Heavy Lifters for Offshore Renewable Market

Offshore Heavy Transport (OHT) will enter the offshore renewables and installation market with a new heavy lift transport and installation vessel, a customized Ulstein Alfa Lift design developed by Ulstein Design & Solutions BV (UDSBV) and OHT.

There is one firm order with three options to build the ship at China Merchant Heavy Industry (CMHI), ready for action in 2021.
The dynamically-positioned, 48,000 DWT vessel is designed to perform heavy lift crane operations with the main deck submerged, a patent-pending design combining the benefits of a semi-submersible transport vessel with a large, 3,000 mt lifting capacity main crane from Liebherr.

The vessel is designed to match the future requirements of the offshore wind industry, allowing 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.

“We started the development of the Ulstein Alfa Lift idea 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,” said Edwin van Leeuwen, managing director, Ulstein Design & Solutions BV.

“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,” said Torgeir E. Ramstad, CEO at OHT. “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.’”

Vessel Dimensions
Length, o.a.  216.3 m
Length, bpp   204.3 m
Beam (molded)  56 m
Depth (main deck)  12.6 m
Draft (design)  8 m
Draft (submerged max.)  27.6 m
Service speed  13 knots
Installed power  4 x 6,875 kW
Propulsion thrusters  3 x 5,500 kW
Retractable thruster  1 x 3,000 kW
Tunnel thrusters (fwd)  3 x 3,000 kW
Positioning system  DP 2
Class  DNV-GL
Deck strength  30 t/m2
Complement  100 persons