Rollout of new Elizabeth Line trains stalls on Heathrow branch due to train signalling troubles

The first new train entered passenger service last year
The first new train entered passenger service last year (Source: TfL)

The rollout of new Elizabeth Line trains on the Heathrow branch of the Crossrail route has been delayed because testing them with the new signalling system has been complex, and taken longer than expected.

Transport for London (TfL) had hoped to roll out Elizabeth Line trains on the branch down to Heathrow from May, but that is now expected to be months later than planned.

In January, TfL had said contingency plans were being drawn up to deal with issues posed by the complexity of train signalling and software. And it has since been confirmed that those will go ahead, after the immaturity and instability of train software proved a problem.

Read more: Crossrail latest: New Elizabeth Line trains tested ahead of December launch

In late May, TfL Rail services between Heathrow and Paddington commence, taking over the current Heathrow Connect service.

The plan was to introduce new trains on the TfL Rail services Paddington-Heathrow in May
The plan was to introduce new trains on the TfL Rail services Paddington-Heathrow in May (Source: TfL)

Passengers will get the same service they currently get, with TfL aiming to deliver improved service, but it now won’t be until near the end of this year when four new Elizabeth Line trains an hour will run the route.

This is then expected to lift to six trains in 2019.

TfL’s supplier Bombardier is fitting trains with signalling equipment required for operating on the Heathrow branch, and TfL had said the contingency plans would come into play if Bombardier was unable to complete testing in time for May.

TfL will now operate the existing trains to provide the two train an hour service to Heathrow, as exists at present, supplemented by a two-train per hour service between Paddington and Hayes and Harlington. The latter will use new Elizabeth Line trains.

When the service is fully operational in December 2019, Elizabeth line trains will provide a direct link between the airport and central London destinations including Bond Street, Liverpool Street and Canary Wharf.

Read more: Elizabeth Line extension progress: TfL starts talks with Network Rail

Howard Smith, TfL’s operations director for the Elizabeth Line, said:

Our supplier Bombardier continues to test the Elizabeth Line trains and the new signalling system in the Heathrow tunnel.

While this takes place we will operate the same service pattern (two trains per hour) to Heathrow as exists now, using the existing Heathrow Connect trains.

We will also run two trains per hour between Paddington and Hayes & Harlington, which is the same frequency as now, using the new Elizabeth line trains. Once Bombardier has completed testing we will increase the frequency to Heathrow to four trains per hour later this year.

The big launch of the Elizabeth Line is planned for December this year, when the central London section opens, though the £14.8bn Crossrail project has faced escalating time and cost pressures as it gets to the crunch stage of the new railway's development.

Elizabeth Line planned timeline

Stage one: Trains start operating from Liverpool Street to Shenfield – June 2017 (TfL Rail)

Stage two: Trains start operating from Heathrow to Paddington (main line platforms) – May 2018 (TfL Rail)

Stage three: Trains start operating from Paddington (Elizabeth line platforms) to Abbey Wood, through the new central tunnels – December 2018

Stage four: Trains start operating from Paddington (Elizabeth line platforms) to Shenfield – May 2019

Stage five: Full through service (including Elizabeth line services to Reading) – December 2019

Read more: Mapped: How the Elizabeth Line will open in stages

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