Hundreds of Tsurumi pumps used in biggest Swedish power project for 30 years

A staggering 650 Tsurumi pumps are working on one of Sweden’s biggest power grid and infrastructure projects in the last 30 years, keeping the ground dry and safe along a 250km route, while new high voltage power cables are laid underground.

The South-West link project, which began operations in 2012, includes the construction of underground transmission lines to connect Nässjö’s power grid in Sweden to Norway’s stem power grid in Oslo.

The EUR 807 million project spans across almost 250km from Barkeryd substation – near Nässjö – to Hurva in Sweden, following old power lines through remote villages and forests. It’s this section of transmission cable that is being placed underground, and then continues alongside Sweden’s main highway – the E6. Because of the landscape and large rainfall in the region, some areas are prone to floods and have a high water-retention rate.

“Svenska Kraftnät & Skanska have to work around these challenging conditions,” said Magnus Malmerin, Manager at Tsurumi-Intec Sweden. “Some water is visible and very close to the surface but even if the ground appears dry, lots of water is trapped underneath. When you start digging, water floods the area, causing a potential safety hazard. Safety precautions are crucial because the transmission cable will eventually be carrying about 1,400 MW of electricity.”

Pipes are placed in the ground every 30-50 meters along the cable trench and Tsurumi pumps are placed inside the pipes to lower the water table before cables are installed. Additional pumps are also placed directly in the trench where required. They can be placed anywhere along the stretch because the pumps are hooked up to a number of moveable generators.

There are three different models of Tsurumi pumps being used at the project, including the LB800, KTV2-22 and KTV3-37. The LB800 can pump 310 litres of water a minute and is a compact light-weight pump, easily transported from one area to the next.

The project is being implemented by Swedish Transmission Network Operator (TSO), Svenska Kraftnät, and its Norwegian counterpart Statnett. To combat the high water levels and occasional swamp-like conditions, the 650 Tsurumi pumps have been supplied by Skanska Maskin AB – the rental division of the Skanska Corporation in Sweden.