Rail Industry Focus

Thameslink completes significant signal testing

Martin Chatfield, project director for high capacity infrastructure on Thameslink, gives RTM an update on the project's signalling works and testing.

Last summer, Govia Thameslink Railway (GTR) successfully completed a test run of the new Class 700 Desiro City train through central London using ETCS Level 2 in-cab signalling. 

At the time, this was hailed as major milestone in the journey towards running 24 trains per hour (tph) through the ‘core’ from December 2018. But, as Network Rail told RTM, for their engineers, this achievement marked the starting point of a major 12-month programme of testing. The success of the Class 700 run was built on the previous testing at ENIF and Network Rail’s Class 313 ERTMS test train in the core. 

When we spoke to Martin Chatfield, project director for high capacity infrastructure on Thameslink, it was shortly after the team completed its last shift of testing on 30 July. 

Prior to this, the Thameslink team had undertaken approximately 170 nights of testing, including several weekends, in the core. 

“Effectively, we were testing how the system behaved and whether the ETCS was doing what it should or is expected to do. This was particularly focused on reliability for when we commission it,” he said. “It is one thing to say it is up and running and working, but obviously we want to make sure that when we do introduce it, and switch it on for real, that it is reliable and as many of the bugs have been removed as possible. 

“Whilst that is the ‘real’ testing, there has also been an awful lot of evidence gathering between the Siemens train team, which we integrate with, and our own verification and validation team.” 

ATO stopping accuracy 

In-cab signalling is required to allow trains to run automatically, under driver supervision, between St. Pancras and Blackfriars. However, in order to meet the 24tph specification through the core, it is also necessary to deploy Automatic Train Operation (ATO). 

Much of the testing work has been undertaken in terms of ATO, with the focus being on the stopping accuracy, noted Chatfield: “We just want to make sure the train stops exactly where we believe it should do, and we have been working with GTR to make sure they are on board with that as well.

“We’ve also focused on the ride quality, as we don’t want the train accelerating too fast or decelerating too quickly. So there have been a few tweaks that the Siemens team have done with the ATO over this period.” 

ATO will provide a theoretical capacity of 30tph through the core, explained Chatfield, which creates the capacity headroom to run 24tph with manageable recovery margins. 

“Conventional signalling offers 20tph and ETCS offers 21tph,” he said. “ATO will then provide 24tph. But in perturbation, we would expect to be able to run up to 30tph to recover the timetable as quickly as possible. 

“ATO is showing through the testing that we are achieving consistent journey times whilst under ATO, which reinforces the modelling that we have been doing.” 

Network Rail’s testing has, so far, shown that, should a train not able to run in ETCS or ATO, it can actually deliver 24tph with two trains not running in ETCS and ATO. If there was an on-board system fault with one train, and that ran conventionally, the team is still confident that if the rest of the system was working, and the other trains were still in ATO, 24tph could still be delivered. 

ETCS-ready core and Cambrian learning 

Back in what now seems the dim and distant past, as part of the Thameslink Programme Key Output 1, the core was re-signalled with four-aspect signalling. “We commissioned that work in 2011 to take us from running 15tph under the old signalling system to 20tph, but we also built in the ETCS capability that we were going to need,” added Chatfield. 

“Because the access is so precious in the core, we knew we couldn’t go back in ripping up the signalling and adding new block sections – a fundamental pre-requisite of ERTMS Level 2. So, when we designed that scheme, right at the back end of it, we added in some short block sections. 

“Effectively, we used the access to prepare for ETCS in the future, making it ETCS-ready. While we introduced the Key Output 1, we also replaced the old interlockings at Victoria and West Hampstead with new Westlock CBIs.” 

Reflecting on what has made the project a success so far, Chatfield stated that the lessons learned from the ERTMS Early Deployment Scheme on the Cambrian Line in Wales, which was the pilot project for Level 2 deployment to other parts of the UK network, have been critical. 

The Thameslink team was heavily involved in the Cambrian lessons learned, and RTM was told a key principle of the work in the capital has been embedding them. 

“We came out with five key lessons. Even now, especially as we introduce Traffic Management, we still refer to them,” said Chatfield. “For example, developing the operational principles right at the start of the project; it is no good trying to change the operational principles halfway through when you have designed a system. That is something we adopted straight away and used the principles to help design what we were doing.” 

It was also recommended to test as much of the system away from the operational railway as possible, and Thameslink has continued to use its Integration Laboratory for some of the testing. 

Scheduling in enough time to refine the software was also a key lesson, added Chatfield: “Cambrian talked about scheduling four to five software rebuilds so we planned about seven, and that allowed us to work with Siemens Trackside to have some float in the system.” 

Also, starting the safety case at the beginning when designing the system, so it evolves with the project, has been a fundamental approach for the Thameslink team. 

And, rather than trying to introduce everything at once in a big bang approach, incremental introduction has underpinned the project. “It is the hearts and minds,” RTM was told. “If you spend time stepping up the system you can bring the people along with you. Quite often it is the people that either prevent you using the system, or how you want to, because they don’t believe in it or they are dubious.” 

ORR submission, training and introduction 

Fast-forward to this summer, the Thameslink team is now in the process of submitting a technical file to the safety review panel, which will then be progressed to the ORR for final approval. 

“The six-month period between July and December is allowing for the technical file to be submitted to the safety review panel; once this is approved by the panel it is then progressed on to the ORR,” said Chatfield. “We have allowed for around three months for the regulator to review that file. We expect them to approve that and then it can go into service on 2 January.” 

One of the other things the team has started is making sure the route teams are trained and comfortable with the changes. 

“In the last month, we commenced our signaller training, which incorporates ETCS,” he said. “Effectively, that will run for two or three periods while we get all the signalmen on duty and various controllers up to speed with what the system does, how it behaves and how they then signal trains. 

“We built a specific simulator at Three Bridges Rail Operating Centre, and it is in the process of being upgraded to ETCS and Traffic Management. 

“That is a dedicated room for ETCS, ATO and, eventually, Traffic Management simulation training. During the training, we provide them with, initially, a simulator and then we get a very specific geographical simulator which, effectively, mimics the core area – and that is what they are currently using to deliver their training.” 

By the end of the year, approximately 16 signallers, 10 SSMs, and five local managers will have undergone training.  

And with regards to incremental introduction, a fundamental lesson from Cambrian learning, there will be a capacity change through the core to run 20tph from the May 2018 timetable before the uplift to 24tph from December. 

“Our infrastructure readiness needs to be in place before that timetable change,” said Chatfield, adding that because of the one team approach that Thameslink has adopted with its supply chain partners he is confident this can be achieved. 

“When you want to implement the first high-denisty ETCS system in the world, there is no room for people to be precious about the badge they wear – it is about the end result,” he concluded. “This has delivered a high-performing and committed team, one which shares the risks and challenges but is working together towards a collective goal.”

For more information

W: www.thameslinkprogramme.co.uk