Target Taiwan? Unusual Feature On Chinese Type039A Submarine Rings Alarm Bells

China's recent attempts to reconfigure its Type 039A diesel-powered submarines towards creating a more stealthy variant hint at the nation's plan to invade Taiwan, say analysts.

The new variation, which military experts call Type 039D, was revealed when pictures and posts appeared on Chinese social media platforms in May. The submarine featured a distinctively stealthy sail – an angled upper section with a ridge running along with it.

"From the designs and revision of rudder, sail and vents, limber holes, we can see the development of the subs has focused on snorkel operation [for shallow littorals operation], which is so different from the U.S. and Russian deep-diving types. To some extent, the revision and design told us that Taiwan is the top target of the Type039 subs," Macau-based military expert Antony Wong Tong told The South China Morning Post.

Beijing-based naval expert Li Jie too thinks the revision is aimed at countering U.S. attacks in case of a Taiwan contingency. According to him, the submarine is "PLA’s answer to the U.S. Navy’s modernization plan for its four operational nuclear-powered submarines – the Ohio, Los Angeles, Seawolf and Virginia."

"Once there is a Taiwan contingency, the U.S. will definitely deploy nuclear-powered subs to the Asia-Pacific region due to the long journey, but the PLA just needs to send the Type 039 subs to cope with them because it’s happening just on the doorstep,” Li said.

What makes the new variation stealthy while entering or leaving port is the angled upper section with an angled chine running along it.

"The angles created resemble the fuselages of stealth fighter planes and may reduce its radar cross-section when it is on the surface," says Defence Analyst H I Sutton in Naval News.

The South China Morning Post also quoted a collaborative study by Eric Genevelle, a French submarine encyclopedia author, and Richard W. Stirn, a former sonar technician submariner, which stated that the shape of the sail "seems to have been studied to allow better reflection of radar waves on the surface."

Besides the coating of the anechoic tiles, the dome covers, rudder, navigation lights, observation windows on the sail, and even an exhaust grid and other parts on the hull were all modified in the new variant.

According to the duo, all changes were based on designs aimed at making the diesel-powered submarines quiet.

The original Type 039A is China’s first conventional submarine which was designed mainly as an anti-ship cruise missile platform capable of hiding submerged for longer in difficult-to-access shallow coastal areas.