It is well known that the Chinese Navy has numerical supremacy over the navies of other countries. However, a recently released report says that after five decades since it inducted its first nuclear-powered conventionally armed submarine (SSN), the People’s Liberation Army – Navy (PLA-N) is on the verge of producing “world-class” nuclear submarines with its propulsion, quieting, sensors and weapons capabilities approaching that of Russian Akula -I class SSN.
Acoustic stealth is one of the salient attributes of modern submarines. The quietness of the design is seldom revealed, but the assumption can be safely made that Chinese submarines are increasingly becoming stealthier.
The report released by the US Naval War College assesses that this giant leap in technology will have “profound implications” for US undersea security.
China began its nuclear submarine program in July 1958 when Mao Zedong and the Central Military Commission (CMC) authorized the “09 Project.” As China lacked the required industrial capability, it persisted in seeking help from the erstwhile USSR. After being rebuffed several times, Mao issued the decree that China would proceed on a path of self-reliance in developing nuclear submarines.
After years of development, the first nuclear submarine, Type 091 (Han-class), was commissioned on August 1, 1974. It was in the mid-1990s that China was able to obtain submarines from a cash-strapped Russia.
The process of “imitative innovation” took some time as Chinese engineers learned how to duplicate and then improve the technologies they had purchased. But the time-consuming process meant that “the existing Type 093 and 094 submarine hulls were just too small to take full advantage of the technology that had been developed”.
The Type 091 SSN was the first-generation nuclear-powered submarine of the PLA-N. The second-generation submarines in the PLA-N fleet are the Type 093A Shang-II class. These 7,000-tonne nuclear-powered boats make up most of the Chinese Navy’s fleet. They are roughly the size of the Royal Navy’s Astute class submarines.
The Shang-class submarines are built by China Shipbuilding Industry (CSIC) at its Bohai Shipyard in Huludao, Liaoning Province, China. A total of six Shang-class submarines, including Shang I class SSNs (Type 093), Shang II class SSNs (Type 093A), and Shang III class SSNs (Type 093B), are in service with the PLAN. The Type 093A and Type 093B SSNs are improved versions of the Type 093 submarine.
It has been speculated that China may be building a variant with a vertical launch system (VLS) for land-attack cruise missiles. Before the mighty third-generation, Type-95 Sui Class enters service, a cruise missile variant of the Shang missile helps in proving the technology.
In early 2023, satellite images revealed that China launched the 8th Type 093 Shang-class SSNs between 13 and 18 January 2023. The land attack capability would help them to engage targets on land, much like Russian submarines have done in Ukraine.
Nearly 50 years after China commissioned the Type 091 SSN, it has designed and developed Type 095 (Tang Class attack Submarine) that has “the potential to approach the propulsion, quieting, sensors and weapons capabilities of Russia’s improved Akula I 30 class SSN.”
“The Type 095 will likely be equipped with a pump jet propulsor, a free-floating horizontal raft, a hybrid propulsion system, and 12-18 vertical launch system tubes able to accommodate anti-ship and land-attack cruise missiles,” the report tracing China’s maritime history notes.
“The Type 096 (ballistic missile submarine) will also see significant improvements over its predecessors and could compare favorably to Russia’s Dolgorukiy class SSBN in the areas of propulsion, sensors, and weapons, but more like the Improved Akula I in terms of quieting,” the report notes. “Should China successfully make the jump in capabilities from the current Victor III-like platform (Type 093A Version 3) to an Improved Akula I-like platform, the implications for the US and its Indo-Pacific allies would be profound,” the report warned.
Building Quieter & Stealthier Submarines
The quietness of a submarine gives its stealth. One of the major reasons for noisier sub is the propeller blades that cause an underwater phenomenon called cavitation, where bubbles form along the blade edges and cause underwater noise.
Another contributing factor to a nuclear-powered submarine’s noise is the reactor core’s coolant pumps.
All the Chinese submarines have, so far, used propellers as propulsors as against many US and NATO submarines (including the US Navy’s Virginia class and the Royal Navy’s Astute class, which use pump-jet propulsors. The submarines with pump-jet can evade the enemy’s listening devices more dexterously and sneak up on its target.
The US Navy’s Office of Naval Intelligence estimates the Shang class is noisier than the Soviet Victor III-class submarines developed in the late 1960s, placing them at least two generations behind their American counterparts in terms of stealth.
The first two versions of Type 093 Chinese nuclear submarines had reverse-engineered Russian noise reduction technology, specifically the exterior anechoic coating and pneumatic sound isolation mounts.
On January 12, 2018, a Type 093A submarine surfaced in the contiguous zone (within 24 nautical miles) off the disputed Senkaku/Diaoyu Islands. A Japanese Maritime Self-Defense Force destroyer and P-3C maritime patrol aircraft had been tracking the Chinese submarine since mid-morning on January 10.
The best estimate of the submarine’s speed was around 5-7 knots, which means the narrowband machinery tonals were the dominant acoustic feature. If the Japanese Defense Ministry report is accurate, then the Type 093A Version 2 submarine was not particularly hard to track with passive systems, indicating a relatively noisy boat.
Observers of the Chinese Navy suspect that the new 93 B might have this technology. A pump jet propulsor would be a substantial upgrade for the Shangs without investing in a new hull.
The Type 095 and Type 096 B are likely to be equipped with pump-jet propulsion likely to be tested in the lead Type 093 B submarine.
According to the Naval War College report, the third-generation PLAN nuclear submarines could have “a hybrid propulsion system.” A combination of turbo-reduction for high-speed operations and a turbo-electric drive for quiet, slow-speed propulsion with a maximum speed of 8-10 knots, depending on the submarine design (SSGN vs SSBN).
This is reportedly the same propulsion plant arrangement that the Russians have put into the Project 955/955A Borey class SSBNs.
Long Range Strike
The capability to launch land-attack cruise missiles with a range of 1500 km has been on the PLAN’s wish list. When cruise missiles first went to sea, submarines launched them from torpedo tubes.
Most of China’s current submarines still deploy cruise missiles like this. More modern submarines, including the Virginia class, have shifted cruise missiles to separate vertical launch silos, sparing its torpedo tubes for firing torpedoes.
The Shang class submarines lacked vertical launch missile silos. The Type 93B is also not believed to have this capability. However, the third-generation submarines are expected to carry land attack cruise missiles to strike at the heart of the enemy’s territory.
The US and Russia have used submarine-launched cruise missiles to strike targets in Sudan, Yugoslavia, Afghanistan, Yemen, Libya, Iran, Syria, and Ukraine. China could use its submarines to attack targets in Taiwan, Japan, and even the US.
- Ritu Sharma has been a journalist for over a decade, writing on defense, foreign affairs, and nuclear technology.
- She can be reached at ritu.sharma (at) mail.com