In September 2018, the SIEMAG TECBERG group received a major order from DMC Mining Service LTD., Great Britain,. The order was for the delivery of eight winders and sixteen platform winches, meant to be used in several shafts with depths of 1,600 m and 370 m at the new Woodsmith mine and the Lockwoods Beck pit in the North York Moors National Park in North-East England.
Polyhalite project in North Yorkshire
Sirius Minerals PLC is building one of the deepest underground mines in Great Britain. The Woodsmith mine is situated in the nature-conservancy area of the North York Moors National Park close to the north-east coast of England, about six kilometres south-west of Whitby. The underground potash and polyhalite deposit lies at a depth of about 1,500 metres and runs for several kilometres under the North Sea. During exploitation of the deposit stringent environmental requirements are to be satisfied. Amongst other things, the Woodsmith mine will be linked to the Teesside harbour by a 38-km-long tunnel with a special material transport system (MTS). After completion of the whole project, which is set for 2021, the annual output of fertiliser, which will bear the brand name POLY4, will be 13.4 million t. The service and production shafts and the two shafts for the MTS tunnel are important workings of the mine.
Order
The SIEMAG TECBERG group, Haiger, Germany, in September 2018 received from DMC Mining Service LTD (DMC), Great Britain, the order for four delivery packages that had been put out to tender. The order included the planning, manufacture and delivery of a total of eight winders and sixteen platform winches, including the associated automation and drive equipment, braking systems to the highest safety standards and superordinated control equipment for the hoisting equipment installed in and on the shaft.
Added-value thanks to international networking and expertise
The SIEMAG TECBERG group with its corporate network impressed both the client, DMC, and the end-customer, Sirius Minerals PLC (Sirius), Great Britain, with its group-wide collaboration with networked structures, interlinked production processes and production methods at its various locations, state-of-the-art technologies, safety-related features and presentation of reliable project schedules.
The deliveries will for the most part be made from the headquarters in Haiger, supplemented by deliveries and services from the subsidiaries WINDER CONTROLS Europe Ltd., Great Britain, and SIEMAG TECBERG Inc., USA. World-wide unique reference systems with winders, platform winches and braking systems, particularly for different mines, amongst others for the hoisting of polyhalite, for tunnel building projects such as the Gotthard Base tunnel, and regional service bases were further convincing arguments for a decision in favour of the company group. The client, DMC, finally decided to award the whole package to the SIEMAG TECBERG group, because performance of this technically and time-wise demanding project with the internationally experienced and independent system integrator of shaft and heavy-duty hoisting systems built by a single provider offered it the best prospects of success.
System integration and complete solutions by a single provider
In the meantime, the scope of delivery has been increased to include a further 53 rope sheaves and additional fittings for the automation equipment from the contractor. The first delivery lot of five winders, four platform winches and 33 rope sheaves will be delivered to the construction sites as early as the end of March 2019. The rest will be delivered at close intervals by the end of August 2019.
The shaft hoisting systems for the production and service shaft
The production and the service shaft, each having a diameter of approx. 6.75 m and a depth of 1,600 m, will for reasons of time be sunk in parallel. Both shafts will be dug with an SBR (shaft boring roadheader) by Herrenknecht AG. The SBR is fitted with a boom that can be pivoted through 360° and extended telescopically by up to 1.5 m and a cutting roller. During the cutting operation the SBR need not be traversed vertically over the entire cross-section of the shaft. Using this sinking technique, shafts have so far been sunk down to approx. 1,000 m. York Potash, at depths of approx. 1,600 m, is thus a showcase project that makes the highest demands of the shaft and heavy-duty hoisting systems.
Included in the scope of delivery is a total of eight platform winches (SBR winches). A BSR is moved along the shaft with four synchronously operated SBR winches. Each SBR winch can also be driven individually to even out the rope loads. To minimise the resultant maximum service load per SBR winch, the ropes will be triple sheaved. The approx. 367.5 t SBR will therefore be suspended in the shaft from a total of 12 rope lines. An individual SBR winch, however, has an intrinsic weight of approx. 67 t and can deliver a maximum rope pulling force of 525 kN. The wound-up rope package weighs a further 68 t or so and rope capacity is 5,000 m.
Used above the SBR is a moveable shaft working platform for shaft lining and installation of the shaft fittings. Two synchronously driven platform winches, so-called utility winches, each will be delivered for this. These will be installed straight onto shaft bearers above the two shafts. For transporting persons in the rope-guided kibble, hoisting of waste rock and material transport a kibble hoisting system (sinking hoist) will be delivered.
Shaft hoisting systems for the MTS shafts and tunnel
For environmental reasons the subterranean material transport system (MTS) will link the Woodsmith mine straight to the Teesside harbour in Middlesbrough. The tunnel will be driven parallel from three starting points, using a number of tunnel boring machines (TBMs) by Herrenknecht AG. One tunnel starting point will be located right by the Wilton portal near the harbour, and the two other starting points will be located in the so-called MTS shafts of the Woodsmith and Lockwood Beck mines. The two MTS shafts will be approx. 8 m in diameter and will lie at a depth of approx. 370 m.
The mine suppliers will supply all the winders, platform winches and rope sheaves that are needed to sink the MTS shafts and for the subsequent tunnel construction phase with waste and material hoisting. These include four platform winches, two double-drum winders, two single-rope drum heavy-duty hoisting systems and two single-rope drum winders, functioning as permanent auxiliary hoisting systems. During the sinking phase of an MTS shaft two synchronously driven platform winches are used to move a multi-stage shaft working platform. By means of the working platform the shafts will be sunk by a conventional boring and blasting method, the shaft lined at the same time and the permanent shaft fittings put in. Material transport and waste hoisting will be carried out with the double-drum winding machine during shaft sinking and tunnel lining. Rope hoisting to the shaft work platform and to the later tunnel floor will be carried out by means of single-way hoisting (auxiliary hoist). Tunnel driving with the TBMs will be carried out after shaft sinking. The TBMs will be finally assembled under ground. Shaft transport of the up to 67.5 t part-segments of the TBMs and material transport for later tunnel lining will be carried out with the TBM heavy-duty hoisting systems (TBM cage hoists).
Summary
The North Yorkshire polyhalite project is a momentous major private-sector project in European mining and will open up the world’s largest polyhalite deposit, which is located under a national park, through a 37-km-long access tunnel built for nature conservancy reasons. It is planned to bring up the POLY4 fertiliser at the Woodsmith mine from 2021 on.
The described requirements to be met by the winders, rope sheaves and complex superordinated electrical and automation systems to be delivered will make very stringent demands of the availability and reliability of the shaft hoisting systems for a total of four shafts during the different operational phases of shaft sinking and tunnel lining. To meet these very stringent demands, practically tested shaft and heavy-duty hoisting systems fitted with the SIEMAG TECBERG group’s own automation system will be used.
