DISCOVER Magazine #7

Making the fleet

Published in category: Offshore Wind

Mette Jørvad, A2SEA


Mette Jørvad
Head of Communication and Marketing

Captain_Tamer_Masoud_Harbour_Master_Port_of_FujairahKeld Rasmussen
Head of Engineering

With an impressive amount of major contracts in the bag – Hornsea Project One, Horns Reef 3, Dudgeon and Arkona – offshore wind transport and installation company A2SEA can look to a stable future. Operating installation vessels capable of handling the biggest turbines has been a key part in securing that stability. A2SEA Head of Communication and Marketing Mette Jørvad and Head of Engineering Keld Rasmussen talk about how the company has kept in line with market demands.

A2SEA is undoubtedly a major player in offshore wind. The company has installed more than 40% of European turbines: a little over 1,400. Contributing to these figures are two installation vessels: the Sea Installer and the Sea Challenger. To keep up with the ever-increasing size of offshore wind turbines, A2SEA has implemented modifications to the cranes of both vessels. “We had sufficient lifting capacity, but we needed more reach,” explains Mr Rasmussen. “We needed to lengthen the crane boom so we could reach the height of the newest turbines.” When the time is right The Sea Installer’s design specifications included an 800-tonne crane. “However, we decided to upgrade the crane to give a 900-tonne capacity with a shorter boom and a 700-tonne capacity with a longer boom,” he continues. While the Sea Challenger’s crane upgrade was incorporated during construction, work on the Sea Installer was postponed: “We had plenty of work for the ship so we didn’t need it. We started to discuss it with Damen a couple of years ago. Of course we asked other shipyards to get an idea about pricing, but Damen was competitive.”

Full market coverage

Damen Shiprepair Amsterdam, part of Damen Shiprepair & Conversion, performed the crane upgrade: lengthening the main boom by inserting an extension. The crane has two modes: a long mode with the boom extension in place, and a short mode with the extension removed.

The work that they have done has been very fruitful – they really know what they are doing.

With the Sea Installer’s crane upgrade complete, A2SEA has strengthened its standing even further; a fact that reflected in a distinctly healthy order book. “We can handle all of the turbines that are on the market – including the Siemens 7MW and MHI Vestas 8MW,” comments Mr Rasmussen. Furthermore, because Damen’s scope of work included structural reinforcements as well as lengthening, the Sea Installer can now sail in heavier weather (4.5-metre waves instead of 3.5 metres) during port transits; providing a significantly larger weather window.

Once more the ground breaker

The Sea Installer’s first major job after her upgrade? At the time of writing, she was preparing for work at the Burbo Bank Extension wind farm. “These turbines – 8MW MHI Vestas – are the biggest on the market,” notes Ms Jørvad. “This will be the first time that turbines this size have been installed, making it a pioneering project.” This is not the first time that the Sea Installer has performed first-of-kind installations. “Straight after delivery, she installed 6MW turbines at Gunfleet Sands Extension. Back then, these were also the biggest. We are very proud that she is doing a first again.” The offshore wind industry is relatively young – and it is developing fast. A2SEA is ready for any changes that the future brings. “There has been lots of talk about 10MW turbines. But, as far as we can see, there is no plan as to when this will happen,” Ms Jørvad goes on to say.

Our fleet is up to date for at least the next five years; giving us time to plan new vessels for the bigger turbines whenever they appear.

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