VESSEL REVIEW | Zhanjiang Bay No 1 – Chinese aquaculture platform boasts autonomous navigation capability
China's Dajin Heavy Industries has delivered a new aquaculture vessel capable of operation in offshore waters.
Zhanjiang Bay No 1 (湛江湾1号; Zhanjiang Wan No 1) was designed by Zhanjiang Bay Laboratory and is fitted with energy management systems. Construction was done in compliance with China Classification Society requirements.
The self-propelled vessel has a steel hull, an LOA of 154 metres (505 feet), a beam of 44 metres (140 feet), a depth of 24.25 metres (79.56 feet), a maximum draught of 20 metres (66 feet), 12 breeding cages with a total capacity of 80,000 cubic metres (18 million gallons), and a dynamic positioning system. The onboard cages will have an annual production capacity of 2,000 tonnes of tuna, catfish, and other premium species.
Electric propulsion allowing for ease of positioning and relocation
The platform adopts an innovative structure that combines a bow with a column-stabilized frame and is equipped with a bridge, an accommodation block and a helicopter deck to facilitate personnel changes far from shore.
The stern is equipped with two azimuthing thrusters while the bow is equipped with two side thrusters. These are all electrically driven and will be operated in conjunction with the dynamic positioning and mooring systems.
The main thrusters will meanwhile allow the vessel to relocate as necessary to find the most optimal areas for fish harvesting if factors such as weather, sea conditions and lower fish populations make the present area unsuitable for aquaculture operations. Harvesting can be done even in waters as deep as 10,000 metres (33,000 feet), making the vessel suitable for deployment in some parts of the South China Sea.
Broad selection of intelligent operating and monitoring systems
The cages are made of HDPE and are fitted with fully transparent mesh coating to permit a more efficient exchange of internal and external seawater. This natural water purification process helps lower the risk of disease among fish, thereby ensuring better quality that could yield higher prices in the market.
Each cage also has systems for feeding, feed storage, fish harvesting, breeding monitoring, net cleaning, net tension adjustments, and even collecting dead fish. The condition of the tanks themselves and the fish contained in them can be remotely monitored in real-time from shore.
The monitoring systems assess parameters such as water temperature, oxygen levels, and fish health. An AI-enabled visual recognition system has been developed to be able to quickly assess the health of each fish within the 12 cages.
Fitted out for deployment even in harsh offshore environments
The vessel also has semi-submersible capability, which will allow it to harvest fish in areas experiencing strong winds and currents. Autonomous navigation capability will meanwhile enable it to select the most optimal routes, such as when avoiding areas currently experiencing or that are forecast to have severe weather conditions such as typhoons.
Despite the vessel’s large size, AI-enabled systems will handle some of the activities related to harvesting, thus making it possible for no more than four personnel to be embarked at any time.
Additional power for the onboard systems is supplied via solar panels and small wind turbine generators, thus allowing the vessel to operate with significantly reduced emissions.
Other key systems include a roller gate knife chain puller, a 100mm electric windlass, and a load monitoring system supplied by JSSK.
