FibreTrac crane adds strength, flexibility

Sept. 25, 2019
MacGregor says that its dedicated fiber-rope offshore crane, FibreTrac, allows operators to use the full lifting capacity of the crane, at practically any depth, so that a smaller crane and vessel can be used for more assignments.

MacGregor says that its dedicated fiber-rope offshore crane, FibreTrac, allows operators to use the full lifting capacity of the crane, at practically any depth, so that a smaller crane and vessel can be used for more assignments, and owners are able to bid on a wider range of contracts.

The company says that this is made possible because of neutrally buoyant, high performance fiber rope. The rope weighs virtually nothing in water, so regardless of the length of rope used, it does not add anything to the load experienced by the crane, according to MacGregor. This is in complete contrast to steel wire cranes, which have to bear the load as well as the ever-increasing weight of wire paid out. Gentle rope handling and a controlled environment help to safeguard the integrity of the fiber rope.

MacGregor says that its fiber-rope cranes use a novel capstan, developed by Parkburn, as a traction winch. It consists of two interlocking drums slightly angled and offset in relation to each other. The drum geometry creates a natural and stable helix without generating any fleeting forces, so the rope does not twist on the drum as it is gently de-tensioned. The winch system can be delivered with digitally-controlled electric or hydraulic-drive units. Features include integral active-heave compensation and power regeneration capabilities.

The open design of the winch also assists with rope cooling, further assisting in eliminating the heating and degradation problems associated with on-load fiber ropes stored on winch drums. Importantly, it can accommodate non-uniformities resulting from splices in the rope.

MacGregor says that it has also developed a modular fiber-rope retrofit solution, which is based on the same technology. This allows customers to convert their existing wire-rope cranes to fiber-rope versions, unlocking their full potential. •