The Mark 46 torpedo is the backbone of the United States Navy's lightweight anti-submarine warfare torpedo inventory and is the NATO standard. These aerial torpedoes are designed to attack high-performance submarines. In 1989, an improvement program for the Mod 5 to the Mod 5A and Mod 5A(S) increased its shallow-water performance. The Mark 46 was initially developed as Research Torpedo Concept I (RETORC I), one of several weapons recommended for implementation by Project Nobska, a 1956 summer study on submarine warfare.
Design details
=== Variants === Mod 0: One of the original versions of 1960 (production started 1963). Solid propellent piston engine. Gyro/wire guidance with passive/active homing. Mod 1: Based on Mod 0. 1967. Uses liquid Otto fuel piston engine. Laminar search guidance. Phase 1 of 1968 uses stronger hull to resist deeper waters. Phase 2 of 1971 uses a new homing program able to detect submarines near the surface. Mod 2: Based on Mod 1 phase 2. More powerful Mk 103 Mod 1 warhead. Improved computer with snake search pattern capability. Known to have been captured by China in 1978. Mod 4: Version for use as Mark 60 CAPTOR mine payload. Mod 5: 1979 upgrade kit for Mod 2, also known as NEARTIP (near-term improvement program). New passive/active sonar, liquid fuel and two speed engine for low speed search and high speed attack. Mod 5A: Cheaper NEARTIP upgrade kit for Mod 1 and Mod 2 with improved shallow-water performance. 1980s. Mod 5A(S): Variant of 5A that allows use in water as shallow as 40 m. Mod 5A(SW): Latest variant from 1996 Service Life Extension Program. Boasts improved counter-countermeasure performance, enhanced target acquisition, provides a bottom-avoidance preset, and improved maintainability and reliability. Mod 6: Version for Mark 60 CAPTOR, with some NEARTIP components. Mod 7: canceled. Not funded by Congress. For most variants there is also an inert REXTORP (recoverable exercise torpedo) version.
=== Specifications === Mark 46, Mod 5 Primary Function: Air and ship-launched lightweight torpedo Contractor: Alliant Techsystems Power Plant: Two-speed, reciprocating external combustion; Mono-propellant (Otto fuel II) Length: 8 ft 6 in (2.59 m) tube launch configuration (from ship), 14 ft 9 in (4.50 m) with ASROC rocket booster Weight: 508 lb (230 kg) (warshot configuration) Diameter: 12.75 in (324 mm) Range: 12,000 yd (11,000 m) Depth: > 1,200 ft (370 m) Speed: > 40 kn (74 km/h; 46 mph) Guidance System: Homing mode: Active or passive/active acoustic homing Launch/search mode: Snake or circle search Warhead: 96.8 lb (43.9 kg) of PBXN-103 high explosive (bulk charge) Date Deployed: 1967 (Mod 0); 1979 (Mod 5)
== Yu-7 variant == The Chinese Yu-7 torpedo is said to be based on the Mk 46 Mod 2. The Chinese Navy used the Yu-7 ASW torpedo, deployed primarily on ships and ASW helicopters, but it started to be replaced by the Yu-11 in 2012.
Operators
Gallery
== See also == Advanced Light Torpedo Shyena CAPTOR mine (a sea mine which incorporates a Mk 46 torpedo) MU90 Impact torpedo Mark 50 torpedo Mark 54 MAKO Lightweight Torpedo Stingray torpedo
References
== External links == DiGiulian, Tony, Navweaps.com: USA Torpedoes Unofficial U.S. Navy Site: MK-46 Torpedo FAS: MK-46 Torpedo
