View source for Mark 46 torpedo

{{Short description|Lightweight antisubmarine torpedo}}
{{For|other weapons designated Mark 46|Mark 46 (disambiguation){{!}}Mark 46}}
{{Use dmy dates|date=June 2017}}
{{Infobox weapon
|name            = Mark 46 torpedo
| image           = File:Mark 46 torpedo launched by DD-980 1996.JPEG
| image_size      = 300
|caption         = A Mk 46 exercise torpedo launched from {{USS|Moosbrugger|DD-980|6}}.
|origin          = United States<!-- Please DON'T add those tiny flags, as they limit horizontal space (Read [WP:Manual of Style/Icons#Avoid flag icons in infoboxes]]). -->
|type            = Lightweight [[Antisubmarine warfare|anti-submarine]] [[torpedo]]<ref name="joliehist">{{cite web | last= Jolie | first = E.W. | title = A Brief History of US Navy Torpedo Development: Torpedo Mk46 | date = 15 September 1978 | url= http://www.maritime.org/doc/jolie/part2.htm | access-date = 24 June 2013}}</ref>
<!-- Type selection -->
|is_ranged       = y
|is_explosive    = y
|is_missile      = y
<!-- Service history -->
|service         = • Mod 0: 1963<ref name="joliehist"/><br>• Mod 5: 1979
|used_by         =[[#Operators|See ''operators'']]
|wars            =
<!-- Production history -->
|designer        = Naval Ordnance Test Station Pasadena<ref name="joliehist"/><br>[[Aerojet]]<ref name="joliehist"/><br>[[Alliant Techsystems]]
|design_date     = 1960<ref name="joliehist"/>
|manufacturer    = [[Aerojet]]<ref name="joliehist"/><br>[[Naval Ordnance Station Forest Park]]<br>[[Honeywell]]<br>[[Raytheon]]<ref name="navy">{{cite web | title = The US Navy Fact File: Mark 46 Torpedo | date = 27 November 2012 | url = http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=900&ct=2 | access-date = August 9, 2018 | archive-date = 20 March 2019 | archive-url = https://web.archive.org/web/20190320025704/https://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=900&ct=2 | url-status = dead }}</ref>
|unit_cost       =
|production_date =
|number          =
|variants        = Mod 0<ref name="joliehist"/><br>Mod 1<br>Mod 2<br>Mod 5<br>Mod 5A<br>Mod 5A(S)<br>Mod 5A(SW)<ref name="navy"/>
<!-- General specifications -->
|weight          = {{convert|508|lb|abbr=on|lk=on}}
|length          = {{convert|8|ft|6|in|abbr=on|lk=on}}
|part_length     =
|width           =
|height          =
|diameter        = {{convert|12.75|in|1|abbr=on|lk=on}}
|crew            =
<!-- Ranged weapon specifications -->
|range           =
|max_range       =
<!-- Explosive specifications -->
|filling         = [[Polymer-bonded explosive|PBXN-103]] high explosive (bulk charge)
|filling_weight  = {{convert|96.8|lb|abbr=on}}
|detonation      =
|yield           =
<!-- Vehicle/missile specifications -->
|engine          = Two-speed, reciprocating external combustion
|engine_power    =
|pw_ratio        =
|transmission    =
|payload_capacity=
|propellant      = [[Otto fuel II]]
|fuel_capacity   =
|vehicle_range   = {{convert|12000|yd|m|abbr=on|lk=on}}
|ceiling         =
|altitude        =
|depth           = >{{convert|1200|ft|m|abbr=on}}
|boost           =
|speed           = >{{convert|40|kn|km/h mph|abbr=on|lk=on}}
|guidance        = Active or passive/active [[acoustic homing]]
|steering        =
|accuracy        =
|launch_platform = [[Mark 32 Surface Vessel Torpedo Tubes]], [[Anti-submarine warfare|ASW]] Aircraft, [[RUM-139 VL-ASROC]]
|transport       =
}}

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 torpedo]]es 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]].<ref>{{cite book | last = Friedman | first = Norman | author-link = Norman Friedman | title = U.S. Submarines Since 1945: An Illustrated Design History | publisher = Naval Institute Press | year = 1994 | location = [[Annapolis, Maryland]] | pages = [https://archive.org/details/ussubmarinessinc1945frie/page/n120 109]-114 | url =https://archive.org/details/ussubmarinessinc1945frie| url-access = limited | isbn = 1-55750-260-9}}</ref>

<gallery widths="200" heights="200">
File:Mark-46-prop.jpg|A Mark 46 Mod 5A torpedo is inspected aboard the guided missile destroyer {{USS|Mustin|DDG-89|6}}.
File:Lynx mk46.jpg|A French [[Lynx (helicopter)|Lynx]] helicopter carrying a Mk 46 torpedo.
File:P-8A Poseidon of VP-16 dropping torpedo in 2013.JPG|A [[P-8A Poseidon]] of VP-16 dropping a Mark 46 torpedo
</gallery>

==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.<ref name="joliehist"/>
* Mod 1: Based on Mod 0. 1967. Uses liquid Otto fuel piston engine. Laminar search guidance.<ref name="joliehist"/> 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.<ref name="ws46"/>
* Mod 2: Based on Mod 1 phase 2. More powerful Mk 103 Mod 1 warhead. Improved computer with snake search pattern capability.<ref name="ws46"/> Known to have been captured by China in 1978.<ref name="janes_dragon" />
* Mod 4: Version for use as [[Mark 60 CAPTOR]] mine payload.<ref name="ws60">{{cite web |title=Mark 60 CAPTOR |url=https://weaponsystems.net/system/449-Mark%2060%20CAPTOR |website=Weaponsystems.net |language=en}}</ref><ref>{{cite web |last1=Simeral |first1=R. T. |title=Torpedo MK 46 Physical Characteristics. |url=https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/ADA081111.xhtml |publisher=Naval Ocean Systems Center, San Diego, CA.; Government-Industry Data Exchange Program |date=1978}} [https://apps.dtic.mil/sti/tr/pdf/ADA081111.pdf ADA081111.pdf]</ref>
* 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.<ref name="ws46">{{cite web |title=Mk 46 |url=https://weaponsystems.net/system/450-Mk%2046 |website=Weaponsystems.net |language=en}}</ref>
** Mod 5A: Cheaper NEARTIP upgrade kit for Mod 1 and Mod 2 with improved shallow-water performance. 1980s.<ref name="ws46" />
** Mod 5A(S): Variant of 5A that allows use in water as shallow as 40 m.<ref name="ws46" />
** Mod 5A(SW): Latest variant from 1996 Service Life Extension Program.<ref name="ws46" /> Boasts improved counter-countermeasure performance, enhanced target acquisition, provides a bottom-avoidance preset, and improved maintainability and reliability.<ref name="navy" />
* Mod 6: Version for Mark 60 CAPTOR, with some NEARTIP components.<ref name="ws60" />
* Mod 7: Cancelled. Not funded by Congress.<ref name="unoff">{{cite web |title=MK-46 Torpedo |url=https://www.navysite.de/weapons/mk-46.htm |website=www.navysite.de}}</ref>

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<ref name="1987 almanac">Thomas, Vincent C. ''The Almanac of Seapower 1987'' Navy League of the United States (1987) {{ISBN|0-9610724-8-2}} pp.190-191</ref>
* Contractor: [[Alliant Techsystems]]
* Power Plant: Two-speed, reciprocating external combustion; Mono-propellant ([[Otto fuel II]])
* Length: {{convert|8|ft|6|in|m|2|abbr=on}} tube launch configuration (from ship),<ref name="proceedings">Polmar, Norman "The Ships and Aircraft of the U.S. Fleet: Torpedoes" ''United States Naval Institute Proceedings'' November 1978 p.160</ref> {{convert|14|ft|9|in|m|2|abbr=on}} with [[ASROC]] rocket booster<ref name="1987 almanac"/>
* Weight: {{convert|508|lb|kg|0|abbr=on}}<ref name="1987 almanac"/> (warshot configuration)
* Diameter: {{convert|12.75|in|mm|abbr=on}}<ref name="proceedings"/>
* Range: {{convert|12,000|yd|m|abbr=on}}<ref name="1987 almanac"/>
* Depth: > {{convert|1200|ft|m|abbr=on}}
* Speed: > {{convert|40|knots|kph mph|abbr=on}}<ref name="1987 almanac"/>
* Guidance System: Homing mode: Active or <nowiki>passive/active</nowiki> [[acoustic homing]]<ref name="proceedings"/>
* Launch/search mode: Snake or circle search
* Warhead: {{convert|96.8|lb|kg|1|abbr=on}}<ref name="1987 almanac"/> of [[Polymer-bonded explosive|PBXN-103]] high explosive (bulk charge)
* Date Deployed: 1967 (Mod 0);<ref name="1987 almanac"/> 1979 (Mod 5)

==Yu-7 variant==
The Chinese [[Yu-7 torpedo]] is said to be based on the Mk 46 Mod 2. The [[People's Liberation Army Navy|Chinese Navy]] used the Yu-7 ASW torpedo, deployed primarily on ships and ASW helicopters,<ref name="chinese">[http://mil.jschina.com.cn/huitong/missile1.htm (Chinese language)] {{webarchive|url=https://web.archive.org/web/20061102073156/http://mil.jschina.com.cn/huitong/missile1.htm |date=2006-11-02 }}</ref> but it started to be replaced by the Yu-11 in 2012.<ref name="janes_dragon">{{cite web |url= https://www.janes.com/images/assets/911/72911/Undersea_dragon_Chinese_ASW_capabilities_advance.pdf |title=Undersea dragon: Chinese ASW capabilities advance |publisher=Jane's |date=2017 |access-date=23 July 2019}}</ref>

==Operators==
{{More citations needed section|date=October 2023}}
{{div col|colwidth=12em}}
*{{flag|Australia}}
*{{flag|Bahrain}}
*{{flag|Belgium}}
*{{flag|Brazil}}
*{{flag|Canada}}
*{{flag|Chile}}
*{{flag|Colombia}}
*{{flag|Croatia}}
*{{flag|Ecuador}}
*{{flag|Egypt}}
*{{flag|France}}
*{{flag|Germany}}
*{{flag|Greece}}
*{{flag|Indonesia}}
*{{flag|Iran}}
*{{flag|Israel}}
*{{flag|Italy}}
*{{flag|Japan}}
*{{flag|Kuwait}}
*{{flag|Mexico}}
*{{flag|Morocco}}
*{{flag|Netherlands}}
*{{flag|New Zealand}}
*{{flag|Norway}}
*{{flag|Pakistan}}
*{{flag|Peru}}
*{{flag|Philippines}}<ref>{{Cite web |title=Frigate Lot 3A - Torpedoes Acquisition Project of the Philippine Navy |url=https://www.phdefenseresource.com/2021/04/frigate-lot-3a-torpedoes-acquisition.html?m=1 |website=www.phdefenseresource.com |date=3 April 2021}}</ref>
*{{flag|Portugal}}
*{{flag|Saudi Arabia}}
*{{flag|South Korea}}
*{{flag|Spain}}
*{{flag|Taiwan}}
*{{flag|Thailand}}
*{{flag|Turkey}}
*{{flag|United Arab Emirates}}
*{{flag|United Kingdom}}
*{{flag|United States}}<ref name="weaponsystems">{{cite web|url=http://www.weaponsystems.net/weapon.php?weapon=HH14+-+Mk+46|title=Mk 46 torpedo - Weaponsystems.net|website=www.weaponsystems.net}}</ref>
{{div col end}}

==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 LHT|Mark 54]] MAKO Lightweight Torpedo
* [[Sting Ray (torpedo)|Stingray]] torpedo

==References==
{{Reflist}}

==External links==
* [http://www.navweaps.com/Weapons/WTUS_PostWWII.htm DiGiulian, Tony, Navweaps.com: USA Torpedoes]
* [http://www.navysite.de/weapons/mk-46.htm Unofficial U.S. Navy Site: MK-46 Torpedo]
* [http://www.fas.org/man/dod-101/sys/ship/weaps/mk-46.htm FAS: MK-46 Torpedo]

{{Mark-series torpedoes}}

{{DEFAULTSORT:Mark 46 Torpedo}}
[[Category:Aerial torpedoes]]
[[Category:Cold War anti-submarine weapons of the United States]]
[[Category:Military equipment introduced in the 1960s]]
[[Category:Torpedoes of the United Kingdom]]
[[Category:Torpedoes of the United States]]