Seaqualize has successfully completed offshore trials with its inline active heave compensator (iAHC) system, the Delta600.
Together with testing partners Van Oord and nautical research institute MARIN, the offshore lifting tool was tested for fixed-to-floating, floating-to-fixed and floating-to-floating transfers of 300-tonne loads. The Delta600 is now DNV-certified and ready for work.
Seaqualize has been developing the system since 2019. The tool can balance and transfer loads of up to 600 tonnes in mid-air, while the barge or crane vessel is heaving up and down in heavy seas.
This functionality is beneficial during offshore wind turbine installations or when lifting delicate loads to and from floating supply vessels or barges, said Seaqualize. By engaging the Delta, the operational time for installation contractors greatly increases, especially in the hard-to-work winter, autumn or spring seasons.
During these offshore trials, the Delta600 lifted a test weight to and from the floating supply vessel Rem Trader, using Van Oord’s jack-up crane vessel Aeolus, in both jacked and floating conditions. These floating-to-floating and floating-to-fixed lifts were tests of typical challenges in the offshore wind industry: installing turbine components using a floating vessel, or picking up components from a floating supply vessel.
During the tests, several very gentle set downs and quick lift offs were been performed. MARIN observed that the tool is able to control the load within an envelope of 5 cm, with minimal accelerations and dynamic crane forces. Lift offs were performed with a solid 90 percent of the load already in the hook of the crane before the lift, while still fully compensating all waves. This significantly reduces impact loads on the load, crane and rigging and results in a controlled and stable liftoff, Seaqualize explained. Finally, the tool demonstrated its ‘follow-mode’, where the test weight could actively match all heave motions of the target vessel, to further minimise set-down impact for floating-to-floating set downs.
Currently Seaqualize is designing the next version, the Delta1000, equipped for all next generation wind turbine components. Further conceptual improvements include the addition of single lifting points for quick-connect systems, and smart controlled tugger winches for supreme control in the horizontal plane. At the same time, the company will further develop its offshore operational support capabilities, by deploying the Delta600 in the field.