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Analysis: The digital revolution and the switch to in-cab signalling

ETCS in-cab signalling

Since the first semaphore signals graced the railway in 1841, drivers have peered from their cabs at semaphore arms and coloured lights, and controlled their trains according to the messages they conveyed.

The trains themselves neither knew nor cared what the signals said.

But later came warning systems in cabs that alerted drivers to cautionary signals, and which would apply the brakes if the driver failed to acknowledge their warning.

These systems have become more advanced, to deliver Automatic Train Protection (ATP) or at the very least Train Protection and Warning Systems (TPWS) that prevent trains passing red signals.

Safety was the driving force behind these improvements. Indeed, it was safety that drove the introduction of signals, and the interlocking behind them, to prevent two trains trying to occupy the same section of line at the same time.

Spurred on by the fatal accident at Clapham Junction in 1988, British Rail installed ATP on two lines on a trial basis - the Great Western from Paddington and the Chiltern from Marylebone.

Both proved too expensive to roll out more widely, so TPWS came along instead as a more cost-effective answer to the problem of Signals Passed at Danger (SPADs).

For some time now, Network Rail has realised that signalling itself is becoming ever more expensive and is effectively unaffordable.

It has been pursuing a shift to cab signalling, which can dispense with those lineside lights on sticks and all their associated cabling.

The information they convey can now sit on a screen in the driver’s cab, fed via radio links and an on-board computer. NR might not have its signals and their cables, but instead the train must have extra kit on board.

This is ETCS, which stands for European Train Control System. It’s beginning to make its presence felt on the southern end of the East Coast Main Line as part of NR’s East Coast Digital Programme (ECDP), although the track owner introduced it to the Cambrian Line as far back in 2011 as a pilot scheme.

But the Cambrian is a simple single-track line, albeit long and with passing loops.

The ECML, on the other hand, is a complex, multi-track mixed-traffic railway hosting passenger and freight services from many different operators.

It’s not surprising therefore that the NR manager responsible for the delivery of ECDP, Ed Akers, sees it as an integration challenge rather than a technical one, although there’s still plenty of tech to sort along the way.

Akers also had a pilot scheme on the Northern City Line (NCL) between Finsbury Park and Moorgate, on which only Govia Thameslink Railway runs with a fleet of 25 Class 717 electric multiple units built by Siemens in 2017-18

From his office in York, Akers tells RAIL: “So you take the NCL and say ‘can we do that on an inter-city, high-speed, multi-use railway?’ with something close to 25 railway undertakings and 30 partners overall.”

He adds: “We talk about NCL as the pilot pathfinder and ECDP as the pioneer.”

He suggests that if ETCS can be delivered in ECDP, then it can be delivered anywhere, and that NR can say for signalling: “This is now how we do renewals.”

Asked why NR chose the East Coast, Akers replies: “There are a number of factors. One is that the route is pretty close to capacity, and is at capacity in a number of areas.

“We know that large chunks of the rolling stock, particularly the passenger rolling stock, have some sort of baseline of ETCS.

So, rather than retrofitment, it’s about configuring the on-board equipment to the specification that we need.

“So you start to build this case. The signalling is life-expired or coming to be life-expired, large parts of the rolling stock is ETCS-ready or close to being ready, and the route is at capacity.

They are the main drivers behind why the East Coast is first.”

This enables NR to start eating into the bow-wave of signalling renewals that is coming over the next 20 years, such as at the northern end of the West Coast Main Line in England, where the big power boxes at Warrington, Preston and Carlisle are over 50 years old.

Akers claims that ETCS signalling renewals are roughly 50% of the cost of conventional renewals.

If nothing else, this is an important reason for NR to be keen to switch.

“There’s just physically less to deliver,” he says. “There are no trackside signals. Yes, you have balises and marker boards, and you still have train detection, but by and large there is simply less to deliver.

“It’s also cheaper because we need less access (around half), and as we go through the journey of testing, proving and integrating everything, in theory we should need less time as we go on.”

Then there’s ETCS maintenance. There will be less kit to maintain on the ground, which makes it cheaper.

“We don’t necessarily need fewer staff, but there is less to maintain on the ground, and we’re putting less people in harm’s way, which is important. There will be a team like flight engineers, maintaining it and faulting it from a ROC rather than a van by the side of the track.”

Moving to ETCS

ECDP started with the Northern City Line, where trains are already being signalled over four miles with ETCS as an overlay on conventional signalling.

This means that the colour light signals remain in place and are operational, but any Class 717 that runs onto the route with a driver trained in ETCS must run in that mode.

Drivers yet to be trained work as usual.

Akers says NR plans to remove the signals next spring (a window of February to May), by which time all the route’s drivers will have been trained on ETCS.

From NCL, Akers contends: “We learned a huge amount. Not just in terms of the partnership and the way we work, but also in terms of fundamental concepts such as user-centricity in the design, having the operators and maintainers sat with the engineers, saying how is this best delivered.”

Tranche 2 is what Akers calls the “operational migration area”. Most people would call it Welwyn to Hitchin, on the ECML proper.

He explains that it is the same concept as on NCL, with an ETCS overlay on top of conventional signalling, to allow drivers to be trained over the next couple of years. It will build up the competence and experience of “each and every East Coast Main Line operator”, according to Akers.

The concept might be the same, but the challenge “becomes bigger and wider”.

“We have a specification of wayside ETCS that we call Baseline 3.6 that hasn’t been employed anywhere yet. We have not one onboard product, but at least five to integrate with that wayside software. We have Hitachi, Siemens, two Alstom products, Thales, and we have the CAF product that will be coming to us at some point.”

That’s one technical challenge. The other comes from having several different classes of vehicle.

However, he knows that the team can retrofit a vehicle - because they’ve done it.

He knows they can integrate a vehicle with its existing systems.

They’ve done it on Class 180s and ‘387s’. He knows they can deliver a wayside infrastructure system.

They’ve done it on the Cambrian, on Thameslink, and on NCL.

“So, all these things are eminently doable. But the challenge comes when you overlay the amount of different onboard systems and operators.

And you overlay the existing industry structure.”

It soon became clear a straightforward infrastructure programme would not work. “You have to do this in a different way. You have to do this with all of those organisations that have to own this, operate it, maintain it, run it, drive it - whatever it is, they have to be our delivery partners and they have to be at that delivery table from the word go. Network Rail is an equal partner in an industry partnership.

“There’s a commercial framework that sits around that. We directly contract with each and every single partner - whether it’s freight, passenger, on-track machine, chartered or heritage - and we directly commercialise that relationship.”

It also helps that major operators such as LNER are under Department for Transport ownership, while GTR was contracted on a model that was designed to introduce Class 700s working with ETCS on the cross-London corridor via Farringdon and Blackfriars.

However, as Akers notes, that still leaves ECML freight and open access operators working to much more commercial imperatives.

LNER and GTR also add some complexity from the complex private finance deals behind their rolling stock.

That has not stopped the programme upgrading software on the trains, Akers tells RAIL, but it has made it more challenging.

Overall, ECDP contains 30 partners, more than 700 vehicles (with 250 of the national freight fleet needing to be fitted for ECDP), and around 3,000 drivers who need to be trained in ETCS Level 2.

Behind this second tranche of ECDP lie the three interlockings that NR renewed last February, with axle counters installed to detect trains and balises, which provide fixed reference points on the track.

Now Akers has the detailed task of checking what’s been installed.

That started in April with a train static in Welwyn station checking the connection between the RBC and the train.

“We also have to rehearse and test what we call SPZs , which is the way we will isolate the areas of railway we want to test on a night, so that we don’t have to close the whole ECML every time.”

From the end of May, when Akers expects to start dynamic testing that runs for three months into August as NR starts to build the safety case for ETCS operations.

Then comes a mid-point proving cycle, when he expects to take 12 weeks to fix whatever bugs the earlier test have found and then install updated software, before a second round of proving starts in November and runs for three to four months.

There is also rolling stock to test, such as Grand Central’s Class 180 diesel multiple units, NR’s Class 43s that power its New Measurement Train, the first of the Class 66s to receive ETCS (66039 is now being tested at Old Dalby, RAIL 1009), and GTR Class 387 EMUs.

These tests also take place with different equipment suppliers. For example, the Class 43s have Thales on-board ETCS, while the ‘387s’ have Alstom kit (having come from Bombardier). This is in addition to the Siemens equipment onboard GTR’s Class 717s.

Initial tests take place at Old Dalby (known as RIDC by NR these days), although ETCS’s steam pioneer (‘A1’ class 60163 Tornado) tests will take place on the Cambrian ETCS route in Wales.

These tests will initially focus on the way the onboard kit works within the train itself, with factors such as braking. Then they move to the way the train works with the kit on the ground.

“It’s not so much saying that we need to test a ‘43’ against the wayside, it’s saying that we need to test the onboard product that Thales has, which has already been proven in the vehicle, with the Siemens kit ,” Akers explains.

And that’s all after laboratory testing at Siemens’ Chippenham factory, where each of the onboard systems is being tested against Siemens’ wayside kit - “so that you can get as many bugs out in that environment, rather than finding it for real when you have a time-constrained access window,” he adds.

That level of trust between different suppliers is one of the remarkable aspects of the partnership, according to Akers.

Another aspect is that the fiercely competitive freight hauliers are all working on a single ETCS design for a Class 66 (allowing for the differences in design between ‘66s’), because they all have them.

Target dates

Akers reveals that his target date is to begin migration to ETCS in June 2025 for the Welwyn-Hitchin section.  “Will that plan hold? I don’t know, but we have a plan, and it targets that June date.”

This leads to a working assumption that NR will begin removing traditional signals from the East Coast Main Line sometime in the second half of 2027.

That’s based on it taking up to 24 months to train drivers. Akers admits that no one knows precisely: “We’ve never done mass freight training, so we think two years.”

Under current NR plans, the first section to lose its signals would be Biggleswade to Fletton (Peterborough), although Akers says it could be the Hertford Loop.

So far, these two schemes are moving forward together, before NR decides on which is first.

Fletton has long been the plan, but Akers is attracted to Hertford’s simplicity (with fewer level crossings, for example). However, he acknowledges that it is also a major freight artery.

This means that NR will continue ETCS installation work (balises and signs) while it tests Welwyn- Hitchin, because the key equipment (the interlocking) is already in place and the critical path to success is ECDP partners being trained and ready.

Which is where Welwyn-Hitchin comes into its own as NR’s ETCS training ground.

With ETCS installed as an overlay, drivers can use trackside or cab signalling according to their competence.

NR doesn’t plan to install overlaid ETCS on other sections - they will move from signals to no signals at the point NR commissions their ETCS.

From the first area losing signals in 2027, NR plans to roll on “towards the end of the decade”, with Akers saying that if ECDP is not finished by 2030 it will be completed in the very early 2030s.

He cautions that there are complex areas such as King’s Cross to complete, as well as Peterborough as NR converts the ECML as far as Stoke Junction (a few miles south of Grantham).

ECDP extends beyond simply converting routes, with Akers also looking at the way to bring traffic management into play and planning tools to help construct timetables.

As resignalling with ETCS grows, and more operators fit their fleets and train their drivers, it becomes simpler for ETCS to become business as usual for NR’s renewals.

An extended version of this article is published in RAIL issue 1010. Subscribe to never miss an issue.

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