Letter of intend to equip semi-submersible crane vessel

Unlike traditional tub cranes, which make use of either bogies or large wheels for their slew system, the Huisman cranes will employ large bearings of the company’s own design. This technique, the Netherlands-headquartered company noted, represents a step change in the crane industry, and was previously successfully used on the 5,000-tonne offshore mast crane for the pipe-lay crane vessel Seven Borealis and the 4,000-tonne offshore mast crane for Heerema’s deepwater construction vessel Aegir. The use of bearings on the new 10,000-tonne Heerema cranes instead of the traditional slew systems allows for very accurate control of the slewing motion of the crane and requires very little maintenance. Another large benefit of using a bearing is said to be a significant weight saving. The slew bearings of these cranes will have a diameter of 30m.
The cranes further feature a 2,500-tonne aux hoist and a whip hoist with a maximum outreach of 155m.