Colne Valley Viaduct & Chiltern Tunnel



Montant des travaux

£965 million


Civil engineering design




London - UK

Project overview:

The construction of 160km of rail tracks using twin-bored tunnels and green tunnels, viaducts and engineering earthworks to achieve a technically viable and environmentallysensitive solution. HS2 Phase 1 is the expansion of the high-speed rail network between London (Euston Station) and Birmingham. HS2 will run north-west on the Colne Valley south embankment which will be approximately 190m long and up to 10m high. It continues the 3.4km long Colne Valley viaduct across four lakes: Harefield No.2 lake; Savay Lake; Korda Lake; Long Pond; Broadwater Lake, which houses a Nature Reserve, and the River Colne. The line then passed onto the Colne Valley north embankment which will be approximately 290m long and up to 12m high. The Chilterns Tunnel is a 15.8km bored tunnel. There will be four vent shafts and one intervention shaft located along the proposed line of route – Chalfont St Peter, Chalfont St Giles, Amersham, Little Missenden and Chesham Road. Its southern portal is located near Maple Cross. Its site will also house a compound during construction with all material from the bored tunnel coming here to be treated prior to being used elsewhere along the line of route. The northern portal is adjacent to South Heath.