The European Rail Traffic Management System, currently being trialled on the Cambrian line in Wales, is due to be rolled out onto the Great Western next and eventually onto the whole Intercity network. Katie Silvester finds out how it’s going
In October 2010, the very first passenger service to be controlled by the European Rail Traffic Management System ran on Arriva Trains Wales’ Cambrian line.
The advanced signalling system – which, as the name suggests, is designed to be compatible across the European continent and beyond – will bring about the biggest revolution in signalling since the railways began. Instead of lineside signals, the signals are inside the driver’s cab and could eventually increase capacity at bottlenecks by allowing a greater frequency of trains than could safely be accommodated using conventional signalling.
The Cambrian line is being used as a pilot scheme. The route was chosen because its self-contained layout made it ideal for experimentation – and it needed resignalling as the old system was becoming life-expired. ERTMS has replaced the radio electronic token block system. ‘There’s now one of the most advanced signalling systems in the world operating on a fairly rural route,’ says Jim Morgan, Network Rail’s sponsor for the ETRMS programme.
But, he adds, even when ERTMS has been fitted to most major lines over the next couple of decades, it won’t find its way onto all rural routes. ‘It’s not worth resignalling manually signalled routes, where you’ve got an awful lot of not very well-utilised infrastructure out there. You wouldn’t ever want to fit a pacer with ERTMS, I don’t think.’
But back to the Cambrian line. ‘It’s going very well – we’re pleased with the way the rolling stock, the drivers and the signallers have taken to it.’
One unforeseen problem on the coastal route, however, involved the sun refl ecting off the sea and in through the driver’s window, making it diffi cult to read the screen. ‘We thought we’d tested it with bright lights shining from all sorts of angles before we took it to the Cambrian,’ admits Morgan. The problem was soon ironed out using screens and shading on some of the side windows, plus better contrast on the screens themselves.
Peter Leppard, operations director at ATW, is pleased with the way the trial has been progressing: ‘It’s been a tremendous learning experience for us. It’s beginning to settle down and I think we can see now that it’s going to be absolutely fi ne. In safety terms it’s been completely reliable; there’s never been any doubt about it. It’s a completely safe signalling system.
‘As with any new system, there have been teething problems. The installation of modern electronic equipment in the shape of ERTMS kit onto quite old trains – the Class 158 dates back to 1990, so before the time of most computers – has caused one or two odd faults that have taken some trouble to fi nd. And the radio block centre, the modern name for a signal box, has had one or two features in the design that caused some glitches, because it’s basically designed for a double track railway and the Cambrian is a single track.’
Initially, the ETRMS trials just ran between Pwllheli and Harlech at the north end of the line. The full route was commissioned in March 2011. After some initial trepidation, the drivers are now happy with the in-cab system, says Leppard. ‘If you went down there now and spoke to them, they’d all tell you that it’s bread and butter stuff and they’re completely used to it.’
ERTMS is not one single system; it has three levels that offer increasing sophistication. Level 1 focuses mainly on safety – it is the European standard version of the UK’s automatic train protection system, which stops trains passing signals at danger. At Level 1, information about speed limits is passed to a screen, or driver machine interface (DMI), in the driver’s cab via balises on the track, but conventional signals are still used. Axle counters or track circuits monitor a train’s position.
Level 2, which is being used on the Cambrian trial, sees signals replaced by a more sophisticated cab display, but axle counters and track circuits are still needed to provide information on a train’s location.
Level 3 is still being developed, but it will eventually see the introduction of moving block signalling, where radio signals would be able to continuously monitor a train’s position. This will potentially allow for trains to run more closely together than they can using traditional signal blocks.
‘If you look at the East Coast Main Line, ETRMS is not going to give you more capacity because it’s constrained by its junctions,’ explains Morgan. ‘But if you look at these remoter lines where you’ve got 20 minute headways, ETRMS could give you a lot more trains – lines like the Highland Line, Aberdeen to Inverness, Aberdeen to Dundee. You can add an awful lot more block sections. So there’s potential for reducing cost for upgrading signalling and improving capacity.’
Cost reductions come into play because belises are cheaper than signals. Unsurprisingly, the DfT wants Network Rail to work with the rest of the rail industry to find the cheapest way to fit ERTMS. Industry-wide standards mean that all the major signalling suppliers have been developing their own equipment, which should all be compatible, offering ‘mix and match’ options when future routes are procured. At Levels 2 and 3, the main cost is in fitting out the trains.
‘If you can make the cab fitment process simple and cheap, you could save a lot money,’ says Morgan.
How big a job is it to fit the kit to a train?
‘It depends on the train! I think it’s fair to say that the wiring in UK trains differs quite a lot. If you look at a new train, that’s fairly straightforward. If you look at an old BR-built train, the wiring can differ an awful lot. The ones on Cambrian involve accommodating a unit the size of small wardrobes and they are a problem, because they take up luggage space. But manufacturers are now getting the size down.
‘Your first of class design might cost you a million quid, because you’ve got to know how to do it and get all the safety improvements in place. Then the cost comes down significantly depending on how many trains you want to do. So it makes sense to do the largest fleets early on.’
From Network Rail’s point of view, signalling centres will have roughly the same staffing needs as they do now – but the job of a signaller will become simpler. An emergency speed restriction, for example, just has to be fed into a computer and within 10 seconds all trains in the affected area will have that information and will have to obey the speed limit.
‘You don’t have to go and put boards out, which can take ages,’ Morgan explains. ‘You don’t have to caution trains until you’ve done that. So emergency, or normal, speed restrictions are much easier to apply.’
The first mainline to use ERTMS will be the Great Western, which is due for a full overlay system to be operational by 2018, as the automatic train protection system in the HSTs will be becoming life-expired. ‘The existing lights on sticks will be there and there will be an overlay of ERTMS. So fitted trains will have the DMI, which will tell the driver what to do. And let’s just hope the signals say the same thing!’
When the Intercity Express fleet – which is set to replace HSTs – goes into production, ERTMS will be in-built from the outset. The same goes for the new Thameslink rolling stock, expected to be built by Siemens. In the meantime, another text track will be equipped on a five-mile section of the Hertford Loop on the East Coast Main Line. Test trains will run during quiet parts of the day, which will allow the new Thameslink and IEP trains to be tested before they go into passenger use. This is due to begin in 2013, but Network Rail is hoping to have it ready from the end of next year.
The DfT-chaired ERTMS Strategy Group, with representatives from organisations including Atoc, the Roscos, RSSB and ORR, is working on a strategy for fitting ERTMS nationally. The current schedule will see the Great Western completed by 2018, though the signals will not be removed until 2025. East Coast is due to be re-signalled with ERTMS by 2025 and the Midland Main Line by 2023.