A previously unseen Chinese submarine featuring an unconventional low-profile design and apparently lacking a traditional sail has emerged at Jiangnan (JN) Shipyard in Shanghai, sparking intense interest among naval analysts and defense observers worldwide.
Recent satellite imagery captured on June 1 reveals the submarine moored at the shipyard, showcasing what appears to be one of the most radical departures from conventional submarine architecture undertaken by China to date. While details about the vessel remain limited, experts believe the submarine could represent a significant technological leap for the People’s Liberation Army Navy (PLAN) and may offer a glimpse into the future of underwater warfare.
The vessel’s appearance was first reported by Naval News, which noted that the submarine surfaced at the shipyard sometime in late May. Analysts are still attempting to determine the submarine’s purpose, propulsion system, and operational role, but its most striking feature is the apparent absence of a traditional sail—the vertical structure that rises from the hull of nearly every modern military submarine.
Traditional submarine sails serve multiple purposes. They house periscopes, communications equipment, radar and sensor masts, snorkels, and provide an elevated observation point when operating on the surface. Eliminating the sail therefore represents a dramatic shift in submarine design philosophy.
The exact configuration of the structure atop the newly discovered submarine remains difficult to determine from available imagery. However, analysts agree that it does not resemble the prominent sails found on conventional attack submarines.
According to undersea warfare expert H.I. Sutton, the submarine is approximately 120 meters (394 feet) long and between 10 and 11 meters (33 to 36 feet) wide. Those dimensions place it among the largest submarines currently associated with Chinese naval development.
For comparison, China’s advanced Type 093 nuclear-powered attack submarines measure roughly 108 to 110 meters in length, while the U.S. Navy’s Virginia-class attack submarines are approximately 115 meters long.
The vessel’s size has fueled speculation that it may be intended for long-range operations, specialized missions, or as part of a new generation of underwater platforms designed to operate differently from traditional submarines.
The elimination of a sail offers several potential performance advantages.
From a hydrodynamic perspective, removing a large protruding structure reduces drag and improves streamlining. A smoother hull allows water to flow more efficiently around the submarine, potentially increasing submerged speed while reducing energy consumption.
A low-profile hull can also contribute to lower acoustic signatures. Noise reduction remains one of the most important factors in submarine warfare, as modern anti-submarine systems increasingly rely on detecting minute acoustic disturbances in the water.
By minimizing turbulence and hydrodynamic resistance, a sailless design could make the submarine more difficult to detect, particularly during high-speed transit.
Such characteristics would be valuable for missions requiring rapid deployment across large distances. A submarine capable of moving quickly while remaining difficult to detect could respond to threats more effectively and operate farther from home waters.
The design may also improve maneuverability. Images suggest the submarine incorporates an X-shaped rudder arrangement at its stern, another relatively recent innovation in Chinese submarine design.
The submarine’s stern configuration appears to feature four control surfaces arranged in an X pattern rather than the traditional cross-shaped arrangement found on many older submarines.
X-form rudders have gained popularity among several modern submarine programs because they can improve maneuverability, especially in confined waters. They also provide greater control authority during low-speed operations and can enhance overall efficiency.
China first introduced this stern arrangement on a submarine in 2024, and it has become closely associated with what many analysts refer to as the Type 095 next-generation attack submarine program.
The new vessel’s adoption of the X-rudder design suggests that it may incorporate technologies intended for future Chinese submarine classes.
Reports also indicate that the submarine may utilize a shrouded propulsor, potentially a pumpjet propulsion system. Pumpjets, which enclose propeller blades within a duct, are widely regarded as quieter than traditional propellers, particularly at higher speeds.
If confirmed, such a feature would further support the idea that stealth and high-performance underwater transit were key priorities during development.
Despite its potential advantages, a sailless submarine design also presents notable operational challenges.
Traditional sails serve as mounting points for a wide range of equipment. Periscopes, communications antennas, electronic intelligence sensors, and snorkels are typically housed within these structures. Relocating such systems elsewhere in the submarine can create engineering complications and potentially limit operational flexibility.
Surface operations present another challenge.
When submarines travel on the surface, crews rely heavily on the sail for visibility and navigation. The structure provides a raised position from which personnel can observe surrounding conditions, coordinate operations, and maintain situational awareness.
Sails also support logistics activities, including vertical replenishment operations conducted by helicopters. In polar environments, reinforced sails can help submarines break through sea ice.
The apparent absence of these capabilities raises questions about how the new Chinese submarine is intended to operate.
One possibility is that the vessel has been optimized for missions conducted almost entirely underwater, reducing the importance of surface navigation. Another theory suggests that advanced sensor technologies and retractable mast systems have been integrated directly into the hull.
The newly observed submarine is not China’s first experiment with low-profile underwater designs.
In 2018, another unusual submarine emerged at the same Jiangnan Shipyard. That vessel was considerably smaller, measuring approximately 45 meters (150 feet) in length, according to previous assessments by Sutton.
Like the newly discovered submarine, the earlier craft appeared to lack a conventional sail. However, it featured a more traditional stern arrangement and an exposed propeller rather than a potential pumpjet system.
The exact purpose of that earlier submarine has never been publicly disclosed. Analysts have speculated that it served as a technology demonstrator or experimental platform intended to validate unconventional hydrodynamic concepts.
If so, the larger submarine now appearing at Jiangnan could represent the next stage of development.
The eight-year gap between the appearance of the two vessels suggests that Chinese naval engineers have spent considerable time evaluating lessons learned from the earlier platform before advancing to a much larger and potentially operational design.
Additional intrigue surrounds the submarine due to similarities between its hull shape and a concept unveiled by the state-owned China State Shipbuilding Corporation (CSSC) during the 2024 Zhuhai Airshow.
At that event, CSSC displayed a model of a large diesel-electric uncrewed underwater vehicle (UUV) featuring a similarly streamlined profile.
The proposed system was designed to perform a wide range of missions, including anti-ship attacks, mine warfare, intelligence gathering, special operations support, and acting as a mothership for smaller underwater drones.
Jiangnan Shipyard operates under CSSC, leading some observers to speculate that technological links may exist between the new submarine and the corporation’s unmanned underwater vehicle concepts.
Whether the vessel is crewed, optionally crewed, or incorporates autonomous technologies remains unknown. Most analysts currently believe the submarine is likely manned due to its size, though future hybrid operational concepts cannot be ruled out.
The emergence of the new submarine comes amid a broader modernization effort across China’s submarine force.
Over the past decade, the PLAN has dramatically expanded both the size and sophistication of its underwater fleet. New generations of attack submarines, ballistic missile submarines, and advanced conventional submarines have steadily entered service.
At the same time, Chinese shipyards continue to launch new vessels at a pace unmatched by most naval powers.
U.S. defense officials have increasingly acknowledged the rapid improvement in Chinese submarine technology. Several assessments have noted that newer Chinese designs are narrowing capability gaps that once heavily favored Western navies.
Adding to this momentum, another advanced submarine believed to be associated with the Type 095 program was reportedly launched recently at Bohai Shipyard in Huludao, northern China.
China is also believed to be developing the hybrid-powered Type 041, or Zhou-class submarine, which combines elements of conventional and nuclear propulsion technologies. The class gained attention in 2024 following reports that the first known vessel may have suffered a serious accident while under construction.
Meanwhile, Beijing’s growing emphasis on nuclear-powered submarines reflects its ambition to extend naval operations deeper into the Pacific Ocean and beyond.
Rear Adm. Mike Brookes, director of the U.S. Office of Naval Intelligence, recently described China’s submarine construction strategy as a major shift toward an increasingly nuclear-powered fleet capable of sustained global operations.
Although many questions remain unanswered, the newly observed submarine may represent more than an isolated experimental project.
Its combination of a low-profile hull, possible pumpjet propulsion, X-form stern controls, and apparent absence of a traditional sail suggests a deliberate effort to rethink submarine design for future operational requirements.
Whether intended as a high-speed interceptor, a stealth-focused attack submarine, a specialized seabed warfare platform, or a precursor to advanced autonomous systems, the vessel highlights China’s willingness to pursue unconventional solutions in pursuit of undersea superiority.
For now, analysts continue to study the limited imagery available. As additional photographs emerge and sea trials eventually begin, a clearer picture of the submarine’s capabilities may come into focus.
Until then, the mysterious vessel at Jiangnan Shipyard stands as one of the most intriguing developments in global naval technology and a potential indicator of where submarine warfare is headed in the decades ahead.
