Design complications have pushed back the next stage of the procurement process for the £263M Barking Riverside extension scheme by five months.
Invitations to tender for the project, which will lengthen the London Overground line east of the capital, had been expected this September but Transport for London has now admitted they will not go out until February 2018. The contract award had been expected in “late spring” but it will now be announced slightly later in “early summer”.
Balfour Beatty, Carillion and Volker Fitzpatrick were shortlisted last year for construction of the extension project, which will involve 1.6km of new track.
Complications around traction power and topographical surveys have been blamed for the design delay. After the scheme was given the green light in August, detailed site investigations across the proposed route uncovered pockets of poor ground conditions that would make it difficult to support the rail track.
A decision to switch power provision for the line from a substation in Barking to a larger station in West Ham with more capacity has required extra assessment work, further delaying completion of the design phase, which is being carried out by Arcadis.
“We have met with the designers to escalate this with senior management,” said TfL in recently published investment documents.
Timescales for Network Rail – responsible for asset protection and maintenance once the scheme is complete – to review the preliminary designs were being “closely managed”, added TfL.
The transport body stressed that at this stage the delay had not affected the overall construction programme.
A spokesperson for TfL said: “The design stage is coming to a close, which will allow the next stage of this fully-funded project to progress. Construction of the link will begin next year and train services are still planned to start in 2021.”
The Barking Riverside extension will add 4km to the London Overground Gospel Oak to Barking line, the electrification of which has been mired in cost and disruption issues, and add a new station at Barking Riverside. It is anticipated to unlock development potential for 10,800 homes in the area.
Arcadis declined to comment.