The Tyne crossing project - one of the UK's largest construction projects - has got underway in the North East.
This new crossing will be a two-lane below the River Tyne to accompany the two nearby tunnels - a similar existing one for vehicles as well as a pedestrian and cycle tunnel.
It might not be a vast stretch at just 1.5km long, but the project is squeezing in a variety of tunnelling methods into the four year construction period, which is expected to complete in December 2011.
Along the way, the build will see steel and concrete piling, concrete diaphragm walling, immersed tunnel element casting, tunnel mining (with sprayed concrete lining) all come together to create the new crossing.
The new tunnel is expected to be open by December 2010, at which point, traffic will be diverted through it from the existing tunnel while it is closed for a one-year refurbishment.
The old tunnel is a deeper, rock bored two-lane tunnel opened in 1967. Once the project is complete, this will then carry northbound traffic while the new tunnel takes traffic south.
This £260M scheme is the first UK project for the French main contractor Bouygues Travaux Publics. It will be subcontracting out the construction work to a number of firms during the build period. HPR is principal designer and is joined by consultants Faber Maunsell and Parsons Brinckerhoff for the main design work.
When open, it is expected to be the UK’s first newly built tunnel to be fitted with a mist sprinkler system for fire safety.