In a recent US Naval War College report, concerns have been raised about the secrecy surrounding China’s submarine production and its growing cooperation with Russia. This collaboration could potentially accelerate China’s submarine manufacturing capabilities and shed light on Beijing’s closely guarded submarine prowess.

With technical details about submarine production classified in most countries, China takes secrecy to a whole new level, making it challenging to assess its undersea warfare systems.

China’s Culture of Extreme Secrecy

The China Maritime Studies Institute’s latest report highlights the culture of extreme secrecy in China, which extends even to less critical aspects of submarine production. This opacity is characterized by a lack of public budgets, opaque procurement processes, a monopolistic approach to procurement, and a hidden build schedule.

As a result, China’s submarine procurement remains more obscure than that of most other nations.

One of the key challenges in assessing Chinese submarine capabilities is the discovery of new submarine types only after their construction is complete, often through satellite imagery or accidental footage. This lack of transparency makes it difficult to gauge China’s undersea warfare systems’ true capabilities.

Dr. Sarah Kirchberger, a professor at Kiel University and a former naval analyst with German shipbuilder TKMS, has tackled in the report that China attempts to balance preserving technical secrets of submarine production and showcasing military breakthroughs.

Not to mention how Beijing frequently uses disinformation as a tool in information warfare to create ambiguity about its advanced arms programs.

Foreign Subsystem Suppliers and Export Customers: A Valuable Perspective

One significant source of information about China’s undersea platforms comes from its submarine export customers in countries like Thailand, Pakistan, and Bangladesh.

Information from foreign subsystem suppliers and experiences reported by these customers can provide valuable insights into the actual capabilities of Chinese undersea warfare systems.

A notable case study emerges from China’s submarine deal with Thailand. In 2022, Beijing faced a setback in its submarine deal with Bangkok due to its inability to manufacture a marine diesel engine for Song-class and Yuan-class submarines.

These submarines rely on imported marine diesel engines produced under license by the German engine maker MTU. The MTU 396 SE84 diesel engine powers all the Song-class (Type 039) and Yuan-class (Type 039A) submarines in China’s fleet.

Song-class submarine
Type 039, NATO reporting name Song, submarine (Image source: Wikimedia Commons)

China’s contract to supply one S26T Yuan-class submarine to Thailand in 2023 fell apart a year prior when it became clear that the German government would not grant an export license for the MTU engine. In response, China offered its indigenous CHD620 diesel engine, which Thailand was still hesitant to accept as of April 2023.

Cases like this highlight a “puzzling bottleneck” in China’s submarine production.

A German submarine design expert interviewed for the report considers the engine a relatively old technology that is not too complicated to master and poses manageable technical risks. The concerns may be related to the exhaust back pressure system for discharging diesel exhaust below the surface when operating at snorkeling depth, which requires a unique charge air system to prevent water from entering the engine.

China has also supplied submarines to Myanmar and is exploring opportunities to sell its undersea platforms to other countries. However, China’s submarine industrial base faces challenges, particularly in propulsion and stealth technologies.

China’s Submarine Industrial Base: Prospects with Russia

The report mentions that closer ties with Russia could help China overcome these technological limitations.

While China excels in some areas of submarine production, such as conventional Air-independent propulsion (AIP) propulsion, it lags behind in quieting and nuclear propulsion. On the other hand, post-Ukraine war, Russia’s design bureaus and industries could face a brain drain toward China due to a lack of funding.

“Closer ties with Russia could provide opportunities for China to overcome these enduring technological limitations by exploiting political and economic levers to gain access to Russia’s remaining undersea technology secrets,” the report reads.

Accordingly, the report proposes potential synergies between Russia and China, where Russia could provide essential know-how on submarine acoustic signature quieting, nuclear propulsion design, and hydrodynamic hull design. In return, China’s modernized shipyards could offer the industrial capacity to build submarines at a rapid pace, taking advantage of economies of scale.

A noteworthy development in the context of Russian-Chinese cooperation is the visit of Admiral Nikolai Yevmenov, the Commander-in-chief of the Russian Navy, to a naval shipyard in Shanghai in July 2023. This visit sparked speculation about Russian interest in ordering hulls from Chinese shipyards to replenish its naval forces.

Another area of potential cooperation between Russia and China concerns nuclear fuel deliveries. In December 2022, Russia’s Rosatom Corporation supplied highly enriched uranium to China’s fast-breeder reactor CFR-600 on Changbiao Island.

This partnership could potentially be used as fuel for future nuclear-powered submarines, further deepening cooperation in submarine technology.

The Russian-Chinese Nexus: A Glimpse into the Future

The report overall highlights the secrecy surrounding China’s submarine production and its efforts to balance technical secrets with showcasing military prowess.

Growing ties with Russia could provide opportunities for China to overcome its technological limitations in submarine manufacturing. While these two countries strengthen their collaboration, the trajectory of submarine production and safeguarding technology secrets remain uncertain.

Nevertheless, the potential for substantial partnership is evident.