Tunnellers on the Woodsmith project near Whitby recently reached 25.8km on what will be the conveyor tunnel for a permanent mineral transport system.
This will be used to transport tens of millions of tonnes of polyhalite from under the North York Moors National Park to the coast before the fertiliser material is shipped around the world.
Strabag UK has been boring under the North York Moors National Park since June 2019 using a single hard rock Herrenknecht TBM to build the 37km tunnel with an internal diameter of 4.9m.
The former record was set by a water conveyance tunnel project in the Middle East, which was also built using a Herrenknecht tunnel boring machine.
Once completed, Strabag will have set a new world record on the Anglo American-funded project and are expecting this to be confirmed by Guinness World Records.
The tunnelling contractor directly employs 450 staff on the project, 75% of which are local to Teesside, and has also prioritised the use of local construction partners and suppliers, creating many more jobs for the region.
Managing director for Strabag UK, Simon Wild, said: “We are extremely proud of the team at the Woodsmithproject for reaching this incredible milestone and safely passing the current world record set for a single bored tunnel drive.
“This is another example of our growing presence in the north- east of England and the UK, demonstrating our industry leading expertise.”