VESSEL REVIEW | Haiyang Shiyou 302 – Chinese LNG bunkering vessel for inland and coastal waters

China National Offshore Oil Corporation (CNOOC) has taken delivery of a new LNG bunkering and supply vessel built by compatriot shipyard Nantong CIMC Sinopacific Offshore and Engineering (CIMC SOE). Haiyang Shiyou 302 (海洋石油302; "Offshore Oil 302") is the first LNG bunkering and supply vessel ever to be acquired by CNOOC as well as the first Chinese-built LNG bunkering and supply vessel capable of river and sea operations under summer and winter conditions.

Large capacity and improved efficiency

The newbuild has an LOA of 133 metres (436 feet), a beam of 22 metres (72 feet), a draught of five metres (16 feet), a depth of 11 metres (36 feet), a deadweight tonnage of 6,600, and an electric propulsion system to help reduce noise and emissions. Two IMO Type C LNG cargo tanks have a total capacity of 12,000 cubic metres (420,000 cubic feet), which is the equivalent of the monthly LNG consumption of approximately 480,000 Chinese households.

The vessel's shallow draught will allow safe operations in inland as well as coastal waterways. The deck layout includes four bunkering stations, a port side high-level header area, and a starboard side low-level header area to enable ship-to-ship (STS) bunkering to be carried out on both smaller and larger recipient vessels. The bunkering capacity is rated at 2,000 cubic metres (70,629 cubic feet) per hour.

The cargo tanks each feature a saddle-type base with strong pressure-bearing capacity and single-layer protection insulation. A gas combustion unit is fitted for the recovery of any vapour that would otherwise be lost during bunkering operations.

Two bow thrusters will meanwhile provide additional lateral manoeuvrability for berthing/unberthing, accurate alongside positioning during STS operations, and navigating in restrictive port waters.

The propulsion setup also includes two 1,380kWe generators and two azimuthing thrusters each housing a pull-type paddle propeller that can deliver a 0.25-knot higher speed compared to a conventional propeller using the same main engine output. This also allows the vessel's fuel consumption to be reduced by as much as 1.18 tonnes per day without any reduction in the average operating speed. The propulsion system also delivers a maximum speed of 13 knots.

Design emphasising versatility and safety

The vessel itself adopts the so-called "invertible mast" design where the mast can be retracted using hydraulic pressure to reduce the overall height, allowing safe passage underneath bridges.

Finally, in addition to bunkering and supply, the vessel can also perform inerting, cooling, and air displacement services for LNG-fuelled ships before they put to sea.

Design work on the vessel was completed by Shanghai Merchant Ship Design and Research Institute (SDARI) in compliance to China Classification Society rules including those that cover unlimited navigation and sailing in ice class B areas with current speeds of up to 1.5 knots, wind speeds of up to 26.8 knots, and wave heights of 2.5 metres. The vessel also complies with the requirements for safe navigation even in extreme low-water levels along some portions of the Yangtze River.

Haiyang Shiyou 302's area of operations will encompass the Yangtze River and Bohai Bay, where it will provide bunkering services for other vessels as well as supply of LNG at shore terminals. CNOOC subsidiary CNOOC Energy Development will be responsible for operation of the vessel.