London Underground has taken one of the biggest steps in years towards running more and faster trains by naming Bombardier Transportation preferred bidder to overhaul the signalling on some of its oldest sections.

The new signalling system will increase the capacity of the Circle and Hammersmith & City lines – which include sections dating back to 1863 – by 65 per cent. It will increase the District line’s capacity by 24 per cent and the Metropolitan’s by 27.

The resignalling of the lines – together known as the sub-surface lines because they are in shallow, twin-track tunnels – is so central to the system’s upgrade that Tim O’Toole singled it out for special attention when leaving as LU’s managing director in 2009.

Londoners should “scream bloody murder” if the plans were to be scaled back or postponed, he said during a valedictory speech.

Since Bombardier is still only the preferred bidder, the parties gave no details of the size of the contract. But there has long been speculation that the project – which is to cover 40 per cent of the Underground’s route miles – would cost about £1bn.

“This is a major step forward in our plan to upgrade the Tube and will mean faster, more frequent and reliable Tube services for Londoners,” Mike Brown, LU’s managing director, said.

The system should be installed between 2013 and 2018. Bombardier – a shareholder in the Metronet public-private partnership consortium that collapsed in 2007– is already supplying S Stock trains that are replacing existing trains on the Metropolitan line.

The signalling system will be installed first on the Metropolitan, then the Circle and Hammersmith & City and finally the District line – in the same order that the new trains are being introduced.

The system will have a dramatic effect on central areas of the network around the Circle line because so many movements at the line’s junctions take trains across paths of trains heading in other directions. Under the new system, trains heading in conflicting directions ought to be held up for far shorter spells.

The Bombardier system to be installed will be compatible with the new system on the Jubilee line, says London Underground. The two lines share a depot and some tracks at Neasden.

LU put emphasis in the tender for the contract on ensuring there were fewer weekend closures to install the new signalling than were necessary on the Jubilee line.

Get alerts on London Underground Ltd when a new story is published

Copyright The Financial Times Limited 2019. All rights reserved.

Comments have not been enabled for this article.

Follow the topics in this article