attended said they greatly appreciated Jane Power, president of the IRSE, and the rest of the team for organising such a great event, which brought together knowledge from countries including the UK, Netherlands, Australia, India, Switzerland, France, USA, and Belgium. A special thanks was also made to the IRSE sponsors – Hitachi Rail and Stadler Rail (Gold), and RSSB and CPC Project Services (Bronze), who made the event possible.
Image credit: Network Rail
