ABSTRACT
ABSTRACT: The paper describes concept and general design of a reinforced concrete vessel which has been developed for heavy offshore lifting operations. The vessel has overall dimensions of about 110 m × 87 m × 55 m and is able to lift up to 25 000 tonnes. It is currently under construction in Rotterdam and will be commissioned in the first quarter of 2009. Its key features are pivoting lifting frames and large flushing tanks that enable to lift entire topsides or jackets. Draft is controlled in a large scale by ballasting compartments of the concrete hull. For its propulsion, the vessel has 8 thrusters which are mostly required for positioning during lifting. For transportation the vessel will be towed by tug boats. Operations are controlled by a permanent crew that is accommodated and supplied by a living quarter with helicopter deck.
