Sarens, a company specialising in crane rental services, heavy lifting and engineered transport, successfully carried out the Sofia OCP Jacket and Topside Weighing and Loadout project. The firm provided a complete package of services, including manpower, engineering, mooring winches, weighing equipment, and 524 axles with 18 PPU Self-Propelled Modular Transporters (SPMTs) for the weighing and loadout. This work was carried out in collaboration with RWE & GE and managed by Seatrium, taking place at Seatrium's shipyard in Batam, Indonesia from 25th May 2024 to 15th June 2024.
The Sofia Offshore Wind Farm has a power generation capacity of 1.4 GW and is located on Dogger Bank in the North Sea, 195 kilometres off the coast of the UK. Its 100 turbines are mounted on monopiles, reaching a height of 252 metres.
The project involved the offshore converter platform (OCP), a crucial element for the HVDC electrical system of the offshore wind farm. This tool is responsible for converting the energy into direct current (DC) and then transmitting it to land. Thanks to this system, the electricity generated by the rotation of the wind turbines is converted from 66kV alternating current to 320kV direct current. Two 7-kilometer-long cables carry the electricity to the Lazenby converter station.
The main part of the project consisted of transporting and loading the gigantic OCP topside, which weighs 14,000 tons and is 57 metres high, as well as the OCP Jacket, weighing 5,250 tons and 51 metres high. This complex job marks the heaviest topside move in Southeast Asia, and historically, one of the heaviest ever undertaken in the world.
Although the weight and size of the parts posed a major challenge, Sarens' expert logistics team ensured punctual delivery and maintenance of the OCP units. To make this possible, Sarens provided a complete package of services, including manpower, engineering, mooring winches, weighing equipment, and 524 axles with 18 PPU Self-Propelled Modular Transporters (SPMTs) for the weighing and loadout. At the peak of the work there were 28 Sarens members, who had to deal with adverse conditions, including the impact of the rainy season on site preparation.
The wind Sofia offshore plant will be commissioned in 2026, at which time it will begin generating clean energy that will reach hundreds of thousands of homes in the United Kingdom by making use of a network of approximately 360 kilometres of inter-array cables from the turbines to the platform.
Sarens has extensive international experience in the assembly and maintenance of wind farms. It has participated in various installations around the world and particularly in Europe, as in France (Saint Nazaire and Saint Brieuc) and the UK, where its last project is now successfully completed. Recently, Sarens has worked in the marshaling of 62 the monopiles, each weighing 2000 tons, the largest and heaviest XXL monopiles ever to be handled in the UK, and now the 882 MW Moray West offshore wind farm, is well on it's way to contribute to the Scottish renewable energy network.
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