Romeo Class Submarine - Chinese Romeo Class Submarines and Their Derivatives

Chinese Romeo Class Submarines and Their Derivatives

Under the 1950 Sino-Soviet Friendship and Mutual Assistance Treaty, the Soviets passed to China (and later to North Korea) the documentation necessary to produce Romeo submarines in 1963. The Chinese variant is known as the Type 033 Romeo. A total of 84 Type 033 submarines were built in China from 1962 to 1984, plus several exported to other countries. The Chinese Type 033 incorporated some improvements over the original Romeo, including noise reduction of at least 20 dB. Sonar on board was also continuously upgraded: the original Soviet sonar was first replaced by domestic Chinese Type 105 sonar, which consequently was replaced by H/SQ2-262A sonar built by No. 613 Factory. A single Type 033 was modified to carry 6 YJ-1 (CSS-N-4) SSM, this variant is called Type 033G Wuhan. Today most of the Type 033 subs have been retired or preserved, with few remaining for training purposes.

In the 1970s, China's Wuhan Ship Development and Design Institute (701 Institute) built an improved submarine based on the Type 033 hull, named Type 035 Ming. The 035 Ming had an improved diesel-electric engine, improved hull design with less hydrodynamic resistance, better underwater speed, and a more capable sonar, the H/SQZ-262 built by No. 613 Factory replacing the Type 105 sonar used on Type 033 submarines. A total of 21 Type 035 Ming sub were built between 1971 and 2000. There are at least 4 known variants of the Type 035 Ming, ES5C, ES5D, ES5E, and ES5F. The last variant, ES5F, is sometimes referred to as the Type 035G, and upgrades included H/SQZ-262C sonar built by No. 613 Factory replacing the original H/SQZ-262 used on the original Type 035 submarines. Today, 17 Type 035 Ming subs remain in service with the People's Liberation Army Navy (PLAN). One Type 035 Ming is said to have been modified as a test-bed for new Air Independent Propulsion (AIP) system.