The new TCC 78000 heavy-duty gantry crane from Liebherr-MCCtec Rostock GmbH loaded 72 foundation piles for Denmark’s largest wind farm “Kriegers Flak” between May and September 2020.
This was the first external loading for the Liebherr TCC 78000 heavy-duty gantry crane, commissioned by EEW Special Pipe Constructions GmbH in
cooperation with Vattenfall. The crane offers a maximum lifting capacity of 1,600 tonnes and is used at Liebherr for internal logistics processes in the production, assembly and dispatch of maritime cranes.
Due to the flexible operating periods of the TCC 78000, the 72 monopiles were loaded using the new rail-mounted gantry crane. Delivery of the monopiles to the construction site had to be carried out just in time. This meant that the assembly cycle of the installation ship ‘Svanen’ on the high seas set the pace for the loading in Rostock.
“We are pleased about the successful completion of the loading activities of the monopiles for the Baltic Sea wind farm Danish Kriegers Flak. In Liebherr we have a strong and reliable partner at our side and are convinced that we will continue to move great things together in the Rostock seaport in the future,” says Heiko Mützelburg, Managing Director of EEW Special Pipe Constructions GmbH.
Loading the monopiles was not an everyday job even for the experienced heavy lift team of the TCC 78000. This was because the pipes were loaded directly into the water at berth 152 in Rostock’s overseas port and then towed by two tugs to the wind farm construction site. The floatability required for this was produced on a specially provided 7,640m2 area, the so called Plug Installation Area (PIA), on the Liebherr site. The two open sides of the tube are sealed with specially manufactured sealing caps, so-called plugs.
The company Van Oord Offshore Wind Germany GmbH carried out the plug installation. Van Oord is also responsible for the construction of the wind farm on the site. Afterwards, the sealed, now floatable monopiles were transported to the berth and loaded into the water with the TCC 78000 over the quay wall. The slinging of the load on the TCC 78000 was carried out with the professional support of Liebherr employees, in the form of instructors and crane drivers under the supervision of the Liebherr Lifting Supervisor.
The slightly conical monopile construction and the centre of gravity shifted in the longitudinal direction by the plug weights require exact planning as well as a precise sense of proportion and a lot experience of the team. Despite the highest safety precautions, it sometimes takes only 60 minutes from the moment the monopile is attached until the load weighing hundreds of tonnes floats in the water. Afterwards, a deep-sea tug pulls the floating monopiles about 70 nautical miles in the direction of “Kriegers Flak”. In total, two sea tugs were in constant rotation.
