Load-Out of 71 Gravity Base Structures by Sarens in Le Havre – Video
Sarens was commissioned by the BSB consortium (Bouygues Travaux Publics, Saipem and Boskalis) to work in the port of Le Havre on the lifting, transport onshore and load-out operations of 71 gravity based structures (GBS) of approximately 4,800t each, serving as foundations for wind turbine generators, from their manufacturing site in Le Havre onto cargo transportation barges.
The Fecamp offshore windfarm, located approximately between 13 and 22 km off the Normandy coast, will generate enough energy to provide sustainable electricity for more than 770,000 inhabitants.
Sarens, world leader in heavy lifting, engineered transport and crane rental, is playing a direct role in the construction of the wind farm by lifting, transporting onshore and loading-out onto transportation barges the 71 gravity based structures (GBS) serving as foundations for the wind turbines. Each base weighs approximately 4800t, with a diameter of 31m at the base and a height between 48m and 54m.
To lift each of the GBS, a Gantry system is specifically created for this work, consisting of two different units which are moved around site on SPMT axle lines. After being positioned around each GBS, the load is secured by four lugs, and the two parts of the gantry system are interconnected by data cables so that they can operate as one. After lifting the GBS, it is positioned on 180 axle lines of SPMT for transport to the Cargo Barges at the quay side
To ensure the success of the operation, Sarens has installed on each of the three Cargo barges a sounding system capable of measuring the amount of water in the ballast tank, and a series of interconnected pumps for de-ballasting to be used during loading operations. It took more than 120 trucks and nearly three months of transport to the port of Le Havre for the Sarens technical team to have all the equipment necessary to carry out the entire operation.
To ensure that the marine spread used for the installation offshore of the GBSs does not suffer downtime, Sarens will conduct a 24-hour loading process for the barges. Three foundation bases are loaded on each barge, in a continuous operation of maximum 38 hours per barge. This process must be repeated 24 times, which will require the participation of a large number of highly specialized personnel, not only for the loading manoeuvre itself, but also for all the operations related to the handling of the winches, the preparation of the gantry system in each operation or the reconfiguration of the SPMTs prior to the arrival and loading of each barge.
Sarens owns extensive international experience in the assembly and maintenance of wind farms. It is participating in installations in France such as Saint Nazaire, Provence Grand Large or more recently, in the lifting and transport work for the foundation bases of the new offshore wind farm in Saint Brieuc, off the Brittany coast, where it has been able to transport loads of more than 1,150t.