VESSEL REFIT | Orient Constructor – Construction vessel rebuilt as walk-to-work asset for Taiwan’s Dong Fang

Dong Fang Offshore (DFO), a subsidiary of Taiwan’s Hung Hua Construction, has begun operating the first subsea construction and walk-to-work (W2W) vessel to be owned by a Taiwanese company.

Originally built by Norwegian shipyard Kleven Verft as a construction support vessel (CSV) in 2014, the DNV-classed Olympic Athene first operated as part of the fleet of Olympic Shipping. The vessel later became more popularly known as Seabed Constructor, as it was under this name that it was used for a number of undersea shipwreck discoveries such as the discoveries of the Argentine Navy submarine ARA San Juan, the South Korean large ore carrier Stellar Daisy, the French submarine Minerve, the German World War I cruiser Scharnhorst, and the American battleship USS Nevada during the 2018-2020 time frame. The vessel was also twice deployed to assist in the search for the still missing Boeing 777-200ER aircraft of Malaysia Airlines Flight 370, which disappeared in 2014.

Following its acquisition by DFO in April 2021, the vessel underwent an extensive conversion to enable it to better support commissioning and maintenance activities in the Taiwanese offshore wind industry. The vessel has now been reflagged to Taiwan and appropriately renamed Orient Constructor, and its array of equipment includes a 250-tonne active heave compensated main crane and a 3D motion-compensated gangway.

Accommodations are available for 102 persons, and the aft deck’s total area of 1,300 square metres has capacity for 1,000 tonnes of assorted cargo. Separate cargo holds meanwhile have a total area of 346 square metres.

Design and engineering were performed by Norwegian naval architects Marin Teknikk, which also assisted in the vessel’s subsequent W2W conversion.

The vessel has an LOA of 115.4 metres, a beam of 22 metres, a maximum draught of 7.12 metres, and a deadweight of 6,840 tonnes. The flight deck can accommodate two 16-tonne helicopters while a dedicated hangar located aft of the accommodation area can house remotely operated vehicles (ROVs). The ROVs are deployed and recovered via a pair of Ultamec launch and recovery systems (LARS) and a 7.2- by 7.2-metre moonpool.

The accommodation block includes 24 one-berth cabins, 39 two-berth cabins, an onboard hospital, four lounges, a mess room, two conference rooms, two client offices, and a gym.

Power is provided by five Caterpillar 2,230ekW engines driving two 3,000kW Contaz propellers to deliver a maximum speed of 14.1 knots and a service speed of 12.5 knots. A 1,700kW generator set supplies electrical power when the vessel is in harbour. Thrusters at the bow and stern work in conjunction with the vessel’s Kongsberg DP2 system to ensure adequate station keeping.

The conversion work on Orient Constructor was performed in Taiwan and completed in late 2021. Earlier this year, the vessel concluded W2W trials at the Greater Changhua 1 and 2a offshore wind farms. The trials validated the ability of the vessel to conduct crew transfers during Taiwan’s harsh weather winter period at both the offshore substation and offshore foundations. Wave buoy data during the trials showed significant wave heights of up to four metres at the site.

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