Severn Trent Water turns to Archimedes

Wolverhampton, UK - Severn Trent Water has awarded Deritend a contract to supply and install four of the largest Archimedes screw type pumps in the UK. The order, through Norwest Holst, covers four off 34 tonne Archimedes type screws for a new storm water management scheme at Green Lane in Derby.

Working with Landustrie, who are manufacturing the screws, Deritend is supplying the motors, gearboxes and installation work for the project which is expected to be completed during the first quarter of 2009.

To help combat heightened flood risk Severn Trent Water has pledged to spend £40 million across the Midlands on flood defences. Some of this will be spent on sewage treatment works such as the Green Lane project enabling them to better handle large volumes of flood water that can arrive in a matter of hours.

The concept of the Archimedes pump has been used for several thousand years, reputedly used to irrigate Nebuchadnezzar’s hanging gardens of Babylon. In this instance they are being used to direct wastewater overflow into a new screening plant to help prevent the contamination of local water resources. This extremely simple pump system is still the most efficient way of transferring large volumes of water over short distances.

The four Landustrie screws will measure 15 meters long with a diameter of 2.5 meters and are completely self contained. Each screw is capable of transferring 2,000 litres per second. When in place the screws would operate simultaneously being capable of transferring over 8,000 litres per second. Landustrie are the world-wide market leader in screw pump technology, and have over a hundred years experience in designing and manufacturing this type of screw pumps in whatever size. The units will each be driven by an 185kW WEG motors and Flender gearboxes.

“After winning another new framework contract with Severn Trent Water we knew that we would receive some challenging jobs," said Jamie Wesley, engineering contract manager for Deritend Site Services. "A project of this size wouldn’t be possible for many companies, we are lucky that we can draw on our vast experience in supply, installation and maintenance to provide a complete package to the customer.”