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Thames Tideway completed after final lid lift (video)

An aerial shot of a construction site with a yellow crawler crane and a large blue gantry crane
The 1200-tonne, 45m-wide concrete lid is lowered onto the shaft at Abbey Mills Pumping Station, Stratford.

Underground construction on London’s super sewer, including its tunnels and shafts, is now complete following the lifting of a concrete lid over the shaft at Abbey Mills Pumping Station in Stratford.

This final, major construction work on the project saw a giant, 24m-wide, 1,200-tonne circular concrete ‘lid’ placed over the shaft at Abbey Mills Pumping Station in Stratford using a purpose-built gantry crane and other manoeuvring equipment, for five hours during Easter.

The manoeuvre represents the heaviest lift on the super sewer project – even surpassing the lifting of Tideway’s six tunnel boring machines early in the programme.

The shaft at Abbey Mills is the deepest on the project at 70m, and is the point at which the super sewer connects to the Lee Tunnel, which was completed in 2016.

Thames Tideway CEO Andy Mitchell said: “This is the moment we’ve all been waiting for. The underground civil engineering on the Tideway project is now complete following eight years of dedicated hard work from all our teams working in the capital

“There is still work to do – we need to finish some above-ground structures and, crucially, test the system – but this nonetheless marks an absolutely critical milestone for the Tideway project and London.”

The super sewer, known formally as the Thames Tideway Tunnel, is a 25km-long sewage tunnel designed to dramatically reduce sewage pollution in the central London River Thames. 

In a typical year, tens of millions of tonnes of storm sewage spill into the River Thames. Once fully operational, the new infrastructure will reduce those spills almost completely.

And now, the project is closer than ever to its ultimate goal of improving the health of the Thames – after a 1,200-tonne concrete lid was lifted on top of a deep shaft in Stratford.

Tideway, the company building the super sewer, has now built the full 25km, 7.2m-wide main tunnel, a 4.5km connection tunnel in south-east London, and a 1.1km tunnel in south-west London.

Following the successful delivery of this final milestone, Tideway will begin the process of ‘commissioning’ the system – ensuring the new infrastructure functions as designed – this summer before bringing it into full operation in 2025.