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Mk 46


Mk 46 torpedo

A Mk 46 torpedo being launched from a Mk 32 three round launcher.
Source: US Navy (hotographer's Mate 3rd Class Ramon Preciado) - © public domain

United States
Lightweight torpedo
Entered service
1967 for Mod 0
1979 for Mod 5
1989 for Mod 5A
In service
1960 - 1963
United States - Aerojet-General
1966 - ?
United States - Aerojet-General (Mod 0)
United States - Honeywell (main producer)
Japan - Mitsubishi Heavy Industries
Number produced
Over 26.000 Mk 46 produced, including:
6.608 Mod 1
3.344 Mod 2
4.922 NEARTIP upgrade kits
6.058 Mod 5
NEARTIP (improvement program)



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.


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.


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.


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 platforms

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.


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.


Mk 46 torpedo

A Mk 46 torpedo being launched from a surface vessel.
Source: US Navy (photographer unknown) - © public domain

Variants of the 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.


Facts Mk 46 Mod 0 Mk 46 Mod 1 Mk 46 Mod 5 NEARTIP
United States
Lightweight torpedo
Launch platform
Aircraft, surface ships, ASROC
Target platform
324 mm
2.59 m
259 kg
45 kg Mk 103 Mod 0 warhead with PBX filling
Active/passive acoustic seeker
Homing range
460 m
Wire guidance
Power source
Solid fuel turbine motor
Twin propeller
35 kt
7.5 km
15 to 350 m below sea level


Related articles

Mk 44

The Mk 46 was developed as a successor to the Mk 44 due to the introduction of nuclear powered submarines.

Mark 60 CAPTOR

The Mk 46 Mod 4 and Mod 6 serve as payload for the Mark 60 Encapsulated Torpedo moored naval mine.

Mk 50

The Mk 50 lightweight torpedo was developed as a more capable torpedo for use against advanced Soviet submarines.


The Chinese Yu-7 lightweight torpedo uses an Otto fuel engine reverse engineered using a Mk 46 Mod 2 torpedo.