Sarens has installed 89 monopiles at the Fryslân wind farm located on Lake IJssel in the Netherlands.

The Belgium-headquartered heavy lift specialist said that the shallow waters of the lake and the restricted access via narrow locks called for a unique installation solution.

Sarens’ engineering and operations team devised a plan that involved combining modular barges from its fleet and its twin barge Josef-Rosa to create what it called the Sarens Soccer Pitch – a barge area that spanned more than half a football field.

The barges were prepared and assembled – as much as possible – in Ghent, Belgium, and transported to the mobilisation location in Lelystad. Here, a Demag CC2800 was used to install 42 m-long MB2500 beams on top of the barges to spread the load of the 1,250-tonne capacity PC6800 crane, which was deployed for the operation.

The Sarens Soccer Pitch was equipped with four legs that were pushed into the seabed for stability.

With the barge solution in place, Sarens began installing the monopiles in September 2020. The monopoles, which had a maximum weight of 250 tonnes and measured 39 m long, were delivered directly from the manufacturing yard in Rostock, Germany.

Mart Van Hoorn, Sarens project manager, said: ““In spring 2021, Sarens will start wind turbine generator installation with the same barges and same crane equipped with a longer boom.”