24 August 2005

Network tests for new signalling systems

Elements of brand new signalling systems for the Jubilee and Northern lines are being tested on the Underground by Tube Lines, the company rebuilding the Tube’s busiest lines. Trials are taking place at Bermondsey and will be followed by further trials at Willesden Green on the Jubilee line and at Finchley Central on the Northern line.

Tube Lines is investing £600 million to install new signalling systems on both lines to deliver a 20% improvement to each line’s capability. For passengers, this will mean trains running more frequently and at increased speeds, leading to more reliable, safer and faster services. The first stage of testing was completed to plan at Tube Lines’ dedicated test track facility at Highgate, North London last year with work ongoing since then.

Alcatel is providing the new loop-based signalling system which uses computers and antennae on trains to communicate with cables laid on the track, giving precise details about each train’s location and speed. These connect with control centres for each line, from where all trains will be controlled. The technology, Alcatel’s SelTrac® S40, was chosen because it is tried and tested on urban railways around the world, including in Vancouver, Kuala Lumpur, Hong Kong and in London on the Docklands Light Railway, although none present such a challenging environment as the London Underground.

Trials of specific elements of the new system are now taking place under controlled conditions on the actual Underground network. At Bermondsey Tube Lines and Alcatel are checking how existing railway components like track circuits and passenger edge door controllers impact on the strength of the signal between the track loop and train antennae. During night time engineering hours when passenger services do not run, a test train fitted with antennae and an on-board computer is being manually driven along the track where cables have been fitted. Recordings are being taken to validate theories.

At Finchley Central Tube Lines and Alcatel are looking at how the cable of the track loop can be positioned so that maintenance machinery used on overground sections does not disturb it and how it should be laid over points and crossings. The trials at Willesden Green are twofold: firstly, the reliability and accuracy of axle counters are being checked, which help confirm the location of trains; and secondly, engineers are developing a method for switching between existing and new signalling systems quickly and efficiently to enable later stages of testing.

The sites were chosen as they represent some of the typical conditions found on the two lines, for example overground sections and modern tunnels. Further trials will take place in the future to check how the system works in other conditions, for example the older tunnels of the Northern line’s tube sections.

Siv Bhamra, who is overseeing the upgrade of the Jubilee and Northern lines for Tube Lines, said:

“We are making good progress towards replacing the signalling systems on the Jubilee and Northern lines and the project is running on schedule for implementation in 2009 and 2011 respectively. There’s still a lot of work to do as it’s a hugely complicated process but so far our tests show the new technology working well.”

Mark Halinaty, General Manager of Alcatel’s transport automation activities in the UK, said:

“Following on from last year's successful demonstrations at the Highgate Test Track, these trials represent a further step in the planned overall risk reduction process. This process helps to ensure the successful and timely introduction of the proven SelTrac technology into the challenging London Underground environment.”

The new signalling system will be operating on the Jubilee line by 2009 and on the Northern line by 2011. On the Jubilee line, the upgrade project will be preceded and supported by the addition of a seventh car to the existing 59-train fleet, which will increase passenger carrying capacity by 17% - roughly 6,000 passengers per hour during peak in both directions. This will be implemented over Christmas this year – four years ahead of schedule.



For further information or photographs, please contact:

Tube Lines press office 020 7088 4848
Laura Wallace, Tube Lines 020 7088 5335 / 07843 551 589


Notes to Editors

  1. Tube Lines is responsible for the maintenance and upgrade of the infrastructure on the Jubilee, Northern and Piccadilly lines. London Underground is responsible for operating the Underground, for employing drivers and station staff, for ticketing and fares, and for the Tube’s safety regime.
  2. The Tube Lines consortium consists of two shareholders – Amey and Bechtel. They bring together some of the most experienced providers of business services with specialist skills in the rail industry, including track and signal renewals, plus project and operational management. They are providing some of the best project and operational managers from around the world to work on the modernisation of the Tube system. Amey owns two-thirds of Tube Lines’ business and Bechtel one third.


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