By Kris Osborn, Warrior

Armed with wake-homing torpedoes, anti-ship missiles and naval mines, China’s ultra-quiet Type 039A attack submarine is the first “Air Independent Propulsion” (AIP) undersea attack boat operated by the People’s Liberation Army - Navy.  The boat is coated with anti-sonar anechoic tiles to reduce risk of acoustic detection, has six torpedo tubes and can launch YJ-18 anti-ship missiles. 

While non-nuclear AIP submarines such as the Type 039A are slower, less capable and less maneuverable than nuclear-powered submarines, they bring the unparalleled advantage of being able to operate for weeks without surfacing. This massively increases stealth, as oxygen is generated using fuel cells on board the submarine, so it can remain submerged for weeks at a time. This increases survivability as it makes the submarine less detectable and increases the possibilities for a successful surprise attack or clandestine undersea reconnaissance mission. 

AIP Propulsion 

An assessment of the Type 039A submarine written in “Seaforces-online” cites a US Naval Institute analysis stating that the “Yuan-class” AIP submarines are primarily intended to operate as anti-ship cruise missile platforms; as AIP submarines, they are capable of essentially “hiding” and “loitering” for long periods of time undetected, to be in an advantageous position to launch surprise attacks on surface ships from littoral waterways

Nuclear powered submarines, such as the US Navy Virginia-class, are faster and much more capable yet their reactors and cooling systems generate an acoustic signature which is more detectable than that emitted by AIP submarines. At the same time, advanced Virginia-class submarines have been upgraded in recent years with enhanced quieting technologies such as coating materials and noise reducing engine systems. 

The PLAN is estimated to operate 20-to-25 Yuan-class submarines, a fleet size which could present an area threat or undersea envelope of protection and surveillance. While the AIP Type 039A could be “quieter” than US Navy Virginia-class submarines in some respects, once detected they are likely to be far more vulnerable to being destroyed as they lack the power, speed and maneuverability of Virginia boats. 

Type 041 submarines

The PLAN is already building its next generation of attack submarines which seek to integrate nuclear propulsion with AIP at the same time. The Type 041 Zhou-class submarines are a first of its kind for China, as they are the first submarines with a nuclear reactor. This results in a hybrid propulsion system which integrates a conventional diesel-electric engine with a small, low-power nuclear reactor for AIP.  The two systems are intended to augment one another and, ideally, combine the stealth and quieting technology of AIP with the speed, power and performance of nuclear propulsion. 

Type 041 submarines are also built with an “X”-shaped stern, an innovation which adds quieting technology while increasing maneuverability and supporting a smoother, quieter glide path through the water. Interestingly, the US Navy Columbia-class nuclear armed ballistic missile submarines also operate with an X-shaped stern. 

Taiwan Strait

One area of possible concern for the Pentagon regarding Type O39A submarines may pertain to Taiwan, as the quiet, AIP-enabled submarine might be able to secretly loiter and hide in strategically vital areas where US and allied ships might wish to defend the Taiwanese coastline. Given that Taiwan is roughly 100 miles from mainland China, it seems Type 039A attack submarines might be in position to support a Chinese amphibious attack on Taiwan. 

Kris Osborn is the President of Warrior Maven – Center for Military Modernization. Osborn previously served at the Pentagon as a highly qualified expert in the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University