China bolstering its submarine ocean surveillance capabilities

China’s submarine ocean surveillance capabilities are set to increase further as satellite images show that two more Type 927 (Dongjian)-class acoustic surveillance vessels for the People’s Liberation Army Navy (PLAN) are nearing completion and that a similar but larger vessel has been constructed at the Bohai shipyard in Huludao.

The first three Type 927 ships were launched between mid-2017 and early 2018, with satellite imagery indicating that two of those are now in service with the South Sea Fleet and appear to be based in Zhanjiang. The third has been allocated to the East Sea Fleet and based at Dinghai.

Satellite imagery also shows that a fourth Type 927 was constructed at the Huangpu shipyard in Guangzhou and launched between August and November 2020. A fifth vessel has been built at the Wuchang-Shuangliu shipyard and was launched between August 2020 and January this year. Fitting out these vessels and conducting post-build trials is unlikely to take longer than a few months, so both ships are likely to be in service by the end of the year.

The Type 927 adopts a small waterplane area twin hull (SWATH) design and is broadly similar in appearance to the US Navy’s USNS Impeccable (T-AGOS 23): a Surveillance Towed Array Sensor System (SURTASS)-equipped ship that feeds data into the US Integrated Undersea Surveillance System (IUSS). The Type 927 is assessed to perform a similar function, which includes the detection and tracking of submarines and communicating positional data on contacts of interest to other anti-submarine warfare (ASW)-capable assets.