Damen ASV 9020/SOV successfully completes first projects in the offshore industry
Representing more than four years of Research & Development, the Damen Accommodation Support Vessel 9020 – known as the Damen Service Operations Vessel (SOV) in the wind market – successfully completed its first projects in the offshore industry in recent months. Specifically designed for the transfer and accommodation of technicians, the new vessel type guarantees safe and comfortable access to both wind turbines and platforms.
As the first ASV 9020/SOV – the ‘Bibby WaveMaster 1’ – enters service Damen outlines the rigorous testing period the vessel underwent, which included a novel use of simulator technology.
Initially, offline numerical simulations of the vessel and a generic DP system were carried out during the concept design stage. Then to prove the vessel’s ability to transfer and accommodate people, Damen undertook a series of seakeeping tests at Maritime Research Institute Netherlands (MARIN). Damen also asked MARIN to provide input for the power management system by performing numerical simulations.
The Offshore Basin model tests encompassed a vendor specific, Dynamic Positioning system and the walk-to-work telescopic gangway. These assessed the vessel’s DP capabilities during the turbine/platform approach and the vessel’s ability to keep position alongside, as well as the extension and touchdown of the walk-to-work gangway.
Results from these tests were input into the setup for the final Hardware In the Loop (HIL) simulator that combined the vessel, DP system and the gangway. Importantly, the full DP system and the walk-to-work arm were used exactly as they would be on board the Bibby WaveMaster 1 and the integrated setup was combined with the route planner. The HIL simulator has now been installed at Damen’s headquarters.
Jorinus Kalis, Damen Manager Development, R&D, explains: “Damen is always being asked for proven technology but on the other hand, innovative, ground breaking vessel design. Because we have used simulation technology in a specific way, we believe this vessel provides both.
These model tests enabled Damen to optimise the turbine or platform approach strategy and to assess the combined system performance of the ship.
Crucially, the simulation methods provided realistic operational performance data, not just trial data. “This was a first for Damen. It enabled Damen to prove the vessel’s capabilities and our launching customer – Bibby Marine Services Ltd – could pass this information on to its clients as well.”
Realistic performance data
Damen and Bibby were able to get the full picture about how the vessel responded when performing maintenance activities – in this case following a planned route between wind turbine locations. They considered the safest and most efficient way of getting the technicians safely on and off the turbines, before moving on to the next one. This enabled Bibby to see if the maintenance sequence could be done in a certain time, and how many turbines could be maintained in a designated number of hours.
The HIL simulator enabled them to compare operational performance. “We had ‘concrete’ information about how many maintenance operations can be carried out in a year at a given wind farm. We can see what happens in the field rather than in ‘ideal’ test conditions.
“Because this was a completely new design, and not similar to any vessels we have built before, we wanted to test the vessel itself but also the process behind it. We needed to understand the functional requirements and also had to consider the specific mission of the end user.”
Usually Damen would test separate systems before the trials – the engine and propeller etc. he says, but this is the first time the shipyard group had carried out combined tests on all of the relevant control systems together.
With the desktop numerical studies and simulations, Damen and Bibby had the advantage that we could test the possibilities and immediately see their operational impact, adds Jorinus.
The integrated approach enables Damen to know what it can guarantee in terms of uptime. And uniquely Damen could include the trial data but also the operational performance of the vessel in the contract to show that the simulations indeed give a realistic estimate of the real life performance of the vessel.
Jorinus says: “This also helps to de-risk offshore operations. Before the vessel goes into the field there is a proven design, founded on scientific research. This makes it much easier to predict workability and uptime.”
During the tests Damen discovered that the SOV could remain at the turbines for longer than it had originally expected. The tuning of the DP system meant that it became ‘stiffer’, reducing the maximum movement, thereby increasing the operational envelope.
The HIL simulator enables Damen to prove that the vessel can manage 2.5 m significant wave heights in any conditions, even in challenging sea states, in wind speeds up to Bft7. The SOV’s ability was then proven in the field when operating in a storm in the North Sea. The Chief Engineer of the Bibby WaveMaster 1 said:
It’s windy over here and the sea is quite rough but the BWM1 is an excellent sea boat and you would never know you were at sea half the time. She doesn’t move, and the thrusters run less than 10% in DP. I’ve never seen a ship perform so well in wind and swell. It is very impressive.
Test maintenance plans in advance
As wind farms go further offshore, it is very useful to test a maintenance plan and see if it can still work in a certain sea state. If you can stretch the operational envelope by 10% this is tremendously significant.
And for the oil & gas sector, Jorinus says, exchanging crew by means of a vessel represents a significant reduction in costs compared to using jack-ups and helicopter transfers. This results in a substantial cost reduction throughout the O&M phase of smaller platforms.
Shortly after the Bibby WaveMaster 1 was delivered she went straight to work in the southern North Sea. Although she had been expected to go directly into the offshore wind industry, her first project was for a maintenance job on a platform for a leading energy giant. This was shortly followed by a project in the renewables sector at the Galloper offshore wind farm. “It is very satisfying to see that after all these years of R&D, we have developed a new vessel type which is really being appreciated in both the oil & gas market and in the offshore wind industry.”