THAMES TIDEWAY TUNNEL
Thames
Tideway Tunnel - Our Plan
and Grands Projects Bachy Soletanche , has the east contract .
The engineering marvel that is the TTT is 25 kilometres long , descends 30 metres at its western end and 66 metres at its eastern and is over seven metres in diameter . The TTT will be the biggest infrastructure project ever undertaken by the UK water industry . It will follow the route of the River Thames connecting to the combined sewer overflows located along the riverbanks . En route , it will travel underneath all other London infrastructure and through a variety of different ground environments .
It will be dug out by German-made , underground-conditioned , tunnel boring machines ( TBMs ). These extrude the excavated material , which is removed with a conveyor belt or , in wetter places , a slurry pipeline . As excavation advances , the tunnel is encased in a concrete shell using precast segments . The TBMs are introduced through a vertical shaft . Later , the existing overflow shafts will be connected to the great tunnel ,
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