Rail Industry Focus


Availability, maintainability and reliability - SSR re-signalling

Source: Rail Technology Magazine March/April 2013

The new signalling system for London Underground’s sub-surface lines is being tested at the Old Dalby test track in Leicestershire. RTM talks to Bombardier’s project manager Peter Acton.

Testing has now begun on the new signalling system to be installed on London Underground’s sub-surface lines, in a joint project between LU and Bombardier, whose Cityflo 650 system is being installed across 310km of track and 113 stations.

LU and Bombardier are installing the new Cityflo 650 system to run more trains and increase capacity. The contract is worth around £354m. The upgrade also covers equipment installation for 191 S Stock trains, 86 Piccadilly line trains, 49 engineering trains and six heritage trains; one integrated service control centre and back-up facility; seven signalling equipment rooms; and 36 major track layout changes.

Bombardier’s Peter Acton is helping deliver the project, based out of TfL’s Buckingham Palace Road offices. He told us: “We need to get this railway system moving at 32 trains per hour, up from 27 at the moment – that’s the crux of the matter.

“It’s about moving people quicker, having a closer headway. This is not a fixed block; it is a moving block format so you are going to have trains not far from each other. You’re going to be able to see the back of the train in front of you.

“People will be shifting through London much more quickly, efficiently and effectively than today.

“Obviously we’re working very hard on reliability, with new trains and new signalling.

“The beauty about this signalling is that it’s got fewer parts and fewer components.

“We’re delivering it without any closures. If you work in London or travel around London, a closure is nothing but a pain.

“However, we are hoping to take advantage of some of the closures that the track people have in place, if we can jump on the back of one of their closures.

“Engineering hours equals 3.5 hours a night, but if I have a weekend, I can do two weeks work in one weekend.”

No overlay phase

As explained in our interview with LU capital programmes director David Waboso on page 56, a key reason for Bombardier’s Cityflo 650 being chosen was seeing how easily it was installed in Madrid.

But the London installation, due for completion by 2018, will actually be even smoother, Acton told us. “We’ve learnt our lessons from Madrid and from the Victoria line as well [that project, with LU and Invensys Rail, finished recently after nearly nine years of upgrade work on the line, delivering 30tph capacity in the peak.]

“We ‘did the job twice’ on those: we did an overlay phase and then an asset replacement phase.

“We have avoided that here, by designing straight into the ATO asset replacement stage.

“The advantage of installing it is that we do it once, and of course we’re helped here because unlike say on the Victoria line, where we had old trains in initially and then we had new trains coming on board, we’ve got the new trains already there coming in.

“So we’re going straight into the final state, the asset replacement phase.

“Bombardier Transportation’s approach is to provide a new system as an overlay on top of the legacy signalling set; on commissioning, the old legacy system simply becomes redundant.

“It is simple and it’s an almost beautiful situation to be in; there is no interface needed to the old legacy system at all, because we’re missing out that overlay stage.”

Another big advantage is the lack of cabling. Acton said: “Basically the only cabling we’ve got is two leaky feeders and two power cables. That’s less than one-tenth of the infrastructure today. It’s phenomenally less to install, and it means there’s less chance of it getting snagged, damaged or stolen.”

Old Dalby testing

Testing is taking place at the 13.5-mile Old Dalby test tack in Leicestershire, where the S Stock trains were tested and commissioned.

Phase one testing took place just before Christmas 2012. It involved testing norming points at high speed, and a Doppler radar vehicle engineering test to ensure the Doppler speed detector unit was mounted and operating correctly on an S Stock train.

The third test was the wayside radio communication test with a radiax cable and an S Stock vehicle, to test the quality of the RF signal from the radiax cable to the vehicle radio.

The forth test was the EBI Track 2000 axle counter. “This is a very important one,” Acton said. “We wanted to test the axle counter operation in a full rail environment with an S Stock train, so that we could gather evidence to support the cross-acceptance of that product.

“Those four tests in phase one were all conducted successfully prior to Christmas.”

Phase two, going on as RTM went to press, is more complex and all about risk reduction. Acton said: “The scope is tags and reader interface tests, to test the possible interface between the ATC norming point system against the tag radio system, the AIT tag system and the APMS tag system.”

That was to verify that there’s no interference between the tag systems, while the next test was to re-test the Doppler radar in a non-reflective environment (water). “We’re looking at a stiffer bracket; that was a mechanical hardware test that has less vibration. The risk reduction there is to make sure we don’t have a blackout condition and the signal to noise ratio, we don’t want any radio noise going on in that.”

The third phase two test is measuring the strength of the signal down the radiax cable, 316 metres of it. “We want to make sure we can maintain the test signal strength as the train moves along that cable, and ensure the quality of the signal strength of the new cable is maintained: it basically either works or it doesn’t.

“Last but not least is the vehicle and wayside radio communications test with the line-ofsight and antenna with the S Stock vehicle. We want to check hand-off of the communications from the line-of-sight communications system to the radiax communications system and to verify the correct functionality, following architectural changes to on-board radio systems, to improve availability.

“Availability, maintainability and reliability are really high on our agenda here.”

Next steps

In the summer, the next stage begins, step one of which is the S Stock vehicle ATC – VATC hardware acceptance. Step two, in the autumn, is the wayside radio DTS system acceptance.

Old Dalby test track testing and demonstration acceptance – the G0 demonstration – is in April 2014. Acton said: “We’re leading up to some real testing here. Along the road we have something like 115 functionalities to test and in the region of 1,000 requirements.

“For the last two weeks prior to the GO date on 28 April next year, London Underground actually take control of everything for two weeks and do their own tests and make sure what we’ve delivered is in accordance with the contract.

“It’s not a cold handover; they’ll be with us all the way through, from December last year through to April next year.

“London Underground do have embedded staff in our organisation who are learning and training up on the Cityflo infrastructure.”

Daily interaction

Asked how well LU and Bombardier have been working together, Acton explained: “They’re the customer, we’re the supplier, so we do still have that commercial contractual relationship.

“But we sit in the same office, I sit next to the project director for London Underground, and we have that daily interaction and chat about everyday things – so it’s not like we’re only coming together once a week to talk about specific key issues, although of course we do still have those meetings.

“The way we’re sitting together, it’s like we’re in a consistent project review all day everyday.

“There are privacy issues, but I think the positives outweigh the negatives.”

Tell us what you think – have your say below, or email us directly at [email protected]


There are no comments. Why not be the first?

Add your comment


rail technology magazine tv

more videos >

latest rail news

View all News

rail industry focus

View all News

last word

Encouraging youngsters to be safe on the railway

Encouraging youngsters to be safe on the railway

This summer, Arriva Group's CrossCountry and the Scout Association joined to launch a new partnership to promote rail safety among young people. Chris Leech MBE, business community manager at the TOC, gives RTM an update on the innovative scheme. Recognising that young people are more likely to take a risk trespassing on railway tracks, C... more > more last word articles >


Andrew Haines, CE of Network Rail, tells BBC News his organisation could issue future rail franchises

24/06/2019Andrew Haines, CE of Network Rail, tells BBC News his organisation could issue future rail franchises

Andrew Haines, the Chief Executive of Network Rail, has told the Today programme on Radio ... more >

'the sleepers' daily blog

On the right track, Sulzer is awarded RISAS accreditation for Nottingham Service Centre

29/06/2020On the right track, Sulzer is awarded RISAS accreditation for Nottingham Service Centre

Following an independent audit, Sulzer’s Nottingham Service Centre has been accepted as part of the rail industry supplier approval scheme (RISAS). The accreditation reinforces the high-quality standards that are maintained by Sulzer’s network of independent repair facilities across the UK and further afield in its global network. ... more >
read more blog posts from 'the sleeper' >


The challenge of completing Crossrail

05/07/2019The challenge of completing Crossrail

With a new plan now in place to deliver Crossrail, Hedley Ayres, National Audit Office manager, major projects and programmes, takes a look at ho... more >
Preparing the industry to deliver trains for the future

04/07/2019Preparing the industry to deliver trains for the future

The move to decarbonise the rail network involves shifting to cleaner modes of traction by 2050. David Clarke, technical director at the Railway ... more >
Sunshine future beckons for South Wales Railways, says 10:10 Climate Action’s Leo Murray

02/07/2019Sunshine future beckons for South Wales Railways, says 10:10 Climate Action’s Leo Murray

Smart electrification is the way to boost clean energy resources, argues Leo Murray, director at 10:10 Climate Action. Contractors are clear... more >
Ambition doesn’t have to be expensive, says Midland Connect's Maria Machancoses

02/07/2019Ambition doesn’t have to be expensive, says Midland Connect's Maria Machancoses

The TCR Midlands conference is only days away and tickets are going fast for the sector event of the year at the Vox Conference Centre in Birming... more >