Recently, the first deep-sea semi-submersible aquaculture platform in Zhejiang Province, “Donghai I” was successfully put into the Xiangshan waters to start the construction and installation work at sea, this mobile aquaculture platform formally opened the prelude for the development of deep-sea aquaculture.
“Donghai I” aquaculture platform, was built by Ningbo Huanhai Heavy Industries (Huanhai Heavy Industries), developed by Guangzhou Institute of Energy Coversion, Chinese Academy of Sciences (CAS) and designed by Zhuhai Gesheng Technology, a subsidiary of Zhuhai Ocean Group.
The platform is 82 meters long, 32 meters wide, 22 meters high, with a working draft of 13 meters and a culture water body of about 36,000 cubic meters. It is the first set of semi-submersible intelligent aquaculture platform for deep-sea in Zhejiang Province, and is also the first semi-submersible aquaculture platform that Zhuhai Gesheng Technology has applied outside the province.After put into production, it is expected to produce 900,000 tails of high-quality seafood annually, with an output of 400 tons and an output value of about 40 million yuan, making it a veritable “granary on the sea”.
The platform has a number of advantages such as good stability, strong wind and wave resistance, high degree of intelligence, convenient operation at sea, etc. The platform is a highlight project of the transformation and upgrading of Zhejiang Province’s offshore traditional aquaculture to deep-sea aquaculture equipment, mechanization and informationization, and is a concrete initiative to vigorously develop the “new quality productivity” of marine fisheries.
The biggest challenge facing Zhejiang’s deep-sea aquaculture is frequent typhoons. The Donghai I platform will be fixed to the sea floor with eight 400-meter-long anchor chains, and will undergo sea sinking and floating tests. After passing the inspection by the classification society, it can carry out the breeding test, and the whole installation takes 3 to 5 days.
In response to the actual situation of strong ocean currents and frequent typhoons in the East China Sea, the platform uses ballast water tanks to adjust the platform’s center of gravity position, buoyancy and stability, with a lifting and lowering function of more than 10 meters, and 8 anchor chains to ensure that the platform’s position is not shifted. It can withstand the test of 17-level super typhoon, fully guaranteeing the safety of the platform in the state of aquaculture production.
“Donghai I” also adopts ultra-high molecular weight polyethylene (UHMWPE) double-layer mesh material, the breaking strength of the mesh made of UHMWPE is 8 times higher than that of steel ropes under its own weight, which effectively prevents the fish from escaping due to the breakage of the mesh.