New Signalling System for Piccadilly Line

But £160m contract gives little sign of tubes stopping at Turnham Green

Tube Lines, the company responsible for rebuilding a number of London Underground line, has awarded a £160m extension to the contract it has with Thales’s to provide a new signalling system on the Piccadilly line by 2014.

The new system will use information technology to enable trains to safely run faster and more frequently. Together with a new fleet of trains, it will result in a 20% increase in capacity and improved reliability.

Parts of the existing signalling system are over 40 years old on the Piccadilly line, which celebrated its one hundredth birthday in December 2006. Although the existing signalling system makes use of computers, it relies heavily on mechanical and electrical components which are difficult to maintain and operate reliably. The new system, Seltrac, uses computers fitted to each train which interact with an induction loop between the tracks, showing the train’s location within centimetres. The computer relays this information to a control centre, which responds with messages telling the train how fast to go in order to maintain the most efficient speed and a safe distance from the train ahead.

However, the system does not automatically signal the advent of Piccadilly line trains stopping at Turnham Green. The lines between Barons Court and Ealing Common, where the Piccadilly and District lines share the facilities are controlled by Metronet not Tube Lines and whilst Metronet do have an ongoing rebuilding programme, it is not expected to be completed until 2016.

One of justifications from the tube companies for the Piccadilly Line not stopping at Turnham Green has been that the antiquated signals do not make this practical. ChiswickW4.com asked Tube Lines’ George Hutchinson for a comment and to date has received no response.

February 6, 2007