A 10-year-old girl with a passion for construction has carried out a special site visit ahead of innovative tunnelling work on a multi-million pound UK water engineering project.

Northumbrian Water is set to install a tunnel beneath the River Tees in north-east England, to enable a new £155m water pipeline to be constructed while protecting the watercourse and the wildlife that relies upon it. Project Pipeline: County Durham and Tees Valley will see the construction of around 57km of new pipes connecting Lartington Water Treatment Works with around 200,000 customers.

A specialist tunnel-boring machine has now arrived on site, ready to begin its journey between the bottoms of two specially-constructed shafts, to create a pathway beneath the river, through which the new pipes can be installed. The arrival was greeted by 10-year-old Penny Green, who won a competition to name the machine, run by Farrans Construction, the water company’s partner in the project’s delivery.

She chose the name Penelope – after herself, because “the machine must be strong like me", and was joined by her family at the eastern shaft to see the machine and meet the team.

Penny said: “I was great to see Penelope the tunnelling machine, with her name – and my name – on the side. I chose the machine, because it must be strong, like me, to create a tunnel all the way under the River Tees.”

In recent months, work has been carried out to create the two shafts, one on either side of the river. The western shaft is eight metres in diameter and 32 metres deep, while the eastern shaft is 7.5 metres in diameter and 46 metres deep, the difference being due to the rising topography on the east bank.

A 221-tonne concrete base has been constructed in each shaft – a volume equivalent to 15 wagons of concrete. This 220m journey beneath the Tees will take up to six weeks to complete, going from east to west, before a large crane will lift the machine back out of the eastern shaft.

James Dawes, Northumbrian Water’s project manager said, “This project has been years in the planning, and ensuring that key strategic crossings, such as the River Tees, are done in the best way possible for the local environment and communities, has been vital.

“When it came to the challenge of how to cross the Tees, we had to consider such factors as how this would impact the stunning Teesdale landscape that will be here long after our team have completed the project and moved on, and the river’s ecology.

“The use of no-dig techniques, such as tunnelling or directional drilling, is becoming increasingly common in our projects, to reduce the impact on our region’s road and rail networks by reducing the need to dig long trenches. However, this is the first time we have employed it to cross a large river."