THE 20-year old project to extend the East London Line took a decisive step forward last month when Transport for London invited bidders to prequalify for the main infrastructure works contract for Phase 1.

Described as the organisation's 'flagship project' by Howard Smith, Chief Operating Officer of TfL London Rail, responsibility for the ELL extension was transferred to TfL on November 12 2004.

Due for completion in June 2010, Phase 1 will provide services between Dalston Junction, New Cross, Crystal Palace and West Croydon. The main contract will cover design, construction and commissioning of civil works, track, electrification, signalling and telecommunications over the 10·8 km between Dalston Junction, New Cross and a grade-separated junction with Network Rail's London Bridge - West Croydon route at New Cross Gate.

New infrastructure is needed to link London Underground's existing ELL north of Whitechapel station and a currently-disused 3 km section of railway alignment leading to Dalston Junction. New stations are to be built at Shoreditch High Street, Hoxton, Haggerston and Dalston Junction.

The existing route will be rebuilt to Network Rail standards, including 750V DC third rail electrification, with new signalling able to deliver a design headway of 24trains/h. Train detection will use axle-counters, and TPWS will be fitted to every signal. The line will be controlled from a new signalling centre at New Cross Gate, where there will also be stabling for 20 four-car trains.

Following prequalification, TfL expects to shortlist up to five bidders in September 2005. Final tenders will be due in January 2006, from which two bidders will enter final negotiations before the contract is awarded in June 2006. The contractor is expected to start work in November 2006, once a second package of enabling works being undertaken by Taylor Woodrow for £30m has been completed.

Network Rail will be responsible for operational control of the extended East London Line. TfL will procure the rolling stock, probably existing suburban EMUs, and award the train operating franchise.