Three types of 927 surveillance ships entered China navy in 2018 and 2019

Photographs have circulated over the past week showing what appears to be a new Chinese ocean surveillance vessel being completed in southern China, possibly giving China a new long-range capability to detect submarines.

Three types of 927 surveillance ship entered China navy in 2018 and 2019 925 001 The type 927 (number 782) closely resembles U.S. ocean surveillance ships (Picture source: Chinese internet)

Photographs circulating on Chinese social media sites show a Type 927 twin-hulled acoustic surveillance ship berthed at the People’s Liberation Army Navy (PLAN) main South Sea Fleet base at Zhanjiang. The vessel bears the pennant number 780 and appears to be flying a naval ensign, indicating that the ship has most probably entered service. Three are known to have been built, two at the Huangpu shipyard in Guangzhou and one at the Shuangliu shipyard in Wuhan.

Type 927 vessels are twin-hulled, with a displacement of approximately 5,000 tonnes. The ships are 90 meters long and have a beam of 30 meters being completed at a shipyard in Huangpu near Hong Kong that has built SWATH designs for the Chinese navy before. SWATH vessels are both extremely stable and extremely quiet, especially when outfitted with electric motors for propulsion. Their stability and quiet make them especially useful for hydrographic surveying and research utilizing sonar and other sensitive acoustic equipment, and for locating submarines.

While the photographs do not yet show any obvious equipment such as reels for towed sonar arrays, the vessel is almost certainly intended to support Chinese anti-submarine warfare operations to detect and track submarines. The Chinese vessel bears an unmistakable resemblance to U.S. Navy Ocean Surveillance Ships, which are equipped with advanced sonar arrays to detect and track submarines at great ranges. These ships trail sensitive listening equipment on long cables that can pick up the sound of submarines travelling underwater and track their movement. Some can augment their passive listening arrays with low-frequency active arrays that send sound waves into the water to bounce off submerged submarine hulls to reveal their location.