The Project 633 class (known in the West by its NATO reporting name as the Romeo class) is a class of Soviet diesel-electric submarine, built between 1957 and 1961. A Chinese variant, Type 033, was built in China from 1962 to 1984.

Project 633

Project 633 was a further development of the Soviet navy's post-war 611 (Zulu-) and 613 (Whiskey-class) designs, which themselves were derivatives of the German Kriegsmarine Type XXI submarine. The project was undertaken by Lazurit Central Design Bureau of Gorky. Only 20 of the Soviet Union's originally intended 56 were completed between October 1957 and the end of December 1961 because of the introduction of the nuclear submarine into the Soviet Navy. By today's standards Romeo class submarines are considered obsolete, but they still have some value as training and surveillance vessels.

Chinese Type 033 Romeo class and its variants

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, 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. Today most of the Type 033 subs have been retired or preserved, with a few remaining in service for training purposes. A total of six Chinese Romeo-class submarine variants were developed:

Operators

Current

Currently four countries are using Romeo class submarines in an operational capacity: Currently using Romeo class submarines in non-operational capacities (i.e. training):

Former

No longer using Romeo class submarines in any reported capacity:

Surviving boats

Citations