Chinese shipbuilder Shanghai Zhenhua Heavy Industry is moving into the wind-farm sector after clinching a domestic order for service operation vessels (SOVs).

The group has been selected by Shanghai Electric Wind Power to build two ships featuring motion-compensated walk-to-work gangways and DP2 dynamic positioning capabilities.

The first SOV will accommodate 60 workers, with the second housing 100 people.

The vessels are set to be delivered in 2023 and will be used for maintenance work at offshore wind farms in China.

The shipyard company is also owns heavylift vessels through subsidiaries Shanghai Zhenhua Shipping and ZPMC Red Box Energy Services.

Clarksons lists the fleet at 36 ships, with a diving support vessel and a pipelay unit on order at its own yard.

Rushing to meet the deadline

Clarksons Research said that as developers seek to accelerate construction to meet the 2021 Chinese state subsidy deadline at the end of the year, demand for wind-farm vessels has significantly increased.

At the beginning of July, turbine installation vessel usage in China was 97%, with charter rates reported to have quadrupled in Guangdong province.

To meet demand, several owners have equipped barges with crawler cranes and are converting idle oil and gas assets to provide additional installation capacity.

In the year to date, eight such conversions and upgrades have been agreed, with eight vessels delivered.

Prominent among these jobs is the unwanted Octabuoy, a semi-submersible oil and gas production unit completed in 2013 by Cosco Nantong Shipyard.

The yard has said it will convert the vessel into a heavylift/crane ship for offshore wind construction work in China.

Unusual design

The $99m Octabuoy was originally built for ATP Oil and Gas but was never put to work after ATP filed for bankruptcy in 2012.

The unusual octagon-shaped unit is designed to work in water depths between 1,500 and 3,000 metres. Cosco started construction on the vessel in 2008.

The new work, which involves adding a forecastle deck, poop deck and living quarters, is set to be completed later this year.

Shanghai-based Xiong Cheng Offshore Engineering is said to have chartered the ship.

Elsewhere, the Yantai CIMC Raffles shipyard has turned the H213 jack-up drilling rig into a wind turbine installation vessel for CNPC Offshore.

The ship has been equipped with an 800-tonne main crane and will carry out work at the Shandong Peninsula South 3 offshore wind farm in China.