Seaqualize and Van Oord test inline Active Heave Compensator

4C Offshore | Tom Russell
By: 22/11/2021 Seaqualize

Seaqualize and Van Oord have completed offshore trials for the inline Active Heave Compensator (iAHC), the DNV certified ‘Delta600’. The offshore lifting tool was tested for fixed-to-floating, floating-to-fixed and floating-to-floating transfers of 300mT loads.

Since December 2019, Seaqualize, developed the  iAHC: a tool specifically designed for heavy lift, in-air load control. The tool is designed to balance and transfer loads of up to 600mT in mid-air, while the barge or crane vessel is heaving up and down in heavy seas of up to Hs2,5m.

During 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 operational 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.

Wouter Dirks, Innovation Manager at Van Oord: “The offshore tests showed that the unique technology in the Delta will enable controlled offshore lifts during challenging feeder barge operations”.

During the tests, several very gentle set downs and quick liftoffs have been performed. Nautical research institute MARIN observed that the tool is able to control the load within an envelope of 5cm, with minimal accelerations and dynamic crane forces. Liftoffs where performed with 90% of the load already in the hook of the crane before liftoff, while still fully compensating all waves. This reduces impact loads on the load, crane and rigging and results in a controlled and stable liftoff. Finally, the tool showed off its “follow-mode”, where the test weight could actively match all heave motions of the target vessel, to further minimize set-down impact for floating to floating set downs.

This offshore trial was also the last step in full DNV product certification as a standard offshore lifting tool. The research project was executed with a grant from the Ministry of Economic affairs of the Netherlands, and included Dutch research agency TNO besides the offshore testing partners MARIN, Van Oord Offshore Wind and Seaqualize.

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.