Subsea construction vessels can deploy heavier equipment in deeper waters, said experts during Riviera’s ’Do more with less: with high-performance fibre rope for efficient subsea hoisting’ webinar
Energy companies could employ smaller vessels to install and remove subsea systems in deepwater oil and gas construction and decommissioning projects worldwide if they have cranes equipped with fibre rope instead of steel wire.
Despite these benefits, fibre rope solutions are not yet in widespread use, although there is greater interest from vessel operators to invest in them.
During the NOV Rig Technologies-sponsored webinar, TechnipFMC presented its motivation to use fibre rope solutions based on operational experience.
DNV GL talked about the safety aspects of using fibre rope for subsea installations and developments in certification.
Hampiðjan Offshore outlined specific requirements for ropes in subsea applications and NOV described specific lifting equipment solutions.
The panel consisted of TechnipFMC UK research and development technical manager for structures and lifting David Cannell, DNV GL senior principal specialist for fracture mechanics and non-metallics Vidar Åhjem, Hampiðjan director David Waage and NOV product line manager for lifting and handling Ronny Hoff.
Mr Cannell said using fibre rope on subsea construction vessels such as Skandi Santos, Skandi Acu, Deep Energy and Aker Wayfarer demonstrated the benefits in enabling much heavier hoisting in deeper waters. “Fibre rope buoyancy means it is neutral [weight] in water, increasing the capacity in deep water,” he said.
Another benefit is the ability to replace sections of fibre rope during maintenance without impacting performance or causing lengthy vessel downtime.
“Fibre rope improves vessel operations with ease of operation, lowers costs, reduces lifetime maintenance costs and creates significant time savings,” said Mr Cannell.
He said these advantages will drive more interest in using fibre rope for subsea lifting. “Our industry needs to work together to get the technology adopted,” he said. “Then the floodgates will open. We are getting there – we want to make sure fibre rope works properly.”
There was consensus from the panel for wider industry adoption of this technology. For this to happen, existing vessels could be upgraded instead of owners ordering newbuild systems.
Mr Åhjem explained how standards for fibre rope lifting systems were being developed to enable owners to retrofit existing vessels and cranes.
DNV GL’s E407 standard was developed with functionality assurance in mind. Mr Åhjem said there would be further developments to ensure these standards are not equipment specific. “E407 currently takes a standard approach, but we want to make it modular.”
“We want full freedom of choice in functional assurance for equipment that is fit for purpose, to enable retrofitting,” he said.
Mr Waage explained the performance of Hampidjan’s DynIce Warp fibre rope, of which more than 12 km is now in use in maritime sectors.
He said the optimal wire rope should have low weight and high strength, good cycling bending performance, minimum temperature-induced elongation and good spooling performance.
“Fibre ropes combine the raw materials, engineering and the construction,” said Mr Waage. “If we look at the construction, the optimised properties would be high lateral stiffness, steel-like properties, high cross-sectional stiffness and strength member protected from particle ingression and abrasion with a tightly braided cover.”
Optimal materials would have good abrasion resistance, bending properties, limited temperature-induced creep and be able to withstand long-term loads at higher temperatures.
Mr Holt explained further how fibre rope has major weight benefits over steel wire, which leads to lower emissions from offshore construction projects.
“For deepsea operations, a traditional steel wire rope will add significantly to the working load of the crane with increasing depth,” he said.
Whereas, “neutrally buoyant fibre rope enables a given deepsea lifting operation to be performed with a smaller crane and a smaller vessel” said Mr Holt.
He added, “Smaller vessels typically translate to lower vessel day rates and reduced energy consumption, which in turn leads to reduced costs and CO2 footprint.”
Attendees were asked their opinion on benefits and use of fibre rope for offshore subsea lifting applications, the results are below.
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Panellists on ’Do more with less: with high-performance fibre rope for efficient subsea hoisting’ webinar included (left to right) TechnipFMC UK research and development technical manager for structures and lifting David Cannell, Hampiðjan Offshore director David Waage, NOV product line manager for lifting and handling Ronny Hoff and DNV GL senior principal specialist for fracture mechanics and non-metallics Vidar Åhjem.
Are you interested in retrofitting an existing system with fibre rope to increase its efficiency, or are you considering installing completely new systems?
Retrofit only: 11%
Retrofit and new systems: 83%
Only new systems: 6%
The E407 does not provide any detailed guidance or standardisation. Would detailed guidance be of interest for the industry, keeping in mind the risk of limiting freedom of choice?
1 – Invaluable: 18%
5 - No value: 3%
The E407 standard takes an all-system approach, whereas a more modular approach is planned for future versions. Is a modular standard preferable compared to an all-system approach?
1 - Strongly Agree: 35%
5 - Strongly disagree: 3%
If fibre rope winches are adopted, which method would best describe your approach?
Try out and retrofit existing winches <50 tonnes: 28%
Upgrade existing installations to increase capability: 37%
Include in newbuild investment plans: 35%
Are you ready to start using high performance fibre rope for subsea hoisting operations?
Only once more people are using the technology: 22%