Big BMS crawler assembles Danish offshore wind farm

Lifting specialist BMS Heavy Cranes is using a Liebherr LR 11350 crawler crane to assemble 106 wind turbine towers in Esbjerg, Denmark.

These towers, each more than 100 metres tall, are part of a major project for a new offshore wind power park near Borkum.

The operation began in December 2023 and finishes by the end of 2024.

Esbjerg is the centre of Danish offshore wind power activities in the North Sea.

BMS is using the 1,350 tonne capacity Liebherr lattice boom crawler crane to assemble tower elements into a tower reaching 110 metres high. The fully wired tower is erected on a special platform by the crane and is then lifted on board by the erection vessel’s on-board crane.

Four wind power plants (12 rotor blades, four turbines and four towers) are taken on each trip.

“We are safe up to a wind speed of 13.5 metres per second,” said Lars Thomsen, onsite project manager at BMS Heavy Cranes.

In addition to Liebherr’s LICCON system, which monitors the wind, BMS also uses its own app, which allows those responsible to access the wind data at any time.

“This is very important,” says crane supervisor Michael Leonard, who normally co-ordinates installations for BMS in Scotland. “I keep a close eye on the wind and weather and also co-ordinate with the installation company Fairwind and the wind turbine manufacturer – we only do the lift when we say together that it will be pulled. A tower element weighing 100 tonnes must under all circumstances not be allowed to start swinging.”

Complex lifts

The Liebherr crawler cranes in the 1,400 tonne capacity class used by BMS are continuously upgraded and ballasted with 400 tonnes on the superstructure. For heavy lifts, an additional 260 tonnes of suspended ballast is added.

BMS crane supervisor Michael Leonard checking the windspeed with BMS Mobil-App. (Photo: Liebherr)

Michael Leonard added, “I know all of our Liebherr cranes because I operated them. I interpret every sound during operation and am in constant radio contact with our operators. BMS drivers check the four large LR crawler cranes daily before commissioning – fixed teams of drivers are assigned to the machines – work is carried out in two shifts of 12 hours each.

“Even fog, rain or darkness do not hinder the work. Cameras on the hook and at the tip of the boom give the driver a perfect view of the hook, ropes and load. Other cameras monitor the winding and unwinding of the ropes, as is usual with large LR cranes.”

Additional ballast carried by transporter for heavy lifts. (Photo: Liebherr)