Interviews

Silwood sidings set for five-car trains

Mike Stubbs, director at London Overground, discusses the completion of the Silwood sidings facility and the challenges faced by the contractors over the last 17 months.

Work to deliver a 25% capacity increase on the London Overground network has reached a milestone with the completion of the new Silwood sidings facility.

The site, near New Cross Gate, will provide overnight sidings for 10 five-car trains, and work to extend 13 station platforms to accommodate the running of these trains is also complete.

The first five-carriage trains will enter service later this year between Highbury & Islington and Clapham Junction / New Cross Gate / Crystal Palace / West Croydon.

Forming part of the larger £320m London Overground Capacity Improvement Programme (LOCIP), which includes the construction of longer platforms and the delivery of an extra 57 Class 378 carriages by the end of 2015, the work at Silwood to accommodate the new cars has been completed in just under 17 months.

The land used for the sidings was brownfield and used as a car compound – located within a ‘rail triangle’, with lines on three sides.

Crucial

London Overground director Mike Stubbs says the new sidings are “crucial” to the overall LOCIP, as without them, “we can’t have longer trains”.

He added: “At our main depot at New Cross Gate, currently we stable four-car trains and we have some of these stable sidings taking effectively three trains, so they are 12 cars long.

“If you extend your trains to five-car, you can get two trains in, with a bit of spare track – but you’ve got another train. So where are we going to put it? So, because the depot at New Cross Gate is very tightly constrained, we had to find somewhere else to take 10 trains, which were displaced out of the depot.”

Decontamination work

Describing the project’s timeline, Stubbs told RTM: “The first thing we had to do was dig it out and, as you can imagine, it was a brownfield site in south east London so we found lots of rubbish in there.”

Preparation of the contaminated three-hectare site involved the removal of 70,000 tonnes of spoil, levelling the entire site, before the team could lay 6,500 tonnes of ballast, 3.5km of track, 19 sets of points plus all the associated power, signalling and drainage works. The stabling sidings and associated access facilities occupy 1.5 hectares of the site.

Back in June 2013, Cleshar was awarded the design and build contract to construct Silwood siding, while Pell Frischmann undertook the multi-disciplinary design for the 10 roads for stabling the newly extended five-car trains. The project scope included new permanent way, accommodation, acoustic barriers and fencing around the sidings, DC traction power, low-voltage power supplies, lighting and CCTV.

The Cleshar project team has managed the design and construction of the 10 new roads, including a turnout from the main line and a crossover between the existing main line tracks. During this work, as well as all the new track, 350 lighting bollards, 320 lamp posts, 105 bulkhead lights and associated cabling and cable route management systems were installed.

Stubbs said: “We put the traction power in and signalled it, because it is a fully-signalled set of sidings. There are also walkways all around, and full lighting. So, as well as doing stable sidings, they [maintenance staff] can do train prep before going into service from there.”

The time challenge

Stubbs said: “We had to put in a crossover on the main line and then the turnout. They went in over Christmas last year, when we had a five-day block, and eventually they were signalled and connected up.”

He added that the biggest challenge faced by the contractors was time. “We took it from brownfield site to a fully-operational set of sidings in 17 months,” said Stubbs. “That was our biggest challenge.”

RTM was told that there had been a delay in getting the planning permission granted in order to start the work. “The reality was that we came up with one scheme, submitted the planning application and then designed it, costed it and found we couldn’t afford it,” said Stubbs.

“So we then did a revision to get the price within the budget, which meant we made it slightly smaller. So there were challenges of overlapping activities and getting it done on time.”

Cost and contractors

The Silwood project cost about £28m. And there were several contractors carrying out the work during the project timescale.

For instance, Cleshar did the design and build; ClancyDocwra the earthworks; and the signalling was designed by CH2M Hill/Halcrow and tested by SIMS. TfL also contracted Invensys, which is now part of Siemens, to do control work modifications for the facility’s signalling.

“They are all contracts we managed directly and had to make sure fitted together and worked,” said Stubbs. “But the bigger collaboration was not just with the contractors: it was with LOROL as the train operator; Bombardier as the train maintainer; and Network Rail too because the SCADA system for the siding is controlled from its control at Lewisham ECR (electrification control room) – so we had to get them on board as well – working to our tight timescales.

“It was a really good example of the industry working together to deliver an output.”

Platform and depot extensions

In line with the London mayor’s 2012 manifesto, London Overground trains will increase from four to five carriages by December 2014. “We’re well on track to do that,” said Stubbs. “The platform extensions are all done.

“The biggest thing to do now is the New Cross Gate depot where we’ve pushed the back of the maintenance shed out by 20m, so we can maintain the new five-car trains. We still have work to do, but we’re looking at having this done by early November.”

The first longer trains are expected to enter service on the East London Line (ELL) in late 2014. In total, 29 trains are being extended on the ELL, one a week for just over half a year. It is expected that the North London Line extensions and disused platform reopenings will be simpler than in phase 1. At stations where platform extensions were not a viable option to accommodate the longer trains, London Overground has introduced selective door operating, which will be facilitated by the open walk-through design of the carriages. This was required at Whitechapel (temporarily until Crossrail completes construction), Wapping, Rotherhithe and Canada Water as it is not possible to extend the platforms to the required length without completely rebuilding the stations. Train announcements will provide advance warning about which doors will not open once the longer trains are introduced

“On the ELL there were three platforms that couldn’t be extended economically, so we put selected door operation in and we have also taken the opportunity to put correct side door enabling in to eliminate the driver enabling the doors on the wrong side – so that all comes in later this year,” said Stubbs. “By the end of 2014 we’ll have a number of five-car trains running on the ELL, and then it’s quickly onto the North London line for next year.”

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