When construction solutions business, Tarmac, contacted Selwood to assist with dewatering a new sinking at their Swinden Quarry in North Yorkshire, Selwood’s experts were quick to find the right solution.

Having purchased a Selwood HM250 several years ago, which has been successfully dealing with the water containing abrasive lime at this site, Tarmac approached Selwood for a second pump for their next two sinkings.

The existing HM250 remained in place, continuing to provide its original function, and the additional pump was required to move ground water from the sinkings to the main sump – where the HM250 was located.

Selwood’s expert team looked closely at Tarmac’s requirements and recommended a smaller, more effective solution, cutting power usage by 200kW.

Making a site visit, Selwood assessed Tarmac’s needs in depth, evaluating them against the efficiencies of Selwood’s pump portfolio.

Selwood’s team suggested installing the newly designed H200 – a 132kW high head pump, smaller than the HM250 – to feed into the main sump. By building the pump to Tarmac’s custom specifications, including setting the system curves of the pipework and upping the power (equating to a 95kW electric motor), the H200 could be used in conjunction with the existing site dewatering system.

Using a variable drive has enabled Tarmac to achieve 1100rpm at the first sinking (115m bench) and will enable 1250rpm to be achieved at the second sinking (95m bench), controlling the power to meet the duty required in each situation. The duty could not exceed 500m3 an hour on this pump as it had to be balanced with the duty of the HM250 pump. By custom-building the new pump, the system has achieved balance and efficient operation at the 115m sinking, eliminating any overflow.

Tarmac is pleased with the results. Tony Crooks, project manager for Tarmac said “Our experience of operating the existing HM250 gave us confidence in the Selwood products and support team. We were impressed with the detailed assessment of our requirements and the following bespoke recommendations which have resulted in an efficient e a custom-built pump for the job.”

For more information about purchasing a pump from Selwood, visit our Pump Sales pages.