A dynamically-positioned, 48,000 DWT heavy lift transport and installation vessel for the offshore wind industry. The design combines the benefits of a semi-submersible transport vessel with a large, 3,000 mt lifting capacity main crane. Can perform heavy lift crane operations with the main deck submerged.

Vessel type

Heavy lift

Built by

China Merchants Heavy Industry (CMHI), China



Owned by

Seaway 7

Designed by

Ulstein Design & Solutions B.V.

Ordered by


Principal dimensions

216.3 m
56 m
Draught (max):
submerged 27.6 m
Speed (max):
13 kn
100 POB

Note: Subject to selected variant configuration


Propulsion thrusters:
3 x 5,500 kW
Retractable thruster:
1 x 3,000 kW
Tunnel thrusters (fwd):
3 x 3,000 kW
Liebherr main crane:
3,000 mt
Deck strength:
30 t/m²
Positioning system:
DP 2

The vessel is constructed by China Merchant Heavy Industry (CMHI) for delivery in 2022. The vessel’s capabilities match the future requirements of the offshore wind industry, allowing her 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.

The 'Seaway Alfa Lift' will be capable of installing all types of bottom-fixed offshore wind foundations and will also transport and install topsides and subsea modules, in addition to other heavy cargoes within oil and gas.

The vessel’s crane will have a maximum lifting capacity of 3,000 tonnes at 30 metres and 1,000 tonnes at 76 metres outreach. The 216.3-metre vessel will also have a 10,000+ m² “smart deck” that can carry up to 14 giant monopiles per trip and will be fully submersible to a depth of 14.66 metres.

Ship history

March 2019: Steel cutting

October 2019: Keel laying

November 2019: Contracted for transport and installation of foundations for Dogger Bank Offshore Wind Farm

January 2020: Nominee for the Offshore Renewables Award

February 2021: Launching at the CMHI yard

October 2021: The new build was originally ordered by OHT (Offshore Heavy Transport). OHT has merged with Subsea 7’s renewables business unit to become Seaway 7 effective from 1st October 2021.

'Seaway Alfa Lift' will transport and install all monopile foundations and transition pieces for each of the two 1.2GW phases of the project between 2022 and 2024. The Dogger Bank Wind Farm is being developed by SSE Renewables and Equinor, with the first power expected in 2023.

Please contact us for more information

Ulstein Design & Solutions B.V.

Cornerstone Building (6th floor)
Rotterdam Airportplein 32
3045 AP Rotterdam
The Netherlands

Tel: +31 10 475 00 11