HS2

Northern Line Extension enabling works completed ahead of schedule

The first phase of enabling works on the London Underground Northern Line Extension has been completed ahead of the planned 19 week schedule.

Amey engineers designed and installed eight articulation joints along a 55m section of the South West Storm Relief Sewer, which will allow it to flex during the excavation and construction of the extension’s 5.2m-diameter running tunnels.

The works also required the diversion of flow to provide safe and adequate access and egress for operatives, materials and equipment.

Kevin Fowlie, managing director of utilities at Amey, which acted as a subcontractor for the Ferrovial Agroman and Laing O'Rourke (FLO) joint venture holding the contract to build the extension, said: “Our approach to these works was based on a methodology used on another successful project previously carried out by Amey on the North East Storm Relief Sewer.

“Drawing on our experience in this way ensured that we were able to minimise delays and support the project's wider schedule and performance indicators.”

Jonathan Cooper, project manager at NLE Tunnels & Utilities, added that Amey and FLO had worked “incredibly hard” on the works. Phase two of the enabling works, including settlement remediation, is due to start in 2018.

The extension will include two new stations at Battersea Power Station and Nine Elms, due to be completed in 2020. It is intended to support 25,000 new jobs and 20,000 new homes.

However, concerns were raised about the state of the project after it emerged that redesigning Battersea Power Station would add an extra £240m to the costs.

Last year, the Independent Investment Programme Advisory Group warned Transport for London that the project “remains of high concern” because of the risk of delays.

(Image c. Loco_Steve from Flickr)

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