Overdick

The HelWin alpha topsides is designed with a watertight hull allowing it to be fabricated at a shipyard and wet towed to the field without a transport barge.

The platform has been positioned over the pre-installed foundation. After positioning the legs have been stabbed on the piles through a set of LMUs. Subsequently, the platform has been jacked up to target elevation of 22m above the sea by means of a temporary, hired, jacking system.

With its record setting topsides weight (mechanically completed and precommisioned) of over 12,000 tonnes and the bulky dimensions, the platform is beyond the lifting capabilities of any offshore crane available.
The capacity of the jacking system was scaled to meet the lifting 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.

This is the first of a series of 4 HVDC large platforms to be installed which have been designed by OVERDICK.