The engineering

Last updated: 25 February 2015

The engineering

At 25 kilometres long, up to 65 metres deep, and more than seven metres in diameter, the Thames Tideway Tunnel will be the biggest infrastructure project ever undertaken by the UK water industry.

It will generally follow the route of the River Thames to enable it to connect to the combined sewer overflows (CSOs) that are located along the riverbanks, passing underneath all other infrastructure in London and through a variety of different ground conditions.

The route and tunnel

Routeandtunnel 10


The Thames Tideway Tunnel will be built by world-class contractors using the best innovative techniques to offer the most sustainable and cost-effective methods of construction.

There will be three main ‘drive sites’ where tunnel boring machines are lowered in to the ground and driven below the river bed to construct the tunnel from the east, west and central locations.

Innovative engineering in the design phase has already reduced the tunnel from the initial 32 kilometres proposed, down to 25 kilometres, and reduced the number of construction sites needed from 45 to 24.


What is a tunnel boring machine?

A tunnel boring machine (TBM) excavates a circular tunnel using a rotating cutterhead, while simultaneously creating a tunnel wall using concrete segments. As it excavates it also transports material from behind the machine via a conveyor belt or pump, which is progressively extended as the machine moves.

Key part of a TBM

Keypartsoftbm 10


The construction plan

Jobs & opportunities

Current positions available within the Thames Tideway Tunnel project include:

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    News on procurement

    The latest procurement news and updates

    24 April 2014

    Final construction procurement package released for Thames Tideway Tunnel

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    10 June 2014

    Investors sought for new company to own UK’s biggest water industry project

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    07 July 2014

    Thames Tideway Tunnel to host event for SCADA specialists interested on working on the project

    Read on