Barn Elms Combined Sewer Overflow Connection Tunnel

As part of works on the west section of the Thames Tideway Tunnel scheme, Barhale were contracted by the BAM Nuttall Morgan Sindall Balfour Beatty (BMB) joint venture to construct a series of complex underground structures that would intercept the sewage overflows from the West Putney Storm Relief Sewer for transfer to the main Tideway tunnel beneath the River Thames.

The scope of works included the construction of a 35m deep x 6m internal diameter drop shaft and a 210m long x 3m outside diameter connection tunnel.

Surface level works include 6m deep reinforced concrete (RC) interception chambers, a RC culvert and a RC MEICA building, comprising of electrical intake room, telemetry room and control room for system alarms and automated actuated valves (installed by others).

Barhale also built an 800m long, 4m wide access road, and installed additional sections to address Environment Agency and Local Authority requirements related to existing flood defences and protected trees in the proximity of the works.