Type 041 submarine

The  Type 041 submarine (NATO code name Yuan class) is a class of diesel-electric submarine in China's People's Liberation Army Navy. This class was first launched at Wuhan Shipyard and is the successor of the Type 039. The Chinese type is 039A, based on the Type 039 but ultimately having very little resemblance to it. So the western media call it Type 041 in early reports.

Design
The Type 041 inherits the tail design of the Type 039 (NATO codename: Song class) with four diving planes and a single large shaft. The teardrop shaped hull and large sail suggest heavy Kilo influence. The teardrop shape also suggests a pressurized double hull design inherited from the Kilo. A pair of foreplanes are positioned in the middle of the sail. The submarine is equipped with indigenously developed cabin-raft (shock absorbers) system that helped to reduce noise level by over 35dB. Additionally, the submarine is covered with rubber anti-sonar protection tiles to reduce the risk of detection. A new improved "A" variant was also launched.

Weapons
The Type 041 has six 533 mm torpedo tubes. These can be used to launch indigenous as well as Russian-made torpedoes. The general designer of the torpedo and missile launching system is Mr. Sun Zhuguo (孙柱国, 1937-). The Type 041 is also believed to be capable of launching YJ-8X (C-80X) series anti-ship missiles. The missile uses inertial + terminal active radar guidance. It carries a 165 kg time-delayed semi-armour-piercing high-explosive warhead, with a maximum range of 80~120 km and speed of Mach 0.9.

The Type 041 is also capable of firing the CY-1 ASW missile under water, but the status of the missile is in question because nothing is heard about its production. The CY-1 ASW missile has a maximum range of 18 km (10 nm), and when using A244 or Mark 46 torpedo as a payload.

This class is designed to replace the aging Romeo and Ming Class SSKs that previously formed the backbone of the PLAN conventional submarine force. At least seven boats have been commissioned as of 2013 by the PLAN.

Sensors
China was known to have imported the Thales TSM 2233 ELEDONE / DSUV-22 and Thales TSM 2255 / DUUX-5 from France during the 1980s and early 1990s. It also has access to a wide range of modern Russian sonar systems (MG-519 MOUSE ROAR, MGK-500 SHARK GILL) through its purchase of the Kilo Class. Comparable systems are expected to be installed for the Type 041.

The Type 041 is likely to be fitted with a comparable surface/air search radar similar to the MRK-50 SNOOP TRAY, a commercial navigation radar like a Furuno unit observed on a number of SONG class and ESM system is comparable to the Type 921-A.

Propulsion
Contrary to many erroneous claims circulated on the internet by domestic Chinese military enthusiasts, the rumored pump-jet propulsion system is not used on this submarine, because that system is still under development. According to the official academic journals published in China, compared to the seven-bladed propeller currently used, the prototype of the indigenously-developed pump-jet can reduce noise level by 7 dB at 6 knots or 10 - 12 dB at 11 knots. But the system still needs further testing, and the current rumor that the pump-jet is planned for later units of this class is highly unlikely. Diesel engines are used for conventional propulsion; this class is the first boat in the Chinese inventory that can achieve full electrical propulsion, which greatly reduces radiation noise. The same all-electric propulsion design is also modified for use on the Chinese navy's Type 093 submarine and Type 094 submarine. The general designer of the all-electric propulsion systems used in these boats is Professor Ma Weiming (马伟明) of China's Naval Engineering University. (Ma, born in Yangzhong in 1960, obtained his Ph.D. from Tsinghua University in 1996.)

According to the Chinese newspaper Science and Technology Daily (科技日报), this 041 class is equipped with an air-independent propulsion system developed by the 711th Research Institute of the China Shipbuilding Heavy Industry Group Corp. (中国船舶重工集团公司第七一一研究所), referred as a "specialized engine" in official Chinese sources. The 711th Institute was founded in April 1963, but it was not until more than a decade later, in 1975, that it ventured into the field of air-independent propulsion systems by establishing an office for a "specialized engine," setting up a team of about a dozen researchers. By June 1996 that team had developed into the "specialized engine engineering research center"; by 2008 there were more than a hundred researchers. In 1998, the first experimental sample was built and a decade later and after a dozen technological breakthroughs, a wide range of matured versions became commercially available and the newest diesel-electric submarine in Chinese navy became the first customer. Although the official Chinese source had not mentioned the exact class of the submarine, it is generally accepted that the class is no other than Type 041 Yuan class, since it is the newest conventional powered submarine in the Chinese navy. The engine is built by Shanghai Qiyao Propulsion Technology Ltd. (上海齐耀动力技术有限公司), a wholly owned subsidiary of the 711th Institute (中国船舶重工集团公司第七一一研究所).

However, the Chinese source failed to mention the exact type of air-independent propulsion system had been installed, but the developer offered a selection ranging from 20 kW to 100 kW (rate for single unit). Recent rumors stated that the boat utilize a Stirling cycle engine, but this cannot be confirmed. It is also unclear if the incorporation of air-independent propulsion system has become the standard or just for evaluation purposes. Since the air-independent propulsion systems onboard western submarines usually rate at 150 kW to 300 kW, so it is safe to assume that similar systems onboard Chinese submarines would also be consisted of at least two units just like its western counterpart.

S20
At IDEX-2013, China revealed a scaled-down version of Type 041 submarine designated as S20, specially intended for export. The main difference between S20 and Type 041 is that the AIP system on the original Type 041 is deleted, but can be available and easily integrated due to modular design of S20, if potential customers choose to purchase AIP systems separately. Due to its modular design, a variety of sensors and weapons can also be easily adopted up on customers' requests. Specifications of S20:
 * Structure: double hulled
 * Length: 66 meter
 * Beam: 8 meter
 * Draft: 8.2 meter
 * Surface displacement: 1850 tons
 * Submerged displacement: 2300 tons
 * Maximum speed: 18 knots
 * Cruise speed: 16 knots
 * Range: 8000 nm @ 16 kts
 * Endurance: 60 days
 * Crew: 38 total
 * Maximum depth: 300 meters