Fibex Composites has supplied its Trenchlite® GRP cable trough products to a pioneering polyhalite mine in North Yorkshire where the ease of installation and speed of delivery were key factors in the construction phase.

Sirius Minerals' new polyhalite project represents the largest private sector investment in North East England and will contribute an estimated £2.3 billion to the UK economy. The Woodsmith mine, located near Whitby, is within the North York Moors National Park and as a result, managing the impact of the site is crucial. A key part of this was minimising the number of vehicles needed to move materials to the site.

With hundreds of metres of cabling required to provide power to the various areas of the large site during construction, Sirius Minerals needed a cable management system that would meet a specific set of requirements.

Steven Bowes, Project Manager - High Voltage at Sirius Minerals explained: "We needed a product that was lightweight and easy to transport due to the limits on the number of deliveries to the site. The troughs and covers also needed to be vehicle rated as the cables had to be routed across access routes. Additionally, as the layout of the site will change considerably as mining commences the system needed to be easy to remove and relocate."


Following a review of the available options, Fibex's Trenchlite® GRP cable trough was chosen. Fibex supplied a range of standard straight, tee and right-angle troughs in both 300 mm and 600 mm depths as well as specially fabricated bespoke large radius bends suitable for HV cables. Alongside the Trenchlite® troughs, which are tested to BS EN 1433 classification for vehicular and pedestrian areas, Fibex also supplied its GRP Heavy Duty Trench Covers, which comply with BS EN 124 Class B125 (capable of withstanding 125kN Test Load).

Trenchlite® GRP troughs provide a 95% weight saving compared with the equivalent precast concrete product. A full vehicle load of 26 precast concrete troughs weighs around 21 tonnes. In contrast, 104 Trenchlite® troughs, weighing just 3.5 tonnes, can be loaded onto each vehicle – delivering a 70% reduction in transport.

The lower weight also makes installation safer and easier. Weighing just 31kg, each Trenchlite® section can be manually moved into place by two people without the need for lifting equipment or additional safety measures.

Steven continued: "We are delighted with the quality of the Trenchlite products, which met all our requirements for speed and ease of installation on site. The Fibex team really made the process easy and we have received excellent service and support from them. We supplied the details of what we needed and they developed the solution, including custom sections that were simple to fit."

During the construction of the mine, Sirius has committed to investing £130 million in local projects that will protect and improve the countryside within the National Park. This includes planting more than 7,000 hectares of trees that will off-set the carbon emissions and create new habitats for wildlife. The company has also agreed to rigorous environmental limits on noise, pollution and traffic throughout the life of the mine. This includes the construction of a 37km long tunnel to move the polyhalite between the mine and the processing facility.

Ashley Jones, Director at Fibex concluded: "We are proud to be a part of delivering this truly pioneering and flagship project, demonstrating the ingenuity of UK construction and industry."

The construction of the Woodsmith mine began in May 2017 and the mineshafts are expected to reach the polyhalite seam in late 2021.

To find out more about the Fibex range of GRP Composite products and solutions visit www.fibexcomposites.com.