Type 904

dive tender A diving support vessel is a ship that is used as a floating base for professional diving projects. Basic requirements are the ability to keep station accurately and reliably throughout a diving operation, often in close proximity to drilling or ...

is a class of Chinese dive tender designed the People’s Republic of China (PRC) for the

People's Liberation Army Navy The People's Liberation Army Navy (PLAN; ), also known as the People's Navy, Chinese Navy, or PLA Navy, is the maritime service branch of the People's Liberation Army. The PLAN traces its lineage to naval units fighting during the Chinese ...

(PLAN), and the late models Type 904I and Type 904II have received the

NATO reporting name NATO reporting names are code names for military equipment from Russia, China, and historically, the Eastern Bloc (Soviet Union and other nations of the Warsaw Pact). They provide unambiguous and easily understood English words in a uniform manne ...

''Yanqian'',(研潜 in Chinese), meaning Research Diving. In addition to perform diving support missions, Type 904 I and II ships are also general purpose

research vessel A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicated ...

s (AGE)frequently tasked to perform various scientific research works.

Type 904

Type 904 shares the same hull of Type 991II Youdian class cable layer, but the original design encountered difficulty when the development of domestic Chinese

saturation diving Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers working ...

support system stalled. Decision was made to import such system from abroad, with French system eventually selected. Consequently, the original Type 904 never went into production because the design had to be modified to accommodate the foreign saturation diving support system, and the modified design is designated as Type 904I.

Type 904I

Type 904I is a slight variation of earlier Type 904 design with design change to incorporate machinery to handle foreign diver support system. The crane at the stern is capable of lifting 13-ton weight. Equipped with French SM358-Z dive support system, Type 904I can support divers up to a depth of two hundred meters. Designed by the 708th Institute of China State Shipbuilding Corporation, which is also more commonly known as China Shipbuilding and Oceanic Engineering Design Academy
中国船舶及海洋工程设计研究
) nowadays, Type 904I is capable of normal operations in sea state 3 and wind scale 5. Type 904I is named as Kan-Cha (Kancha, 勘查) I, meaning Exploration in Chinese. Specification: *Length (m): 69.9 *Width (m): 10.5 *Draft (m): 3.64 *Displacement (t): 1354.8 *Speed (kt): 13.5 *Propulsion: 2

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s @ 1100 hp (809 kW)

Type 904II

Type 904II is a slight upgrade of earlier Type 904I with some improvements. Designed by the same institute and built by the same shipyard, Type 904II can operate in the same sea state Type 904I does. Euipped with French SM360 diver support system, Type 904II can support diver to a depth of three hundred meters. Specification:Type 904II
/ref> *Length (m): 71.55 *Waterline length (m): 66 * Length between perpendiculars (m): 63 *Width (m):10.5 *Depth (m): 5.2 *Draft (m): 3.6 *Displacement (t): 1327 *Speed (kt): 14 *Propulsion: 2

s @ 1100 jp (809 kW)

Ships

Original names of these ships listed in the table below might have been changed due to the new naming conventions of PLAN.

References

{{Ship classes of the Chinese Navy, state=uncollapsed Auxiliary ships of the People's Liberation Army Navy Auxiliary tender classes