Type 53-65K

Type 53 is the common name for a family of 53 cm (21 inch) torpedoes manufactured in Russia, starting with the 53-27 torpedo and continuing to the modern UGST.

With the exception of the UGST which uses Mark 48 style monopropellants, Soviet 53 cm torpedoes generally use electric power (since middle of World War II), or kerosene mixed with various oxidizers for propulsion. Russian torpedoes are often named descriptively for their characteristics – examples include "acoustic homing" or "electric torpedo", all in Russian acronyms.

Model 53-27 with 265 kg of TNT was developed domestically in the so-called Ostekhbureau (), and it has poor 3.7 km range (45 kts). In 1932 USSR bought in Italy several types of torpedoes, and the 21-inch model of Whitehead plant in Fiume (in the Soviet Union it was designated 53F) was considered superior. After adapting several features from the latter in unsuccessful 53-36 the decision was made to copy 53F. Resulting 53-38 (3 speed regimes, range up to 10 km, 300 kg of trotyl in warhead) was later upgraded to 53-38U (400 kg of TNT, roughly the same characteristics) and then redesigned in 53-39 (317 kg, up to 51 kt), considered to be one of the fastest in the world at the time (another were secret Japanese oxygen torpedoes and the Italian Silure Tipo W. 270/533,4 × 7,20 Veloce).

The first Soviet torpedo with homing capability was the SAET-50. The 53-61 was the first Soviet homing torpedo to exceed 40 knots.

The 53-65 torpedo family are Russian made, wake-homing torpedoes designed to destroy surface ships. The 53-65 became operational in 1965, while the 53-65K and 53-65M both became operational in 1969. The 53-65KE is an exported version. China received an unknown number of 53-65KE torpedoes from Russia after purchasing 4 Kilo class submarines in the 1990s.

The Type 53 torpedo is carried by almost all Russian submarines, including the Kilo class and the Akula-class submarine.

The Type 53-65 torpedo is considered especially threatening by the United States Navy because they do not respond to usual torpedo countermeasures. Normal countermeasures are decoys that use noise to divert homing torpedoes, but the Type 53-65 uses sensors that detect the churn made by ships moving, then follows the chopped water in an S-pattern between the wakes until impact from up to 11.8 mi (19.0 km; 10.3 nmi) away. Wake homing torpedoes have caused the U.S. Navy to develop the Surface Ship Torpedo Defense (SSTD) system that employs a maneuvering Countermeasure Anti-Torpedo (CAT) that seeks and intercepts an incoming torpedo.

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