The world tunneling record for the longest single tunnel boring machine drive (TBM) was set in England in December when STRABAG’s tunneling specialists reached the 25.8 km (16 mile) mark on a tunnel drive for the Woodsmith Mine near Whitby in northeast of England.
The team is excavating a 37 km (23 mile) tunnel beneath the North York Moors National Park with a Herrenknecht TBM. The 1,775-t (1,956 st) machine with a diameter of 6 m (20 ft), named Stella-Rose, has been boring underground for around four and a half years.
The Woodsmith project will be the world’s longest conveyor tunnel for a permanent mineral transport system (MTS) on behalf of Anglo American. When completed, the MTS will be used to transport ore from the world’s largest polyhalite deposit from under the North York Moors National Park to Wilton, Teesside, for further processing. Polyhalite, a naturally occurring mineral that can be used as a fertilizer in organic farming, is extracted from the Woodsmith Mine via two 1.6-km (1 mile) shafts connected to the underground conveyor belt, a system which was chosen to minimize the environmental impact at the surface. With an internal diameter of 4.9 m (16 ft), the conveyor tunnel and transport system are designed to handle a throughput of up to 20 Mt/a (22 million stpy) of material.
Following completion of the overall project, Anglo American and STRABAG expect to have the record officially confirmed by Guinness World Records. About 450 people are directly employed on the Woodsmith project, with around 75 percent of them local to Teesside. STRABAG’s preference for working with local construction partners and suppliers has also created many further jobs in the region.
“We are extremely proud of the team at the Woodsmith project for reaching this incredible milestone and 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,” managing director of STRABAG UK, Simon Wild said in a statement.
“We are delighted to achieve such an incredible milestone in the UK as part of our pioneering project. It is a demonstration of the fruits of teamwork with our partners. We are now focused on looking forward and setting a new world record every day. The Woodsmith tunnel is a fundamental part of our commitment to create a sustainable mine with minimal environmental impact,” Andrew Johnson, Woodsmith Project Director for Anglo American said.