The agreement with China Merchants Heavy Industry (CHMI) in Jiangsu will put OHT into the wind turbine installation market for the first time.
The vessels will be GustoMSC’s NG14000XL-G (pictured) and will feature telescopic 2500-tonne cranes with maximum lifting heights of up to 165 metres, OHT said.
They will be capable of operating in water depths of 65 metres.
The first jack-up is due to be delivered in early 2023, while a delivery date for the second has not been disclosed.
“Through this initiative, OHT firmly establishes its position as a leading, fully integrated transport and installation company for offshore wind,” said OHT chief executive Torgeir Ramstad.
“We are responding to client concerns about the lack of capable vessel capacity in the booming offshore wind market. We hear them applauding the development of a capability by a single company to handle the transport of next generation foundations and turbines.”
OHT said battery hybrid solutions and a sophisticated electrical control system will help reduce emissions on the new jack-ups by 20% compared to similar sized crane vessels.
The jack-ups have also been prepared for hydrogen fuel cells as a future option, which could further cut their emissions profiles.
The order is OHT’s first since the company entered the foundation installation market when it unveiled its semi-submersible foundation crane vessel Alfa Lift in 2018.
Alfa Lift is due to be delivered next year and will install all monopile and transition piece foundations at the 2.4GW Dogger Bank A&B complex from 2022, which SSE and Equinor are developing.
VIND Offshore Installation AS founder Rune Magnus Lundetræ, who developed the concept and business model for OHT’s turbine installation business, said the company is well placed to for success in the new market.
“We look forward to our involvement in the world’s first integrated pure-play transport and installation company in the offshore wind segment,” he said.
Lundetrae said the company could further grow its fleet via an “expansion of the Alfa Lift series of foundation vessels and possibly more jack-ups through exercising the options".
