Novel Lifting Tool Passes Offshore Tests

Seaqualize, Van Oord, and the nautical research institute MARIN have trialled Seaqualize’s inline Active Heave Compensator (iAHC), the Delta600.

The offshore lifting tool underwent 62 hours of offshore testing in the Dutch North Sea, Seaqualize said.

Delta600 was tested for fixed-to-floating, floating-to-fixed, and floating-to-floating transfers of 300mT loads. The tool is DNV certified and ready for work, Seaqualize said.

Seaqualize has been developing this world’s first iAHC since December 2019. Delta600 is specifically designed for heavy lift, in-air load control. The tool can 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, according to Seaqualize.

This functionality is said to be of great benefit during offshore wind turbine installation or when lifting delicate loads to and from floating supply vessels or barges.

By engaging the Delta, the operational time for installation contractors greatly increases, especially in the hard-to-work winter, autumn, or spring seasons, Seaqualize said. The tool is said to offer contractors greater planning flexibility, and lifting crew a higher level of control, safety and efficiency.

With the worldwide increase in demand in the offshore wind sector, increased capacity and efficiency is greatly needed. In the wider offshore community, perfectly controlled lifts are equally essential to safe, timely, and efficient operations, Seaqualize said.

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 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. Such ’feeder barge’ operations are essential in for example the US wind market. Transferring the most delicate parts of a wind turbine offshore is new to the market, and such operations comprise demanding lifting conditions and a new set of tools, according to Seaqualize.

Wouter Dirks, Innovation Manager at Van Oord, said: ”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. MARIN observed that the tool is able to control the load within an envelope of five centimetres, with minimal accelerations and dynamic crane forces. Liftoffs were performed with 90 per cent of the load already in the hook of the crane before liftoff, 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 said. 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.

600mT Lifting may seem like a lot, it’s equivalent to three Boeing 747s, but offshore wind turbine sizes are growing explosively, thus requiring ever-bigger lifting tools for still very delicate components, Seaqualize said.

Currently, the company 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.