Heavy lift and transport engineering specialist Sarens has installed a series of wind turbine components in challenging conditions at Kvitfjell Raudfjell, Norway.

The first team used an LG 1750 SX in SL22 configuration with 105 m boom and 250-tonne counterweight; an AC 220-5 auxiliary crane for tailing the wind turbine components; and an Explorer 5500 as a second auxiliary crane for relocating the main crane.

A second team used an LG 1550 in SL configuration with 98 m boom and 200-tonne counterweight; an AC 200 auxiliary crane for tailing the components; and an Explorer 5500 to reposition the main crane.

The third preassembly team used an AC 500-2 to assemble the first two tower sections, along with an Explorer 5500 auxiliary crane for tailing and relocating the 500-tonne crane.

Sarens' project manager Adam Kopaczewski, said: “In the beginning, there was only one main crane: the LG 1750. After three months, the client decided to order one more main crane team, and from November 2019 onwards we also had the LG 1550 and AC 200 as a second main team.”

Sarens said that the advantage of using the LG 1750 and LG 1550 cranes was that it did not need a superlift for assembling this type of wind turbine on a jobsite where it is difficult for crawler cranes to manoeuvre.

All cranes arrived at Tromso harbour and were delivered by truck to the project site some 40 km away. Assembling the cranes proved challenging – Sarens had to use a special container to support the main boom because the level difference between the main crane’s hardstand and the boom assembly area was sometimes as great as 10 m.

The Sarens crews lifted all of the wind turbine components including three tower sections, the nacelle, the generator, and full rotor. The largest load – the nacelle and generator – weighed 103.5 tonnes.

Aside from the terrain, weather was the biggest challenge the crew faced. From November through April, the worksite was covered in snow up to 7 m deep in some areas. Meanwhile, wind speeds sometimes reached almost 40 m per second.

Sarens performed the works on behalf of FairWind and Siemens Gamesa.