HELWIN alpha platform installed
23.08.2013 News Archive
Helwin alpha platform installed
OVERDICK is proud to announce the successful installation of the latest of our line of self-installing platforms. The HVDC hub HelWin Alpha is the seventh of platforms designed following OVERDICK’s MOAB® concept.
The HelWin Alpha topsides has been designed with a watertight hull which allows it to be fabricated in a drydock and wet towed to the site without the need of a transport barge. The platform has been positioned over the foundation piles and after stabbing the legs on the piles though the LMUs the platform was elevated to its design clearance of 22 meters above sea level by means of a temporary hydraulic jacking system. With its record setting topsides weight of over 12,000 tonnes the structure is beyond the lifting capabilities of offshore cranes. The capacity of the jacking system was scaled to meet the lifting safety and operational requirements and thus allowed installation of the complete topsides in one operation, eliminating the need for multiple expensive offshore lifts and minimizing the requirements for offshore hook-up and commissioning. The platform was mechanically completed and pre-commissioned at the yard.
The platform stands in 23 meters of water about 16 nautical miles North-North-West of the island of Helgoland in the German Bight of the North-Sea. Here it will provide the tie-in to the electric power grid for the offshore wind parks Nordsee-Ost and Meerwind by transmitting 576 Megawatts of clean energy.
With three more HVDC hubs of even greater dimensions at various stages of design, fabrication and installation on the way, the Overdick MOAB® concept marks the way forward for effective realization of heavy weight topsides as required by the offshore wind industry.