April 24 - Netherlands headquartered specialist in lifting, drilling and subsea solutions, Huisman, has revealed a new patented type of active heave compensated (AHC) crane: the Rope Luffing Knuckle Boom Crane.

These cranes combine the benefits of a normal rope luffing crane and a traditional knuckle boom crane, so that the machine offers a high lifting height and a large capacity at outreach.

The capacities of the new cranes range from 400 up to 1,200 tonnes at up to 5,000 m water depth, and the first crane of this type - a 900-tonne capacity Rope Luffing Knuckle Boom Crane for Subsea 7's Seven Arctic - is scheduled for delivery in 2016.

In addition to the cranes' high lifting capacity and large lifting radius, the boom of the crane can be stored vertically saving valuable deck space.

The main hoisting system comprises a traction and storage winch system and a separate heave compensation system, which means that both lifting/lowering and heave compensation can occur simultaneously with no performance interdependency, resulting in a better overall system performance and increased safety.

Because the crane is fully electrically driven, the power consumption, noise levels, and the number of components are reduced, said Huisman.