'Diggory' gets to work at Castlerigg

Meet ‘Diggory’ – he’s United Utilities’ latest recruit to join the £300m West Cumbria water supplies pipeline scheme.

At 2.8m tall, with 40 teeth and weighing in at 54 tonnes he’s no ordinary worker – he’s a multi-million pound tunnel boring machine.

On Wednesday (22 August) he will be lifted by crane into the bottom of a purpose-built shaft just off the A591, ready to begin an epic tunnelling journey underneath Castlerigg.


Using laser guiding and GPS location technology, Diggory’s support team will be able to construct the 1.3km tunnel to millimetre accuracy, helping to pave the way for the twin water pipelines being laid between Thirlmere reservoir and Williamsgate.

The mighty machine was aptly nicknamed Diggory by the children at St Herbert’s School in Keswick. Their artwork is going to be printed up in pride of place on the safety hoardings surrounding the tunnel access sites in and around Keswick.

Diggory can shift as much earth in a day as 100 workers, and he’s going to be working around the clock to complete the Castlerigg tunnel by December 2018.

John Hilton, Project Director at United Utilities, 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 65 metres 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 45 kilometres 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 tunnel boring machine to be used on the pipeline project. His smaller sister, Druzella, began work last week digging a shorter tunnel beneath the River Greta in Keswick. When she has finished she will be used to dig another three tunnels at Chestnut Hill and Nether Place in Keswick and at the River Derwent near Cockermouth.

Diggory is a brand new machine, made in Germany especially for the Castlerigg job. When he has finished he will be reconditioned and sent to construct another tunnel in Australia.

The £300m West Cumbria Water Supplies project will bring more reliable and sustainable water supplies into Allerdale and Copeland. The scheme will link the area to Thirlmere Reservoir, and involves the construction of 100km of new pipeline, a new treatment plant at Williamsgate, two new pumping stations and two new underground service reservoirs. The project started in Spring 2017 and will be completed by 2022.