With the advent of a new generation of increased capacity semi-submersible crane vessels (SSCVs) in the 1980s (the DB102 and the M7000), new concepts in twin-crane lift installed jackets and integrated decks began to emerge. During the late 1980s projects such as Veslefrikk, Gyda and Kittiwake took advantage of the increased lift capacity available. Whilst each of these projects broke lift records, the SSCV lift capacities were not fully utilised. However, in the early 1990s lifting at the limit has really come of age.
This paper critically examines the close correlation between installation vessels and the trend towards larger and heavier lifts, especially for integrated decks. The limitations of the SSCVs are reviewed, and the basic methods of "tailoring" jacket and deck design to maximise the SSCV lift capacities are identified. These methods are then reviewed and questions raised for the future.