Posted on October 20, 2022
DEME Offshore US LLC is to use a new heave-compensated offshore lifting solution on its contract to install the wind turbines for the first large-scale offshore wind installation in the U.S., Vineyard Wind 1.
As we reported earlier, DEME will install the turbines using a foreign-flag wind turbine installation vessel (WTIV) serviced by Jones Act compliant Foss Maritime feeder vessels. To safely transfer the wind turbine components from the heaving feeder vessels, DEME has awarded Dutch motion compensation specialist Seaqualize the first contract for its newly developed offshore lifting device: the Heave Chief 1100. According to Seaqualize, the battery-powered HC1100 is currently the largest active heave compensator in the world. As a balanced heave compensator (BHC), it can compensate a vessel’s heave motions and safely quick-lift loads up to 1,100 tonnes.
The Vineyard Wind 1 project will see DEME transporting and installing 62 wind turbine generators at the wind farm site off the coast of Martha’s Vineyard, Mass. Each turbine will be transported in components from the supply harbor to DEME’s installation vessel Sea Installer using Foss Maritime supply barges.
“We contracted Seaqualize to de-risk the Vineyard Wind project: their solution is a novel, but realistic method to safely transfer the delicate components, minimizing the risk of damage and delays,” said Glenn Carton, project director Vineyard Wind at DEME. “We think this is how feeder barge operations should be done going forward.”
HEAVE CHIEF 1100
Seaqualize has been developing inline balanced heave compensators, specifically for heavy lift, in-air active load control since 2019. Together with Van Oord Offshore Wind, it successfully tested a 600 tonne capacity prototype in November 2021. The HC1100 is based on this prototype and will be the world’s largest and most sophisticated active heave compensator.
Set for delivery in March 2023, the HC1100 has a load-capacity of 1,100 tonnes, required to balance turbine components of the 15 MW generation. It can reach higher quick-lift speeds than the prototype and has a longer stroke to handle the larger motions of smaller supply vessels. It also offers a single lift point for operational efficiency. The new design further minimizes dynamic load fluctuations impacting the crane and offers passive safety procedures. In addition, Seaqualize’s in-house developed “follow-mode” allows the full load to match the movements of the target vessel. If required, quick-lift operations are fully reversible.
Seaqualize says that a number of offshore installation contractors are currently investigating how to include the Heave Chief into their feeder-barge setups and that it expects to announce an additional contract before the end of the year, . Alongside the HC1100, the company’s first full-scale BHC prototype is currently being upgraded for working loads up to 750 tonnes