Heavy lift specialist Sarens is heavily involved in the load-in, load-out, transport, and storage of several monopiles and transition pieces for the Saint-Nazaire offshore wind farm project in France. The work is being performed at the port of La Rochelle in France.

As part of its agreement with DEME Offshore, Sarens was hired to offload and transport monopiles and transition pieces weighing a maximum of 980 tons and measuring 62 metres long. During load in, Sarens is transporting four monopiles and transition pieces in two days. During load out, Sarens is transporting and load in three monopiles and three transition pieces in two days. A total of two operators and dockers are involved in the operation.

The vessel cranes are unloading the transition pieces on temporary supports at the quayside before being taken by the Sarens TP Handler. The use of the TP Handler is a new concept with several advantages, including increased safety because all preparation is done at ground level. It was certified with a load test in Wolvertem and sent by road from Belgium to France, with delivery just in time to limit its presence on site. The TP handler was then assembled within one week.

The vessel cranes are also unloading some monopiles directly onto SPMTs equipped with saddles, while others are placed in quayside storage areas organised by Sarens. To that end, Sarens and a local subcontractor have constructed 16-18 dunes, ranging in height from 2,1-2,6 metres, for monopile storage. Sarens has also organised the on-site steel support for 48 transition pieces. 20 load-ins were done during 2021 and 20 out of the 29 load-outs are already completed.

SAL Heavy Lift, part of the Jumbo-SAL-Alliance, transported a total of 80 monopiles and 80 transition pieces spread over a total of 20 trips. First of the journey’s was completed in February with the final delivery completed in early October last year.

The 480 MW Saint-Nazaire offshore wind project is being developed by EDF Renouvelables and EIH S.à r.l, an indirect subsidiary of Enbridge, and CPP Investments. Saint-Nazaire, scheduled to be operational in 2022, is the first commercial offshore wind farm installed in French waters, situated on the bench of Guérande, approximately 12 km from the coastline. The offshore wind farm will feature 80 Siemens 7 MW turbines, installed at depths between 12 and 25 metres. Monopiles and transition pieces have been manufactured by Sif Group.

In August 2021, Heavy lift specialist DEME installed the first offshore substation (OSS), weighing 2,100 tons, at the Saint-Nazaire offshore wind farm. The electrical substation was constructed by a consortium including Atlantique Offshore Energy, the business unit of Chantiers de l’Atlantique dedicated to Renewable Marine Energies, GE Grid Solutions and DEME Group’s French subsidiary SDI.