While monohulls remain king for high-deadweight applications, large high-speed catamarans win out for speed, economy and safety
At this year's Middle East Offshore Support Journal Conference in Dubai, Australian shipbuilder Austal’s offshore global sales manager Chris Pemberton presented a review of developments in the fast supply and crew transfer vessel (CTVs) sector.
He noted that the use of smaller CTVs in the wind sector has resulted in a standardisation of design, a result of industry regulations such as the requirement for sub-24M load lines, capacity for 12 passengers, common boat-landing dimensions and load limits at turbine transition pieces.
“If there is a lesson to be learned it is that there are opportunities for oil and gas maritime solutions [to be] applied to offshore wind,” he said, noting that monohulls and large catamaran CTVs could play a part in the sector, which is set to grow significantly in the next 10 years and beyond.
Mr Pemberton also shared comments from operators of fast supply vessels and CTVs around the world, surveyed by Austal on a range of issues.
“Innovative high-speed large catamarans have proved their worth in terms of optimising safe and economic crew-change capability”
71% of those surveyed said they saw short-term charters as tending to prevent design innovation, with respondents noting that short-term charter periods always favour existing vessels over newbuilds, and that innovative designs require backing from financial institutions which tend to prefer long-term contracts to ensure cashflow for repayments.
“The crewboat industry is constantly looking for innovations in a competitive world,” he said, adding: “Incremental changes in speed and comfort are almost universally sought.”
However, he noted, “There is a classic chicken-and-egg situation,” with charterers unwilling to risk unproven designs, but new designs unable to establish themselves without long-term commitment from charterers. Designers and shipyards proposing proven technologies for use in new applications is one way to overcome this, he said.
Examples include high-speed catamarans, which have proved their worth in the ferry sector, and walk-to-work gangways.
Where international and national oil companies (IOCs and NOCs) have taken a long-term view, innovative high-speed large catamarans have proved their worth in terms of optimising safe and economic crew-change capability.
Owners commented that IOCs and NOCs are increasingly tending to favour such fast crewboats over helicopters, with cost a major driver, and that such vessels are able to replace sizeable helicopter fleets, Mr Pemberton said.
Speed, comfort and stability were among the main priorities in the design of such vessels, with 71% of owners surveyed citing speed, amongst other factors, as key in changing over from helicopters.