OLKO-Maschinentechnik GmbH has been awarded a contract by Sirius Minerals for the supply and commissioning of two winders for its North Yorkshire Woodsmith polyhalite mine. The project area contains the largest, highest grade resource of polyhalite to be found anywhere in the world. The polyhalite resource of 2.66 billion tonnes, as defined according to the internationally recognised JORC code, represents 7% of the project’s area of interest. Polyhalite will be extracted via two mine shafts and transported outside of the National Park to Teesside on a conveyor belt system in an underground tunnel of approximately 37 km of length. It will then be granulated at a materials handling facility, with the majority being exported to overseas markets. Sirius Minerals is aiming to achieve first product from the mine by the end of 2021, ramping up to an initial production capacity of 10 Mt/y and then full production of 20 Mt/y.
In the first stage of the project, OLKO is to supply two winders of double-drum Blair type, one for the service shaft and one for the production shaft at Woodsmith mine. Shaft depths are approximately 1,594 m (production shaft) and 1,565 m (service shaft). As OLKO was involved relatively early in the project phase, the winders have been designed that they will be used for shaft sinking purposes as well as for permanent hoisting after the shafts have been built. The winders are amongst the largest in the world: the diameter of the drum including disc brake is 6.8 m, while the motor power of the production shaft winder amounts to 9.3 MW. Hoisting speed during permanent hoisting of the production shaft winder is 18 m/s. The 35 t capacity skips will be loaded at the 1,520 m level, while the unloading facility is installed at the 360 level, where polyhalite will be transferred to the mineral transport system’s tunnel conveyor. The winder is equipped with slide bearings and the most modern mutli-channel braking system, type COBRA01, a joint development of OLKO and Siemens.
Most of the components are presently manufactured and being packed for transportation to site. The design, manufacturing and handling of logistics issues of such large winders are not without challenges, for the mechanical components as well for the electrical portion, which will be supplied by Siemens. However, with completion of design and manufacturing, which has been performed in close co-operation with the project team of Sirius Minerals, huge progress has been achieved so far. Workshop tests of several components have also been completed successfully under the supervision of external experts. The next phase is the logistics part, including the transportation of all components to site, some of which weigh more than 70 t. OLKO says it considers the execution of such a flagship project as one of the biggest in the history of the company and is delighted that their hoists are part of one of the world’s largest mining projects.
