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OOS muscle for hire

Offshore Marine Technology: 2nd Quarter 2021



Offshore operator OOS International has noted an increase in charter enquiries for its newly built semisubmersible heavy-lift crane accommodation vessels OOS Serooskerke (pictured) and OOS Walcheren, both constructed by China Merchants Industry Holdings.


“Currently, OOS is discussing the charter of the vessels for several offshore wind projects in Asia [and] Europe,” the operator has stated, adding: “OOS and partners might also provide the associated project management, engineering and execution of the project…the total number of vessel charter days in discussion for the aforementioned projects exceeds 1,000 days.” The operator is also participating in decommissioning-related tenders.


Like its twin sister, OOS Serooskerke has a length of 137.75m, a breadth of 81m and a moulded depth of 12m. The ship was developed with an operational draught of 20m, increasing to 26.4m max during heavy-lift duties, and offers 3,800m2 of clear deck space, strengthened to 15tonnes per m2. The vessel can also accommodate up to 750 offshore workers, housed in 90 single-, 318 double- and six four-person cabins.


OOS Serooskerke is equipped with two heavy-lift cranes, each with a SWL of 2,200tonnes at 22.1m. These are complemented by two Huisman service cranes: one rated 36tonnes, the other 60tonnes. The vessel can also undertake subsea construction work and subsea support down to 3,000m.


The ship is powered by eight STX 8L32/40 engines, rated 4,000kW apiece, driving six 3,800kW Thrustmaster fixed-pitch azimuth thrusters and enabling a transit speed of 11knots. The vessel’s DP3 system was supplied by Kongsberg Maritime.


The heavy-lifter has also been granted ABS’ Integrated Software Quality Management (ISQM) notation, in recognition of OOS taking a risk-based approach to the onboard power management, DP, ballast/bilge and loading computer systems.