FLEXIBLE SEAFASTENING AND LIFTING ARRANGEMENTS

With several thousand kilometres of coastline along the North Sea, the English Channel, the Atlantic Ocean and the Mediterranean Sea, the French market is one of the world’s most important growth markets for energy production from offshore wind. SAL has provided logistics support to specialist offshore contractor DEME Offshore for years now. This is why SAL’s MV Svenja handled the complex transport of the heavy foundations for the construction of one of France’s first four offshore wind farms: the Saint-Nazaire Offshore Wind Farm.

Following the Hornsea 2 project, which included the transportation of monopiles, MV Svenja was immediately mobilised for her next project at the port of Eemshaven: the Saint-Nazaire offshore wind farm foundation transport. The Saint-Nazaire wind farm is an important milestone for the French energy transition – a key stepping-stone on the country’s path to a carbon-neutral future.

“We have quite an impressive track record of projects carried out together with DEME Offshore,” explained Morten Hinrichs, Project Manager at SAL Heavy Lift. “ This is one of the reasons that DEME hired us to participate in this project. In addition, one main criterion was the ability to transport four monopiles (MPs) and four transition pieces (TPs) per shipment. After a detailed feasibility study, we found that our Type 183 vessel MV Svenja could handle the job. Another benefit: The vessel’s speed also provided DEME the greatest possible flexibility,” he continued.

In total, the project scope involved transporting 80 monopiles (weighing up to 979 tons and measuring up to 62 metres) and 80 transition pieces (weighing up to 496 Mt). The Type 183 vessel MV Svenja made 20 journeys from Rotterdam, the Netherlands to La Rochelle, France.

Matthieu Moerman, Head of Marine Projects at SAL Heavy Lift, emphasised: “Finding the ideal transportation solution was very exciting. The set limits in terms of weight and dimensions of the foundations were complex and proved challenging in the planning phase. In the end, we provided a detailed and comprehensive transportation solution and documentation which fully covered our client’s high demands.”

The team designed a detailed lifting process with a step-by-step analysis of the complete lifting path and a tailor-made bumper and guide system for the relatively tall transition pieces measuring over 30 metres in height. All transition pieces are being loaded without using MV Svenja’s stability pontoon.

“The combined transport of monopiles and transition pieces, especially the transport of transition pieces on the engine deck, made it necessary to re-evaluate the sea fastening requirements for the cargo. We carried out sea fastening calculations based on the set weather limits and the transport in open-hatch condition. In the end, we used our well-known and already established sea fastening grillages for this type of transport to secure the monopiles and transition pieces. We modified them in line with the new dimensions of the foundation,” explained Matthias Meyer, Senior Project Engineer at SAL Engineering.

MV Svenja started the first of her 20 journeys in February 2021 and completed the project in October 2021. At SAL, we are very proud to have set foot in the offshore wind business over the past few years – and are committed to working towards a cleaner, greener future.

“What do we like about SAL? They have a solid team set-up at SAL, a proven transport solution, and are extremely agile when working with us to develop solutions for our needs.” – Pieter de Jonghe, T & I Manager, DEME Offshore FR

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