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Upgrading the continental connection

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Another ERTMS announcement has recently emerged, this time concerning the London to Paris and Brussels high-speed routes through the Channel Tunnel. At a meeting in Paris on 19 July, an agreement signed by four parties – UK HS1, Eurotunnel Getlink, SNCF Reseau and Infrabel – stated that they would work together to introduce ERTMS (European Rail Traffic Management System) on the routes concerned.

This came as a bit of a surprise and there was very little detail as to what was actually being planned, so Rail Engineer went to meet HS1 and learn some more.

The cross-border cooperation on ERTMS was signed by (L-R) SNCF-Reseau president Patrick Jeantet, HS1 CEO Dyan Crowther, Infrabel CEO Luc Lallemand and Getlink chief corporate officer Michael Boudousssier.
The cross-border cooperation on ERTMS was signed by (L-R) SNCF-Reseau president Patrick Jeantet, HS1 CEO Dyan Crowther, Infrabel CEO Luc Lallemand and Getlink chief corporate officer Michael Boudousssier.


It is now some 24 years since the Channel Tunnel opened and Eurostar services began from London’s new international terminal at Waterloo station. The French, in their typical enthusiasm, had opened their high-speed line from Paris to Calais in readiness for this but the British and the Belgians were reliant on their existing rail networks to connect in to the cross-channel services. In time, both Belgium (in late 1997) and the UK (partly in 2001 and fully in 2007 to St Pancras) constructed high-speed lines using the TVM 430 train control system designed by the French. So far as railway technology is concerned, both the Belgian and British high-speed lines are essentially SNCF extensions.

Not all the TVM 430 equipment is from the same vintage; the cab displays are identical but the interlockings in France and in the Tunnel are relay-based whereas those on HS1 are solid-state. The system uses track circuits for train detection and position information from which the ‘distance to go’ cab commands are derived. With the oldest equipment now well over halfway through its expected lifespan, planning for renewal makes sense.

The main driver is, however, not renewal but the need to expand the routes that the London/Paris/Brussels configuration can offer. Already, the extension of Eurostar services to Amsterdam has begun, enabled by a treaty with the Dutch rail authorities, but a new vision exists to achieve greater utilisation of the infrastructure. Bordeaux is very much a target, using the SNCF and LISEA-owned TGV South West line via Tours, but there are also plans to expand into Germany and beyond. Introducing ERTMS/ETCS (European Train Control System) for train control will improve international interoperability further and make cross border crossings as seamless as possible.

The cab of a Siemens-built Eurostar e320 train. The control desk is fitted with displays for both TVM 430 and ETCS. Photo: Eurostar.
The cab of a Siemens-built Eurostar e320 train. The control desk is fitted with displays for both TVM 430 and ETCS. Photo: Eurostar.

Technical challenges

ETCS has reached maturity, at least as far as Level 2 is concerned. With the software stabilised at version 3.0.0 and products from many suppliers all being capable of working with each other, it would be easy to presume that to convert the aforementioned high-speed lines is a simple project.

In some respects, this is true, but changing from one train control system to another brings its own set of challenges. Nothing can be done overnight, so a plan to have both old and new systems in operation at the same time needs to be produced. This means either having to duplicate the infrastructure or dual-fit the trains.

On a much smaller scale, London Underground faced this dilemma when upgrading the Victoria line and solved it by having the new ground based signalling overlaid onto the old. Doing this for the London-Paris/Brussels lines might result in something similar, but it is a much larger project and will mean making the change for the various sections of route at different times.

Indeed, because of the different ages of the TVM 430 equipment, the oldest in France and the Channel Tunnel will be the first, with that in Belgium coming later and HS1 being the last to be replaced. This will ensure that the installed equipment base has a reasonably long working life.

It must be remembered that ETCS is a radio-based system whereas TVM 430 uses track circuits, so the changeover will be a new method of working. For the Channel Tunnel, getting the radio signals in place should present no difficulties as many long tunnels in Europe and beyond are equipped with radiating cable – see the Rail Engineer article in issue 166 (August 2018) on ETCS operation in the Gotthard Base tunnel.

The Paris to Lille section has the most urgent need as this currently carries the most traffic – Eurostar, Thalys and other local services – with a need to increase the current capacity of 15 trains per hour.

In contrast, the Channel Tunnel is presumed to be the most complex as the new system must be capable of bidirectional working in the two tunnels plus changing from one track to the other at the two crossover points.

The provision of ETCS in-cab equipment will be a major consideration. The new Eurostar Class 374 trains from Siemens (the e320 class) already have it, since it is needed for the Brussels to Amsterdam high-speed line. The older Alstom-built Class 373 trains will need to be equipped, as will the Thalys trains that operate the Paris to Brussels service.

In the UK, the Class 395 Javelin trains of Southeastern will similarly need to be fitted, as will the locomotives that work the growing number of freight trains operating over the route and, of course, the shuttle trains which carry cars, buses and lorries through the tunnel. Yellow plant and other engineering trains must also be considered.

The radio element of ERTMS is another factor as, whilst all the trains are presumed to have GSM-R, many of them will only have it in its basic form for speech communication and limited data. Fitting a data radio to the trains for the communication link to the ETCS commands will be necessary.

GSM-R, as has been reported in previous articles, uses an obsolete technology based on the 2G mobile phone standard, and replacing it with either a 4G or 5G network is likely to take place anyway during the timescale of the high-speed lines upgrade. HS1 is well aware of this and will be watching developments closely.

Another parallel development could well be the emergence of ERTMS Level 3, especially the Hybrid version which would retain existing train detection equipment (track circuits or axle counters) in the short term but allow Level 3-fitted trains to operate with the potential capacity advantages of moving block that this would yield. Again, HS1 is keeping a close eye on progress.

Gare St Jean in Bordeaux. Photo: iStock.
Gare St Jean in Bordeaux. Photo: iStock.

Traffic management

The pinch point of these high-speed lines is the Channel Tunnel, where Eurostar trains have to arrive at the portals within three minutes of the timetable to ensure a smooth transition. To achieve this in all circumstances requires a traffic management capability of being able to ‘look back’ at how the train service is running on the other side of the channel, and this facility is currently very limited.

For this reason, a fully fledged traffic management system is part of the upgrade plan so as to have the ability to look at the overall performance of all train services across a much wider area in order to prioritise Eurostar services should any out-of-course running occur.

Commercial considerations

A project of this magnitude must have a robust business case. Much of this will be based on demand forecasting in the pursuance of a wider European high-speed network. Having different technologies currently makes cross-border operation complicated and expensive and thus fitting both infrastructure and trains with a common system will lead to economies.

Whilst HS1 and Eurotunnel are separate entities (and French high-speed operation is going that way – LISEA is a private company now operating the Tour – Bordeaux line extension). These lines have to interface with national networks – Network Rail, SNCF Réseau and Infrabel – to offer an end-to-end service. Interfaces, both technical and commercial, can lead to acrimony if not properly managed and thus it is seen as vital that commitment from the chief executives of these organisations is obtained to ensure complete co-operation.

The cross-channel shuttle trains will also need converting to ETCS control.
The cross-channel shuttle trains will also need converting to ETCS control.

What next?

Clearly this project is long term. Six work streams have been identified as being needed to get the project off the ground:

  • Interface Strategy – including co-operation on project management;
  • Engineering Development – for a common design for the ETCS solution;
  • Procurement Strategy – to ensure an agreed approach and tendering requirements;
  • International Demand Forecast – including business opportunities;
  • Funding Strategy – to have an opportunity for European joint financing;
  • Communications Strategy – for the what, where and when questions in anticipation of stakeholder involvement.

A provisional development programme is expected to be in place by the end of 2018. Service introduction in France and the Tunnel is anticipated by 2025, in Belgium by 2030 and on HS1 by 2032. A rough estimate for the HS1 section is £70 million, including the necessary research and development. This excludes the cost of any train fitting.

The benefits are potentially great and could revolutionise pan-European train travel. The technical aspects will be the most interesting to follow as these have to go hand-in-hand with engineering developments in the general rail arena. Mutual co-operation with HS2 is anticipated, so perhaps we will see services from the north of London direct to the continent after all.

Now there’s a thought.

Thanks to Edmund Butcher and Richard Thorp from HS1 for their assistance with this article.

Read more: High Speed One renewals programme


Clive Kessell
Clive Kessellhttp://therailengineer.com
SPECIALIST AREAS Signalling and telecommunications, traffic management, digital railway Clive Kessell joined British Rail as an Engineering Student in 1961 and graduated via a thin sandwich course in Electrical Engineering from City University, London. He has been involved in railway telecommunications and signalling for his whole working life. He made telecommunications his primary expertise and became responsible for the roll out of Cab Secure Radio and the National Radio Network during the 1970s. He became Telecommunications Engineer for the Southern Region in 1979 and for all of BR in 1984. Appointed Director, Engineering of BR Telecommunications in 1990, Clive moved to Racal in 1995 with privatisation and became Director, Engineering Services for Racal Fieldforce in 1999. He left mainstream employment in 2001 but still offers consultancy services to the rail industry through Centuria Comrail Ltd. Clive has also been heavily involved with various railway industry bodies. He was President of the Institution of Railway Signal Engineers (IRSE) in 1999/2000 and Chairman of the Railway Engineers Forum (REF) from 2003 to 2007. He continues as a member of the IRSE International Technical Committee and is also a Liveryman of the Worshipful Company of Information Technologists. A chartered engineer, Clive has presented many technical papers over the past 30 years and his wide experience has allowed him to write on a wide range of topics for Rail Engineer since 2007.


  1. I have given a lot of thought to this myself as the expansion has so much potential. To me apart from Bordeaux, a service from London to Gothenburg via Amsterdam, Copenhagen and Malmo is a strong candidate. The possibilities are endless, even Hamburg, Szczecin (PL) and Gdansk would have advantages. But if HS4air is built (and it really should) then we could see trains from Birmingham to Lille and Paris or Brussels/Amsterdam from the start, stopping at Heathrow, Gatwick and Ashford on the way. It may be less ground covered on long journeys but serves as a regional stopping service for people from Bristol, Cardiff and the South Coast to join a lot more effectively.

  2. ETCS essential requirements in current EU regulation 2016/919 CCS TSI includes technical standards identified as Baseline 3 Release 2 or v3.6.0 being the latest stable version. ETCS Level 3 hybrid can reduce amount of train detection by adding virtual blocks (software) but in terms of hardware is not different than ETCS Level 2. There is a clear benefit in considering ETCS Level 3 hybrid approach.


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