Work on United Utilities’ £300M West Cumbria water supply pipeline scheme has reached a key milestone with the tunnel boring machine (TBM) for the Castlerigg tunnel launched yesterday.
The Herrenknecht TBM – named Diggory – will drive the 1.3km tunnel below Castlerigg to the east of Keswick on the new 100km pipeline scheme to connect Thirlmere Reservoir to water users in West Cumbria.
The 2.8m diameter, 54t TBM was lowered into a shaft off the A591 yesterday and will work around the clock to complete the tunnel drive by December this year.
United Utilities project director John Hilton said: “This is an exciting milestone in the West Cumbria Supplies project. The Castlerigg tunnel is the longest along the pipeline route, and the deepest in places where it will be up to 65m below the surface. We have an excellent team of specialists working with us on this particular tunnel and the four others along the route.
“I’m hopeful that we will continue with the amazing progress we’ve been making this summer. The dry conditions have allowed us to get 45km of pipeline in the ground and we’re forecasting to complete about a year ahead of schedule, and we’re also under budget.”
Diggory is the second TBM to be launched on the scheme. A smaller TBM, named Druzella, was launched last week to drive a shorter tunnel below the River Greta in Keswick and will also be used to drive a further three tunnels on the route at Chestnut Hill and Nether Place in Keswick and at the River Derwent near Cockermouth.
Diggory will be reconditioned at the end of the project and is set to be used on a scheme in Australia.