North Yorkshire polyhalite mine developer Sirius Minerals has reported significant progress on shaft construction and the start of tunnelling work in its latest quarterly report.
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“2018 was a year of significant progress for the company,” said Sirius managing director and CEO Chris Fraser. “Completion of procurement to support the stage 2 financing and the signing of an additional 4.8Mtpa of take-or-pay supply agreements, have been substantial achievements. Considerable progress has been made across all our construction sites and development activities are advancing at pace. More than 800 people are now employed on the project, demonstrating the transformational potential for jobs and growth in the local area.”
With manufacture of the first of three tunnel boring machines (TBMs) to be used by tunnelling contractor Strabag almost completed at Herenknecht’s factory in Germany, Sirius has said that cut and cover tunnelling work for the material transport system (MTS) is already underway. Sirius has reported that 13m of tunnel has been constructed so far and cut and cover techniques are planned to extend the tunnel to 125m to reach the competent Redcar Mudstone before the drive using the TBM starts. The TBM is expected to be delivered to site this quarter.
At the Woodsmith Mine site, Careys has completed the service shaft foreshaft excavation to 44m and is expected to reach the final depth of 45m in January 2019. The service shaft winder house basement is complete, with the connecting walls to the shaft and upper floor currently being installed.
The production shaft diaphragm walls have been completed by Bauer with 7.2km of diaphragm walls installed at the site.
The Herrenknecht vertical sinking machine (VSM) that is being used to construct the MTS access shaft was launched by Careys in October 2018 and has now reached 63m depth. Sirius has reported that advancement rates are now 25% higher than when the work first started and the company expects rates to further improve.
The only minor delay reported by Sirius is at the intermediate shaft site at Lockwood Beck where the company had hoped to start excavation by the end of last year. Bachy Soletanche has completed piling work for the temporary headframe to be used by shaft construction contract DMC Mining Services and construction of a 60m grout curtain at the site.