Damen Shipyards Group has carried out tank testing of its 70-metre Fast Crew Supplier (FCS) 7011. The tests were carried out at the Delft University of Technology (TU Delft) with a 2.8-metre long model. Intended for long distance crew transfer operations, the Damen FCS 7011 will offer the offshore oil & gas industry a safe and cost-effective alternative to helicopter flights.
In developing the FCS 7011, on-board comfort has been one of Damen’s central design parameters. Consequently, the company has executed a large number of simulations to investigate seakeeping characteristics.
“We have used these simulations to see which hull form gives the optimum comfort levels,” explains Albert Rijkens, Damen Product Portfolio Manager Research. “The aim of the model testing at TU Delft was to validate those numerical results.”
Performing tests at 30 knots and 40 knots in waves of 2-3 metres significant wave height, seakeeping was a major aspect of the testing. The results were positive; the hull design and the application of the Sea Axe bow allows the vessel to reach high speeds through waves while meeting predetermined criteria for comfort levels.
“In fact, what we see is that ship movements become calmer as the speed increases. This is because the forward energy of the vessel allows it to go through the waves, instead of going over them. At the same time the Sea Axe bow shape reduces any uncomfortable slamming that might occur during high speed transits.”
Another aspect of the tank testing was to study vessel resistance at speed. “Our results showed that, due to its long and narrow hull, the FCS 7011 has relatively low resistance.”
The tests were also an opportune moment to trial the so-called Ride Control System positioned at the stern of the 1:25 scale model of the FCS 7011. “This system measures ship movements and based on these signals it continuously determines the position of the active control mechanisms. The effectiveness of the system – enabling us to improve comfort levels even further – was also validated in these tests.”
The FCS 7011 tank tests represent the continuation of the strong working relationship between Damen and TU Delft. “They have definitely played an important role in this project,” adds Mr Rijkens. “This started in the preliminary seakeeping simulation stage to reach the optimum hull form that we have used. And now, using their tank testing facilities, to validate our ideas and our calculations.”
With these tests yielding positive results, and further testing planned in this year, Damen is closer to finalising the design of this new vessel. As Mr Rijkens notes, the FCS 7011 marks a significant step for the safe and fast transfers of offshore personnel. “Offshore oil and gas operators currently use helicopters as their principal method to transfer crews to and from platforms. However, there is a very clear desire from the industry to change the logistical model with the introduction of new generation of crew change vessels.”
“They need an alternative – and the FCS 7011 fills the gap between the current crew change vessels and helicopters. It will achieve this by being able to carry up to 150 passengers in business class comfort at speeds of up to 40 knots.”