First TBM (length 225 m, weight 1,800 t), after final checks in Germany, is ready to be shipped to Wilton International, Redcar. The TBM will be reassembled and start tunnelling in the second quarter of 2019. It will work on the first drive for the 37 km Sirius Minerals’ underground mineral transportation systems (MTS) between Woodsmith potash mine, near Whitby, to a processing facility on Wilton International in Redcar. The tunnel for MTS is being built in three sections and it will be passing through one consistent and well-known rock strata.

The first 13 km drive was secured by Strabag, and construction began in December 2018 and will run from Wilton to an intermediate shaft at Lockwood Beck in the south. The first 125m of the tunnel is created with traditional tunnelling methods, before the TBM takes over for the rest of the 13 km from Wilton.

Two more TBMs are planned to be launched in 2020 from Whitby and Lockwood Beck, near Guisborough, and these will complete the final 23 km of the 6 m diameter tunnel. Workers will operate the TBM 24 hours a day, 7 days a week, lining the tunnel with concrete segments as it goes.

When complete, the tunnel will transport up to 20 million tonnes a year of polyhalite ore on a conveyor belt from the mine, to a purpose-built processing and shipping facility in the shadows of the old Redcar Steelworks, for distribution around the world. Polyhalite is mineral that combines the elements potassium, sulphur, magnesium and calcium.

The underground transportation system, linked to the mine, was chosen as the transport solution to avoid impacting the local landscape and will have no impact on the ground above, sitting at an average of 250-m below ground level. Sirius wants to achieve production capacity of 10 million tonnes a year by 2024.

Click here for the video, uk/97 for the tunnelbuilder archive. Visit https://siriusminerals.com. 07/19.