Type 904 dive tender is a class of Chinese dive tender designed the

People’s Republic of China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

(PRC) for the People's Liberation Army Navy (PLAN), and the late models Type 904I and Type 904II have received the NATO reporting name ''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 The China State Shipbuilding Corporation (CSSC) is a Chinese shipbuilding conglomerate. Description CSSC is one of the top 10 defence groups in China. It consists of various shipyards, equipment manufacturers, research institutes and shipbu ...

, 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-ca ...

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 Length between perpendiculars (often abbreviated as p/p, p.p., pp, LPP, LBP or Length BPP) is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the ster ...

(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