The vertical shaft sinking machine has finished its work at Woodsmith Mine, excavating the access shaft for Sirius Minerals transport system to 115m and setting a new VSM world record in the process. The shaft will now be excavated using traditional techniques to the full 360m depth.
To construct the initial 120m of the 360m deep MTS shaft at Woodsmith Mine as efficiently, expediently and safely as possible, specialised innovative equipment was deployed for the first time ever in the UK.
The application of the Vertical Shaft Sinking Machine (“VSM”) technology – developed by leading mechanised tunnelling equipment manufacturer Herrenknecht – enabled the sinking of the shafts through near-surface water aquifers, due to the fact that the machine is designed to work underwater with a shaft lining being lowered behind.
Typically, shaft lining would be created from pre-cast concrete segments but, in conjunction with contractors Careys Civil Engineering and Joseph Gallagher Limited, Sirius utilised a new ‘slip form’ technique to pour the concrete lining. Using this technique, by continuously pouring the shaft walls simultaneously with the VSM’s excavation activity, the team was able to line the shaft more safely, rapidly and cost-effectively. Cutting-edge 3D, 4D and virtual reality (VR) modelling technologies were also used to digitally construct the shaft, forecasting a range of possible outcomes for each aspect of the construction process.
The machine reached a depth of 115.2m, setting a new world record for this type of excavation in the process - the previous record was 84m - testament to the groundbreaking, innovative approach taken to constructing the project.