Pump hire specialist, Sykes Pumps, has supplied and installed a total of 25 pumps to provide a site de-watering solution for the construction of a major new water supply mains in Cumbria.
The Thirlmere Main project involves construction of a twin 30km pipeline between Thirlmere Reservoir and a new water treatment works near Redmain. The route has been designed to make the most of gravity and the natural topography of the location to enable unaided flow, however, several points along the route involve tunnelling under rivers and road crossings. It’s at one of these locations, at Bassenthwaite near Keswick, that contractor, Roadbridge, required a pumping solution to de-water the site and enable excavations.
Explains Jonathan King of Sykes Pumps: “Roadbridge contacted us with the idea of creating wells along the route of their excavation where we could locate pumps to de-water below the excavation depth. It was an unusual proposal but the proximity of natural water courses and seasonal rain levels in Cumbria meant that de-watering the area was a significant challenge.
“Our role was to develop the client’s idea into a viable solution and install the equipment to provide reliable de-watering infrastructure that could be managed by the client’s team on site.”
The Roadbridge team dug six wells, each to a depth of 6m and Sykes Pumps supplied and a total of six P701 electrical submersible drainage pumps; one for each well. These compact 2” submersible pumps provide a flow rate of up to 11 litres/second at a maximum head of 16m and offer a robust solution for constant, long term use. In a particularly wet, marshy part of the work site, Sykes Pumps also installed an additional nine 3” SP30 submersible pumps to ensure the area was sufficiently dewatered to install the pipe.
Each pump fed into a 350m 6” main discharge line and was fitted with a non-return valve, which then led to one of two Sykes Silt-Aways on site to enable the pumped water to be cleaned if required before being discharged into the nearby watercourse. As part of the setup Sykes Pumps also provided two generators, each with their own fuel cube, to ensure the electric submersible pumps could run on a 24/7 basis.
In conjunction with the electric submersibles, Sykes Pumps also supplied six GP100 and four GP150 Super Wispaset diesel pumps that could be used on the opposite side of the excavation area to that of the submersibles.
Jonathan King continues: “In this area of the site, the power connections to electrical submersible pumps would have needed to run across the dig area, so, for safety reasons, we opted for diesel pumps here. These were supplied as bunded pumps to avoid any risk of fuel spillage and we provided toolbox talks for the client’s site teams to ensure that operatives were familiar with safe and efficient operating requirements for all the equipment installed.”
Following installation of the equipment, Sykes Pumps provided fortnightly servicing and maintenance visits as part of a turnkey offer, which also included a call out service with a 4-hour maximum response time. The de-watering solution was also designed to provide flexibility for Roadbridge as equipment could be moved to new locations as worked progressed.