The tunnel will be capable of transporting up to 20 million tonnes a year of polyhalite, a naturally occurring multi-nutrient fertiliser. An underground conveyor belt will connect the company's new multi-billion pound mine near Whitby, to a purpose-built processing and shipping facility in Redcar for distribution globally.

The main parts of the 225m long machine arrived at AV Dawson's Heavy Lift Port on the Teesside Docks from a specialist factory in western Germany. It was then moved in convoy through Middlesbrough to the Sirius Minerals construction site at Wilton International, where the machine will be reassembled and used by contractor Strabag, which also worked on the 35-mile Gotthard Base Tunnel under the Alps.

"The arrival of our first tunnel boring machine represents an exciting milestone for the company and the region. We continue to make good progress delivering our world-class project, as we invest in the local area and create jobs and supply chain opportunities," said Gareth Edmunds, external affairs director at Sirius Minerals.

The machine will bore the first of three separate tunnel drives which will make up the 37km tunnel from the mine, near Whitby, to the Teesside processing facility. Two other machines are planned to be launched in 2020 from Whitby and Lockwood Beck, near Guisborough, to complete the final 15 miles of the 6m diameter tunnel. Each TBM will operate 24 hours a day, 7 days a week, lining the tunnel with concrete segments as they go.