The new vessel is a customised ULSTEIN Alfa Lift design developed by Dutch design company Ulstein Design & Solutions BV (UDSBV) in partnership with OHT.

China Merchant Heavy Industry (CMHI) will handle the construction of the first vessel. The vessel will be available for construction and installation activities by early 2021.

Ulstein Design & Solutions BV managing director Edwin van Leeuwen said: “We started the development of the ULSTEIN Alfa Lift idea back in 2015 with the driver to increase the safety of submerged operations and at the same time increasing the operability window for subsea installations using a crane.”

OHT claims that 48,000 deadweight tonnage (DWT) vessel will the ability to perform heavy lift crane operations with the main deck submerged.

The vessel has been designed to combine the benefits of a semi-submersible transport vessel with a large, 3,000 metric ton lifting capacity of the main crane from Liebherr.

It is claimed that the vessel has the capabilities to meet the future requirements of the offshore wind industry, which allow it to transport and install up to 10 x 1,500t ultra-large jacket foundations or 11 x 2,000t XXL monopiles plus transition pieces for the largest anticipated Wind Turbine Generators.

OHT CEO Torgeir E. Ramstad said: “It is great to work with such capable people. When we approached Ulstein with our intended strategy to enter the offshore renewables market and the idea of adding crane capacity to a semi-submersible heavy lift transport vessel, UDSBV presented their Alfa Lift solution on the spot.

“That was a direct ‘hit’, as it allows us to enter the installation market, at the same time expanding on our capabilities in OHT’s core market.”