Careys uses innovation to help construct Woodsmith Mine’s MTS shaft

In this instalment of our ongoing series about our contributions to this landmark project, we’ll examine how Careys Civil Engineering – with the invaluable support of the digital engineering experts from our in-house Careys Design Team’s – has used an innovative approach to help construct the initial 120m of the vital 360m material transport system (MTS) shaft.

The North Yorkshire polyhalite project represents the first significant mining operation in the UK since the 1980s. This ambitious, approximately £3bn venture aims to extract the mineral polyhalite from the planet’s largest and richest vein, which sits over 1,500m beneath the ground in a national park near Whitby, Yorkshire.

Along with building the foreshafts of the service and production shafts, we are responsible for constructing the crucial MTS shaft. Once completed, this shaft will offer access to the 6m-wide, MTS tunnel, which sits at an average of 250m below ground level, along which the polyhalite will be transferred 37km to a processing plant and purpose-built port facility at the Wilton International site in Teesside. From there, the mineral will be shipped out to various destinations across the world, where it is in high demand as a fertiliser.

Employing specialised equipment for the first time in the UK, alongside a new slip form technique

As one of our main responsibilities, as principal contractor at Woodsmith Mine, we have been tasked with constructing the 120m-deep MTS shaft. This involves carrying out excavation of the vertical tunnel and creating reinforced concrete works. In order to ensure that we would ultimately deliver this key element of the project as efficiently, expediently and safely as possible, we performed our customary extensive research and preparation procedures in order to identify the most effective construction methodologies.

As a result of this thorough process, we decided to deploy a vertical shaft sinking machine (VSM), for the first time ever in the UK. Thanks to the building information modelling (BIM) techniques provided by fellow Carey Group company, Careys Design Team, our deployment of this state-of-the-art equipment has been hugely successful.

In addition to employing the VSM, we have also innovated and implemented a brand new slip form technique to construct the MTS shaft. By continuously pouring its concrete walls, simultaneously with the VSM’s excavation activity, we have been able to create the MTS shaft more safely, rapidly and cost-effectively.

Once again, one of the primary reasons that has enabled us to deploy this innovative new technique with such a high degree of safety and success can be traced to our use of 3D, 4D and virtual reality (VR) modelling. These models made it possible for us to forecast and account for a wide range of potential scenarios.

More details about Careys’ contributions to the North Yorkshire polyhalite project

There’ll be more stories coming about our work at Woodsmith Mine, so watch this space, where you can hear about our:

• Quick, safe and effective construction of the service and production foreshafts
• Thorough sustainability plan to protect the site’s precious national park surroundings
• In-depth health and safety approach, aimed at ensuring that each and every team member stay safe and enjoy a high-quality working environment