How is the Thames Tideway Tunnel being built?

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As befits one of the world’s great capital cities, the Thames Tideway Tunnel is the biggest infrastructure project ever undertaken by the UK water industry.

The Lee tunnel.

The Lee tunnel.

Most of the engineering work is being carried out by a company called Bazalgette Tunnel Ltd (trading as Tideway).

The 15-mile-long tunnel will mainly follow the course of the Thames through London, so it can intercept sewage from the ‘combined sewer overflows’ (CSOs) which are currently polluting the river. At a depth of up to 65 metres, it will be London’s deepest tunnel and pass underneath the rest of London’s infrastructure.

There are three main construction sites at Fulham, Battersea and Bermondsey, with a number of other smaller sites where work will also take place. Each of the three main ‘drive sites’ will have its own tunnel boring machine to dig a section of tunnel, seven metres in diameter, using a rotating cutter-head, and lining the wall with concrete segments as it goes.

Construction works by Tideway started in 2016 and the finished tunnel will be handed over to Thames Water to operate in 2024.

Useful websites

To find out more about how the Thames Tideway Tunnel is being built, please see the link below.

Visit the Tideway website