Munitions / Torpedoes / Mk 46 torpedo

Mk 46 torpedo

General Facts

  • TYPE
    Torpedo

  • ORIGIN
    United States

  • NICKNAMES
    NEARTIP (improvement program)

  • DESIGNED
    1960 - 1963

  • DESIGNER
    Aerojet-General

  • PRODUCTION
    1966 - 1987

  • PRODUCERS
    Japan - Mitsubishi (Mod 5)
    United States - Aerojet-General (Mod 0)
    United States - Alliant Techsystems (CAPTOR mine)
    United States - Honeywell (main producer)

  • QUANTITY
    Over 26.000 Mk 46 produced, including:
    6.608 Mod 1
    3.344 Mod 2
    4.922 NEARTIP upgrade kits
    6.058 Mod 5

  • UNIT COST
    Unknown

  • CHARACTERISTICS
    Good speed and range
    Powerful warhead for lightweight torpedo
    Dedicated shallow water upgrades
    Can be launched from many platforms
    Complex design and expensive

Introduction

The Mk 46 is a lightweight torpedo of US origin. It was developed in the early 1960's to replace the successful Mk 44 torpedo. It was the first high performance thermal powered torpedo in US service. The complex but powerful propulsion system was chosen to keep up with Soviet submarine developments. The Mk 46 is the most common lightweight torpedo in the world and remains in widespread use.

Layout

The Mk 46 has a conventional layout with the homing section and warhead in the nose, the fuel in the middle and the engine and control fins at the rear. Apart from the original production version all Mk 46 use an Otto fuel engine. Over time the design was improved with improved guidance, stronger body, new fuel and two speed engine.

Guidance

The Mk 46 uses a passive and active sonar guidance system. Over time the quality of the seeker has been improved. The seeker on the Mk 46 Mod 2 reportedly has a detection range of 460 meters. The latest models received various upgrades to improve performance in shallow water.

Firepower

The Mk 46 has a range of 8 km and a speed of 40 to 45 kt. The NEARTIP improvement includes a two speed motor which extends the range up to 11 km. The Mk 46 can engage targets ranging from 15 to over 400 meters below sea level. The 45 kg warhead is more powerful than those used on many other lightweight torpedoes.

Launch platform

The Mk 46 is found on many surface vessels ranging from frigates to cruisers. The Mk 46 can also be air launched and is used on various helicopters such as the SH-60 Seahawk, the Sea King and the Lynx. The Mk 46 is also deployed by more unconventional means such as the Mk 60 CAPTOR mine and ASROC anti-submarine rocket.

Users

The main user of the Mk 46 is the US navy. Subsequent upgrades ensure that the Mk 46 remains a capable weapon, although the very latest lightweight torpedo designs feature both better guidance and propulsion. The Mk 46 is in use with many NATO partners and various other US allies, making it the most numerous lightweight torpedo in the world.

Variants

Mk 46 torpedo

Mk 46 torpedo

Mk 46 Mod 0: Original production version with unreliable solid fuel turbine motor introduced in 1963.
Mk 46 Mod 1: Extensively upgraded Mod 0 with original engine replaced by Otto fuel engine. The 1968 phase 1 upgrade included a stronger hull that increased maximum operating depth from 350 to over 400 meters. The 1971 phase 2 upgrade allowed the homing system to detect submarines near the surface.
Mk 46 Mod 2: Mod 1 phase 2 with more powerful Mk 103 Mod 1 warhead and improved computer with snake search pattern capability. Introduced in 1972.
Mk 46 Mod 5 NEARTIP: Upgrade kit for the Mod 2 with new passive/active sonar, liquid fuel and two speed engine for low speed search and high speed attack. Introduced in 1979. NEARTIP stands for Near Term Improvement Program.
Mk 46 Mod 5A: Cheaper NEARTIP upgrade kit for Mod 1 or Mod 2. Developed in the mid-1980's specifically for use in shallow water. The Mod 5 A(S) can be used in water as shallow as 40 meters and the Mod 5A(SW) is the latest version introduced in 1996.

Statistics

Name: Mk 46 Mod 0Mk 46 Mod 1Mk 46 Mod 5
Type Anti-submarine torpedoAnti-submarine torpedoAnti-submarine torpedo
Platform Aircraft, surface ships, ASROCAircraft, surface ships, ASROCAircraft, surface ships, ASROC
Diameter 324 mm324 mm324 mm
Length 2.59 m2.59 m2.59 m
Weight 259 kg232 kg234.8 kg
Warhead 45 kg Mk 103 Mod 0 warhead with PBX filling45 kg Mk 103 Mod 0 warhead with PBX filling45 kg Mk 103 Mod 1 warhead with PBXN filling
Guidance Active/passive acoustic seeker, 460 m homing rangeActive/passive acoustic seeker, 460 m homing rangeActive/passive acoustic seeker
Propulsion Twin propellerTwin propellerTwin propeller
Power supply Solid fuel turbine motorMonopropellant Otto fuel engineLiquid propellant Otto fuel engine
Speed 35 kt40 kt40 kt
Range 7.5 km8.3 km11 km
Depth 15 to 350 m below sea level15 to 450 m below sea level15 to 450 m below sea level
Mk 60 CAPTOR mine

Mark 60 CAPTOR mine

The CAPTOR mine is an anti-submarine mine that is laid by aircraft, surface vessels or submarines. The name CAPTOR stands for Encapsulated Torpedo. The mine is moored to the sea floor and detects nearby vessels using passive sonar. It is designed to only engage submarines. The submarine launched version of the CAPTOR differs from the air and surface vessel launched version as it is made to fit into a 533mm torpedo tube.

Mk 46 Mod 4: Mk 46 that serves as payload for the CAPTOR anti-submarine mine, introduced in 1973
Mk 46 Mod 6: The Mod 6 is a CAPTOR version of the Mk 46 that uses some NEARTIP components.

Statistics

Name: Mk 60 CAPTORMk 60 CAPTOR (submarine)
Type Anti-submarine mineAnti-submarine mine
Platform Aircraft, surface ships, submarinesAircraft, surface ships, submarines
Diameter 530 mm530 mm
Length 3.68 m3.35 m
Weight 1.077 kg935 kg
Warhead Mk 46 Mod 4 or Mod 6 torpedoMk 46 Mod 4 or Mod 6 torpedo
Guidance Reliable acoustic path sound propagationReliable acoustic path sound propagation
Propulsion --
Power supply --
Speed --
Range --
Depth Over 370 mOver 370 m

Media

Use

 
Australia
Bahrain
Belgium
Brazil
Canada
Chile
China

Egypt
France
Germany
Greece
Indonesia
Iran
Israel

Italy
Japan
Kuwait
Mexico
Morocco
Netherlands
New Zealand

Norway
Pakistan
Peru
Portugal
Saudi Arabia
South Korea
Spain

Taiwan
Thailand
Turkey
United Arab Emirates
United Kingdom
United States
Venezuela

Mk 50 torpedo

The design of the Mk 50 is based on the older Mk 46, but differs in nearly every area.

Yu-7 torpedo

The Chinese Yu-7 torpedo is derived from the Mk 46 and borrows some components from the Italian A.224S.