There has been intense Western media reporting alleging that a novel Chinese submarine prototype destined for the People's Liberation Army Navy (PLAN) sank whilst under construction at the Wuhan Shuangliu shipyard on the Yangtze river four months ago.

Thomas Shugart, an analyst at the Centre for a New American Security and a former US Navy submariner, first noticed in satellite imagery an unusual collection of four crane barges around what appeared to be a submarine either fully or partially submerged. The Wall Street Journal was the first to publish a story on this speculative event on September 26, with many other outlets rapidly jumping on the story.

The hybrid submarine in question was a first-of-class Type 041, also known as the Zhou class, which state-owned China State Shipbuilding Corporation was building in Wuhan. Satellite images showed crane barges were present from at least 12-17 June, as well as a boom net to capture oil spills. Such cranes would be necessary to lift a submarine off a riverbed. By the first week of July, the barges were gone, the submarine presumably salvaged, and activity seemed to have returned to normal. What attracted the most attention were allegations that this submarine featured a nuclear reactor. Importantly, there has been no release of radiation nor any evidence of a nuclear emergency response, so this was certainly not a Chernobyl-type incident.

An unnamed Pentagon spokesperson quoted by The Wall Street Journal article said the Type 041 is a "new class of nuclear submarine that is similar in size to navy conventionally powered submarines, but with a small nuclear reactor". They added, "As such, we do not know if the submarine reactor was fueled at the time of incident, or if it is going to be relocated to a known nuclear-certified facility for its initial fueling, such as Huludao shipyard, which has built all previous navy nuclear submarine classes."

The American spokesperson provocatively noted: "It's not surprising that the PLA Navy would try to conceal the fact that their new first-in-class nuclear-powered attack submarine sank pier-side."

China has indeed been silent on the incident, neither confirming nor denying it. When asked about the potential incident, a Chinese Foreign Ministry spokesperson said at a Beijing press conference on 27 September that he was unfamiliar with the topic. A Chinese embassy spokesperson in Washington also said, "We are not familiar with the situation you mentioned and currently have no information to provide."

Considerable caution is needed when discussing Chinese military programs, especially when China refuses to divulge information. It can be dangerous to speculate or make assertions based on fragmentary evidence or episodes. Indeed, the assertion by some media that this was a nuclear-powered submarine was a mischaracterization. There is no doubt that China has been developing the Type 041 SSP(N) type, as its existence is noted in the latest order of battle in the reputable Modern Chinese Maritime Forces listing. Authored by Manfred Meyer, this publication is the most comprehensive, unclassified, open-source Chinese data available on the PLAN. This document described the Zhou class as "a testbed for air-independent propulsion (AIP) with micro-nuclear reactor". The submarine has a tentative displacement of 4,000 tons and is 84m long.

Furthermore, there was previous evidence that China was developing such technology. Slides from a Chinese presentation by retired Rear Admiral Zhao Dengping of the PLAN in 2017 hinted that China was pursuing such a concept. Richard D. Fisher Jr., an American analyst with the International Assessment and Strategy Center, analyzed this information revealed at that time. He assessed: "Zhao...revealed the PLAN may be working on a novel low-power, low-pressure auxiliary nuclear power plant for electricity generation for fitting into conventional submarine designs, possibly succeeding the PLAN's current Stirling engine-based AIP systems."

Fisher elaborated: "One slide seems to suggest that the PLAN will continue to build smaller submarines around the size of current conventional powered designs, but that they will be modified to carry the new nuclear auxiliary power plant to give them endurance advantages of nuclear power."

Today, the US Navy produces only nuclear-powered submarines, whereas China has pursued the twin prongs of conventional and nuclear propulsion. Now it seems to be combining the best of both design types by developing a hybrid that is principally a diesel-electric boat, but which adds a nuclear reactor to greatly increase its submerged range and endurance. Such a vessel type is important for China, as it typically operates its submarines in the shallow waters that predominate in the East China Sea, South China Sea and Taiwan Strait.

The PLAN currently has six nuclear-powered ballistic missile submarines (SSBN) and six nuclear-powered attack submarines (SSN). These large submarines are manufactured at Huludao shipyard, which has expanded the past few years, a point that underscores how the PLAN expects to enlarge its dedicated fleet of SSNs and SSBNs. Indeed, the appearance of the Type 041 is not evidence of Wuhan moving into the business of building nuclear-powered submarines in competition with, or in collaboration with, Huludao. It is likely that, after construction, the submarine would move to Huludao to be fueled. Nonetheless, it is unclear how or when a nuclear power plant and fuel would be installed in the Zhou class, for it is not a simple matter to drop reactors and fuel rods into an assembled pressure hull.

China is not the first nation to go in this direction either. The Soviet Union tested the concept on the Juliett-class diesel-electric submarine K-68 in the 1980s, where it used a 600kW VAU-6 nuclear power plant within a hermitic pod to greatly improve the boat's submerged range. Russia followed up with something similar with its secretive 1,600-tonne Losharik nuclear-powered submarine that features a 15MW E-17 nuclear reactor. A fire broke out aboard the submerged boat on 1 July 2019, resulting in 14 fatalities.

Returning to the Type 041, rumours of this new class first emerged in Chinese media late last year, at which point it was tentatively described as an improved version of the Type 039 Yuan class, with two such AIP-equipped boats supposedly in production at Wuhan. However, hints of the inclusion of nuclear power in this class really gained momentum when Du Wenlong, a PLA senior colonel who has turned into a state television commentator, wrote in May, "Some people say that China is making a 'Type 041' small nuclear submarine." He advocated such a design, saying, "If you want to achieve qualitative transcendence, you have to make a small underwater nuclear submarine..."

Du further added, "So I personally feel that this is a particularly good idea, unifying the 'conventional' and 'nuclear', using nuclear power and then using the tonnage and displacement of conventional submarines. In this way, in waters of 200-300 meters, its deterrent capability to surrounding conventional submarines will be further enhanced ... I personally support '041', whether it is a name given by everyone or not. With such new equipment, our underwater endurance and strike capability will be multiplied."

Discussing China's technological acumen, the China Maritime Studies Institute, part of the US Naval War College, gave this assessment of Chinese submarine efforts in May 2023: "In recent years, China has seen tremendous expansion in the shipbuilding facilities that can produce both conventional- and nuclear-powered submarines. Nevertheless, China's technological progress in submarine construction has been uneven, with enduring weaknesses in propulsion and quieting. To compensate, China has exploited its partnership with Russia to obtain access to cutting-edge submarine-related technologies."

It continued: "China operates the world's largest fleet of air-independent power submarines ... China is investing in research and has dedicated resources to produce numerous experimental subs. Through 'imitative innovation', China has modified proven Russian submarine technology in nuclear reactors, sound isolation mounts, towed arrays and torpedoes to meet its needs." China is paranoid about keeping military secrets, and Type 039 Yuan-class submarines, for instance, were only spotted in satellite imagery in July 2004 without any announcement by government or military officials. The same is presumably true of the Type 041, for China never indicates when a new class has appeared, or how many are to be produced. China is assumed to be developing lithium-ion batteries for its conventional submarines too, a technology that both Japan and South Korea are utilizing on their latest boats.

The unknown Pentagon expert quoted by The Wall Street Journal said, "In addition to the obvious questions about training standards and equipment quality, the incident raises deeper questions about the PLA's internal accountability and oversight of China's defence industry - which has long been plagued by corruption."

However, commentators must take care not to swing between either outright disparagement of the PLA's technical progress, nor magnifying China as a technological wunderkind. The truth usually rests somewhere between these two extremes. Therefore, it should not be concluded, as a US defence spokesperson suggested, that Chinese technology is seriously suspect or that the PLA's modernization is in jeopardy by this suspected accident.

Similar media frenzy occurred in January when Bloomberg carried a story citing US defence officials who alleged that the PLA Rocket Force's missiles and capability were being adversely affected by corruption, including missile silo lids that did not properly function. Or take reports that appeared in August 2023, alleging that a Chinese Type 093 SSN had sunk in the Taiwan Strait; such an allegation was soon scotched through lack of evidence.

The USA brings its own biases and it is happy to insinuate major problems in the PLA. Regardless, the fact is that China has achieved numerous technical breakthroughs, as illustrated by its successful launch of a DF-31AG intercontinental ballistic missile on September 25, which flew 12,000km across the Pacific before splashing down near French Polynesia.

Dr. Andrew Erickson, Professor of Strategy at the US Naval War College, level-headedly commented that this latest submarine incident "is a specific speed bump from pushing an exotic program as part of a demanding comprehensive approach, not an overall showstopper or reflecting prohibitive incompetence". China is likely to produce a very limited number of this type initially to test the configuration.

The Zhou class also features X-form rudders, something visible in satellite images. This is a first for Chinese submarines, since they traditionally have a cruciform rudder shape. An X-form rudder is considered better for agility, particularly in shallow waters. In the same 2017 presentation quoted earlier, Zhao Dengping also spoke of a new-type 7,000-ton SSN with a new propulsion plant, new weapon systems and electronics, plus a 12-cell vertical-launch system (VLS) for missiles. Such a vessel has not yet appeared, but the mention of VLS is significant. The newer Zhou-class boat that sank had a significantly elongated hull behind the sail---this is likely an indication that it has a VLS installed. Meanwhile, the hull's forward section appears similar to the regular Yuan class. This longer hull is most significant, for Chinese diesel-electric submarines like the Type 039 currently do not possess such missile launch systems.

A VLS would allow weapons like the YJ-18 anti-ship missile or CJ-10 land-attack missile to be easily launched by the Type 041, or even anti-ship ballistic missiles. The extra length is sufficient to fit a VLS section containing perhaps 4-8 missiles.

Combined with a longer submerged endurance thanks to a nuclear reactor, the addition of a VLS on a conventional submarine represents a significant step forward for the PLAN if this new Zhou class begins entering service. This would make it one of the world's most potent conventional submarines. Indeed, a preponderance of such stealthy boats would put American and allied bases and ships at greater risk, since they could get closer and launch more effective missiles.

(With Agency Inputs)