Fibre rope for deep-water subsea applications
The newly developed hybrid system is available for various crane capacities
A result of more than ten years of research and development, the hybrid system combines the benefits of lightweight fibre rope with the well-tested performance of conventional steel wire for safe and effective active heave compensation.
The company’s research has shown that the thermal behaviour of fibre rope means that it is not suitable for active heave compensation because its performance is unpredictable and hard to measure. It would therefore require a sophisticated cooling system to be incorporated into a crane’s safety system which the company does not view favourably.
Cees van Veluw, the company’s product manager for cranes, explained: “We strongly believe in the future of cranes with fibre rope included – not just because of a capex and opex evaluation, but also to further shift the limit of what can be deployed in subsea applications. Our extensive R&D programme, which has been active for over ten years, has shown that the fibre rope with the best lifetime performance would require some serious active cooling on the crane when performing active heave compensation. Having the active cooling system as an essential part of the crane’s safety system is not the way we see robust and reliable crane design.”
The new hybrid system enables the fibre rope to be spooled efficiently with Huisman’s Traction Winch and Storage Winch set-up, while the process of active heave compensation is carried out with steel wire rope on a direct winch. Various capacities are available: for traditional knuckle boom cranes, 120-tonne and 240-tonne versions are available, while the recently introduced Hybrid Boom Crane provides greater capacities of 400 tonnes and 600 tonnes. The hybrid system enables a full load at all depths, the company claims, so that 600-tonne loads can be handled at depths of 4,000m and beyond.
