China Reportedly Tests Trimaran Submarine With 16 or More Missile Tubes

China is testing a new type of trimaran-hulled submarine built to carry a large missile load, according to an analysis published Wednesday by Naval News. The vessel is reportedly undergoing trials in Huludao, on the Bohai Sea.

The roughly 65-meter vessel was built in Guangzhou and moved north through the port of Dalian earlier this year. A Vantor satellite image taken May 12 shows it at Dalian, according to Naval News. It has no official designation or Western reporting name.

First Spotted a Year Ago

Naval News analyst H I Sutton first reported the vessel on Oct. 29, 2025. It was then under construction at the Huangpu shipyard in Guangzhou, mostly hidden under tarpaulin.

Sutton judged it likely uncrewed or minimally crewed and called a semi-submersible arsenal ship the leading, unconfirmed theory. He noted that clear images of the forward deck, where missile silos would be, had not yet been seen.

Missiles That Rise to Fire

The central hull appears to hold two horizontal hangars with missile tubes arranged in circular clusters. At least eight tubes are visible. The total is estimated at 16 to 18 if both hangars are identical.

To fire, the vessel would have to surface, open the hangar doors and raise the tubes to a vertical or near-vertical position.

The missile type is unconfirmed. Analysts say the tubes likely hold anti-ship or land-attack missiles designed for surface launch. The hypersonic YJ-20, associated with Type 055 cruisers, is considered a contender. China test-fired a long-range missile in the Pacific earlier this year.

Likely Uncrewed

The trimaran hull has outriggers near the stern, a snorkel that lets diesel engines run while submerged, and ducted propellers on the outriggers. Naval News cites a design estimate of about 900 tonnes submerged.

The weapons hangars take up so much volume that the interior is believed to be too cramped for a crew. The bridge on the fin is likely used only by a pilot entering and leaving port.

A Cold War Precedent

Ship designer Rachel Pawling, quoted by Naval News, likens the concept to the Soviet Juliett-class cruise missile submarines of the Cold War. Those diesel boats had to surface to fire their anti-ship missiles and could pop up to attack high-value warships from unexpected directions.

The Juliett carried four SS-N-3 Shaddock missiles. The Chinese vessel would carry far more, with longer-range weapons that depend on external targeting data.

No Official Word

China has not publicly explained the vessel. Naval News says it has not been reported or named in Chinese media, and GlobalSecurity noted as of September that neither the PLA Navy nor the defense ministry had commented on it.

The ports where it has been seen do not match those tied to China's large uncrewed surface vessel or extra-large uncrewed submarine programs, suggesting a separate effort. The findings rely on open-source intelligence, mainly commercial satellite imagery.

The vessel appears as Beijing continues its military build-up in the Paracels, where it has also created a man-made island for its largest base.