View source for Mark 54 lightweight torpedo

{{short description|American torpedo}}
{{use American English|date=October 2020}}
{{Infobox weapon
|name=Mark 54 lightweight torpedo
|image=File:WTUS PostWWII mk54 pic.jpg
|caption=Mark 54 torpedo aboard {{USS|Ross|DDG-71|6}} in March 2008.
|origin= United States
|type=Lightweight [[anti-submarine warfare|ASW]] [[torpedo]]
<!-- Type selection -->
|is_ranged=y
|is_explosive=y
|is_missile=y
<!-- Service history -->
|service=2004–present
|used_by= [[United States Navy]]<br />[[Royal Australian Navy]]<br />[[Royal Canadian Navy]]<br />[[Royal Air Force]]<br />[[Royal Thai Navy]]<br />[[Royal Netherlands Navy]]<br />[[Republic of China Navy]]
|wars=
<!-- Production history -->
|designer=[[Raytheon|Raytheon Systems]]
|design_date=1999
|manufacturer=
|unit_cost=US$839,320 <small>(FY2014)</small><ref>{{cite web | url=http://thomas.loc.gov/cgi-bin/cpquery/?&sid=cp113DzuqB&r_n=sr044.113&dbname=cp113&&sel=TOC_830520& | title=Senate Report 113-044 - NATIONAL DEFENSE AUTHORIZATION ACT FOR FISCAL YEAR 2014 | publisher=Library of Congress | date=20 June 2013 | access-date=2013-11-07 }}{{Dead link|date=August 2021 |bot=InternetArchiveBot |fix-attempted=yes }} 150 Mk 54 cost $125.898m in financial year 2014</ref>
|production_date=2003
|number=
|variants=
<!-- General specifications -->
|spec_label=
|weight= {{convert|608|lb|kg|abbr=on}}<ref name=USNFF>{{cite web | url=http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=1100&ct=2 | title=Fact File: Mk54 Torpedo | publisher=US Navy | date=27 November 2012 | access-date=2013-11-07 | archive-url=https://web.archive.org/web/20130513045055/http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=1100&ct=2 | archive-date=13 May 2013 | url-status=dead }}</ref>
|length= {{convert|106.9|in|m|abbr=on}}<ref name=USNFF />
|part_length=
|width=
|height=
|diameter={{convert|12.75|in|mm|abbr=on}}<ref name=USNFF />
|crew=
<!-- Ranged weapon specifications -->
|cartridge=
|caliber=
|barrels=
|action=
|rate=
|velocity=
|range= 
|max_range=
|feed=
|sights=
<!-- Explosive specifications -->
|filling=[[Polymer-bonded explosive|PBX]]N-103
|filling_weight={{convert|96.8|lb|kg|abbr=on}}<ref name=USNFF />
|detonation=
|yield= {{convert|238|lb|kg|abbr=on}} TNT
<!-- Vehicle/missile specifications -->
|armour=
|primary_armament=
|secondary_armament=
|engine=Reciprocating external combustion
|engine_power=
|pw_ratio=
|transmission=
|payload_capacity=
|suspension=
|clearance=
|wingspan=
|propellant=[[Otto fuel II|Otto II]] (liquid)
|fuel_capacity=
|vehicle_range= {{convert|10000|yd|km|abbr=on|sigfig=2}}
|ceiling=
|altitude=
|depth= >{{convert|450|m|ft}} (estimate)<ref>{{cite web |title=Mk 54 |url=https://weaponsystems.net/system/1606-Mk%2054 |website=Weaponsystems.net |language=en}}</ref>
|boost=
|speed= >{{convert|40|kn|abbr=on|lk=on|1}}
|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 54 lightweight torpedo''' (formerly known as '''lightweight hybrid torpedo''', or '''LHT''') is a standard {{convert|12.75|in|mm|adj=on}} [[anti-submarine warfare]] (ASW) [[torpedo]] used by the [[United States Navy]] and several other nations armed forces.

== Development ==
The Mark 54 was co-developed by [[Raytheon]] Integrated Defense Systems and the [[United States Navy]] (USN) under the USN's Lightweight Hybrid Torpedo program in response to perceived problems with the extant [[Mark 50 torpedo|Mark 50]] and [[Mark 46 torpedo|Mark 46]] torpedoes. The Mk 50, having been developed to counter very high performance [[nuclear submarine]]s such as the [[Soviet Union|Soviet]] {{sclass|Alfa|submarine|4}}, was seen as too expensive to use against relatively slow conventional submarines. The older Mk 46, designed for open-ocean use, performed poorly in the [[littoral]] areas, where the USN envisioned itself likely to operate in the future.

[[File:USS Roosevelt (DDG-80) launches Mk 54 torpedo in April 2014.JPG|thumb|left|{{USS|Roosevelt|DDG-80|6}} launches a Mk 54 torpedo.]]

The Mk 54 was created by combining the homing portion of the Mk 50 and the warhead and propulsion sections of the Mk 46, improved for better performance in shallow water, and with the addition of commercial off-the-shelf (COTS) technology to further reduce costs. It shares much of the software and computer hardware of the [[Mark 48 torpedo|Mk 48 ADCAP heavy torpedo]], based on a custom [[PowerPC 603e]] microprocessor. Developmental testing began in July 1999, and a successful critical design review was completed in November 1999.

In April 2003, Raytheon was awarded a sole source contract for the production of the Mk 54. Full rate production began in October 2004. In March 2010 the [[United States Fifth Fleet]] requested improvements in the Mk 54's performance against [[diesel-electric submarine]]s via an Urgent Operational Need Statement (UONS). This led to a software Block Upgrade (BUG) program which began testing in August 2011 and which continues, having been criticized by the [[Director, Operational Test and Evaluation]] (DOT&E) for using unrealistic proxies for threat submarines.<ref>{{cite web |url= http://www.dote.osd.mil/pub/reports/fy2012/pdf/navy/2012mk54.pdf |title= Mk 54 Lightweight Torpedo |website= Director, Operational Test & Evaluation (DOT&E) |date= 2012 |access-date= 7 November 2013 |archive-url= https://web.archive.org/web/20140826115957/http://www.dote.osd.mil/pub/reports/fy2012/pdf/navy/2012mk54.pdf |archive-date= 26 August 2014 |url-status= dead }}</ref>

The Mk 54 can be fired from surface ships via the [[Mark 32 surface vessel torpedo tubes]] or the [[RUM-139 VL-ASROC|vertical launch anti-submarine rocket]] (VL-ASROC) systems, and also from most ASW aircraft, although they are slightly different lengths and weights. The [[Boeing P-8 Poseidon|P-8 Poseidon]] uses the High-Altitude Anti-Submarine Warfare Weapons Capability (HAAWC) GPS-guided glide kit to drop torpedoes from high altitude.<ref>{{cite web |url=https://www.militaryaerospace.com/computers/article/16715935/boeing-to-make-flying-torpedoes-able-to-attack-enemy-submarines-from-30000-feet |title=Boeing to make flying torpedoes able to attack enemy submarines from 30,000 feet |work=Military + Aerospace Electronics |date=4 April 2013 |access-date=30 June 2025}}</ref>

The FY14 DOT&E report assessed the Mk 54 (BUG) torpedo as not operationally effective in its intended role: "During operationally challenging and realistic scenarios, the Mk 54 (BUG) demonstrated below threshold performance and exhibited many of the same failure mechanisms observed during the FY 2004 initial operational testing".  Shortfalls were also identified with the employing platforms’ tactics and tactical documentation, and interoperability problems with some platform fire control systems.<ref name=FY14>{{cite web |url= http://www.dote.osd.mil/pub/reports/FY2014/pdf/navy/2014mk54.pdf |title= Mk 54 Lightweight Torpedo FY14 |publisher= Director, Operational Test & Evaluation (DOT&E) |date= 2015 |access-date= 25 January 2015 |archive-url= https://web.archive.org/web/20150531185258/http://www.dote.osd.mil/pub/reports/FY2014/pdf/navy/2014mk54.pdf |archive-date= 31 May 2015 |url-status= dead }}</ref>

As of 2015, a new version to be designated Mk 54 Mod 1 is in development. It is intended to enter operational testing and evaluation in 2017.<ref name=FY14/>

==Operators==

===Current operators===
;{{AUS}}
* [[Royal Australian Navy]] - In October 2010, Australia ordered 200 more torpedoes.<ref>{{cite web |url= http://www.defenseindustrydaily.com/team-torpedo-raytheon-partners-to-support-mk48-and-mk54-requirements-02533/ |website= Defense Industry Daily |date= 2014-08-21 |access-date= 2010-10-12 |title= Team Torpedo: US Firms Sell & Support MK48s and MK54s |archive-url= https://web.archive.org/web/20120916104649/http://www.defenseindustrydaily.com/team-torpedo-raytheon-partners-to-support-mk48-and-mk54-requirements-02533/ |archive-date= 16 September 2012 |url-status= live }}</ref>
* [[Royal Australian Air Force]] - The Mk54 Mod 0 is employed on the [[Boeing P-8 Poseidon|P-8A Poseidon]] by [[No. 11 Squadron RAAF]].<ref>{{cite news |url=https://www.defence.gov.au/news-events/news/2024-07-18/poseidon-hunts-submarines-pacific |title=Poseidon hunts submarines in the Pacific |publisher=Australian Government |date=18 July 2024 |first=Carolyn |last=Martin |access-date=30 June 2025}}</ref>
;{{BRA}} 
* [[Brazilian Navy]] - In December 2020, the US Department of State approved for $70 million, the sale for Brazil of 22 Mk 54 lightweight torpedo conversion kits for the Mk 46 Mod 5A torpedoes already in operation in the [[S-70B Seahawk|S-70B]] helicopters of the [[Brazilian Navy]], plus ancillary training, exercise and maintenance spare parts.<ref>{{cite news |title=Proposed Purchase of MK 54 Torpedoes by Brazil Approved|url=https://br.usembassy.gov/proposed-purchase-of-mk-54-torpedoes-by-brazil-approved|website=U.S. Embassy and Consulates in Brazil|date=2 December 2019}}</ref><ref>{{cite news |title=Brazil - Mk 54 Lightweight Torpedoes|url=https://www.dsca.mil/press-media/major-arms-sales/brazil-mk-54-lightweight-torpedoes|website=DSCA|date=2 December 2019}}</ref>
;{{CAN}}
* [[Royal Canadian Air Force]] 
* [[Royal Canadian Navy]]
In May 2019 Canada requested 425 Mk 54 lightweight torpedo conversion kits, plus ancillary training, exercise and maintenance spare parts. This procurement will allow Canada to upgrade its current inventory of [[Mk 46 Torpedo|Mk 46 torpedoes]]. The Mk 54 lightweight torpedoes are expected to be used on the [[Royal Canadian Navy]]'s {{sclass|Halifax|frigate|1}}s, and the [[Royal Canadian Air Force]]'s [[CP-140 Aurora]] aircraft. The torpedoes are also planned to be deployed from the [[Sikorsky CH-148 Cyclone|CH-148 maritime helicopters]].<ref>{{cite web |url=https://www.naval-technology.com/news/canada-requests-387m-sale-of-mk-54-torpedoes-from-us/ |title=Canada requests $387m sale of MK 54 torpedoes from US |work=Naval Technology |date=22 May 2019 |archive-url=https://web.archive.org/web/20190523201614/https://www.naval-technology.com/news/canada-requests-387m-sale-of-mk-54-torpedoes-from-us/ |archive-date=23 May 2019 |access-date=30 June 2025}}</ref> On 17 May 2019, the [[U.S. State Department]] approved the sale worth US$387 million (C$514 million in 2019.) Under Canada's Industrial and Technological Benefits Policy, Canada negotiated an [[Offset agreement]] with Raytheon before signing the final deal in order to leverage jobs and economic benefits in Canada.<ref>{{cite news |last=Coyne |first=Todd |url=https://ctvnews.ca/local/vancouver-island/2019/6/13/1_4465228.html |title=Canada to spend $500M on U.S. anti-submarine torpedo |work=CTV News Vancouver |date=2019-06-13 |access-date=2022-02-10 }}{{dead link|date=June 2025}}</ref>
;{{IND}}
* [[Indian Navy]] - In June 2011, it was reported that India will get 32 Mk 54 All-Up-Round Lightweight Torpedoes and associated equipment, parts, training and logistical support for an estimated cost of $86 million through U.S. government's Foreign Military Sales program for [[Boeing P-8 Poseidon|P-8I]] LRMP.<ref>{{cite web |url= http://www.indianexpress.com/news/us-clears-sale-of-antisubmarine-torpedoes-to-indian-navy/809957/ |title= US clears sale of anti-submarine torpedoes to Indian Navy |website= The Indian Express |date= 2011-06-28 |access-date= 29 June 2011 |archive-url= https://archive.today/20130126151516/http://www.indianexpress.com/news/us-clears-sale-of-antisubmarine-torpedoes-to-indian-navy/809957/ |archive-date= 26 January 2013 |url-status= live }}</ref> In April 2020, [[Defense Security Cooperation Agency]] cleared the possible sale of 16 aircraft-launched Mk 54 Lightweight Torpedo all up rounds and 3 Mk 54 Exercise Torpedoes for its additional [[P-8I]] fleet at a cost of $63 million.<ref name="BBC Ukr Harpoon">{{cite news |last=Beale |first=Jonathan |date=15 June 2022 |title=British rocket launchers to be sent to Ukraine imminently, minister says |url=https://www.bbc.com/news/live/world-europe-61792068?ns_linkname=62a9c40da48d0547a34c0449%26British%20rocket%20launchers%20to%20be%20sent%20to%20Ukraine%20imminently%2C%20minister%20says%262022-06-15T14%3A33%3A42%2B00%3A00&ns_fee=0&pinned_post_locator=urn:asset:9023d6e2-931d-4895-b201-c6f60d721124 |url-status=live |archive-url=https://web.archive.org/web/20240105234347/https://www.bbc.com/news/live/world-europe-61792068?ns_linkname=62a9c40da48d0547a34c0449%26British%20rocket%20launchers%20to%20be%20sent%20to%20Ukraine%20imminently%2C%20minister%20says%262022-06-15T14%3A33%3A42%2B00%3A00&ns_fee=0&pinned_post_locator=urn:asset:9023d6e2-931d-4895-b201-c6f60d721124 |archive-date=5 January 2024 |access-date=1 July 2022 |work=BBC News}}</ref><ref>{{Cite web |last=Vavasseur |first=Xavier |date=2020-04-14 |title=United States Approves Possible FMS of Harpoon & Torpedoes for India's P-8I MPA |url=https://www.navalnews.com/naval-news/2020/04/united-states-approves-possible-fms-of-harpoon-torpedoes-for-indias-p-8i-mpa/ |access-date=2024-10-15 |website=Naval News |language=en-US}}</ref> In October 2024, the United States' [[Defense Security Cooperation Agency]] cleared the possible sale of 53 aircraft-launched Mk 54 Mod 0 lightweight torpedo all up rounds for its [[MH-60R|MH-60R "Romeo"]] fleet and associated equipment and support, including "in-country torpedo training."<ref>{{Cite web |last=Ferran |first=Lee |date=2024-10-07 |title=US greenlights 'electronic attack' system for Italy, torpedoes for India and radars for Romania |url=https://breakingdefense.com/2024/10/us-greenlights-electronic-attack-system-for-italy-torpedoes-for-india-and-radars-for-romania/ |access-date=2024-10-08 |website=Breaking Defense |language=en-US}}</ref>
;{{MEX}}
* [[Mexican Navy]] - In early 2018 the U.S. State Department approved the sale of Mark 54 torpedoes to the [[Mexican Navy]], who will deploy them from their new [[Sigma-class design]] frigates, the first of which is being jointly built with Dutch shipbuilding company [[Damen Schelde Naval Shipbuilding]].<ref>{{cite web |url=http://www.dsca.mil/major-arms-sales/mexico-harpoon-block-ii-missiles-ram-missiles-and-mk-54-torpedoes/ |title= Mexico –Harpoon Block II Missiles, RAM Missiles and MK 54 Torpedoes |url-status=dead |archive-url=https://web.archive.org/web/20180504011354/http://www.dsca.mil/major-arms-sales/mexico-harpoon-block-ii-missiles-ram-missiles-and-mk-54-torpedoes/ |archive-date=4 May 2018 |date=January 2018 |publisher=United States Defense Security Cooperation Agency}}</ref> In April 2018, the U. S. State Department cleared the sale of an additional 30 Mark 54 torpedoes to the Mexican Navy, which may be carried on [[MH-60R]] helicopters, which the Mexican Navy plans to order in the near future.<ref>{{cite web |url=https://thedefensepost.com/2018/04/20/us-approves-sale-mexico-mh-60r-seahawk-helicopters/ |title=US approves $1.2 billion sale to Mexico of 8 MH-60R Seahawk helicopters |archive-url=https://web.archive.org/web/20180504010459/https://thedefensepost.com/2018/04/20/us-approves-sale-mexico-mh-60r-seahawk-helicopters/ |archive-date=4 May 2018 |date=20 April 2018 |work=The Defense Post |last=Kelly |first=Fergus}}</ref>
;{{NZ}}
* [[Royal New Zealand Air Force]] - Have an undisclosed number with the purchase of the P-8A. It was known that the upgrade from the Mk 46 was going to happen via the "Defence Capability Plan 2019" and was stated in the RNZAF News<ref>{{cite web |url=https://issuu.com/nzdefenceforce/docs/royal_new_zealand_air_force_air_for_d7b79f6bbd7be3?fr=sNzU2MDM5NjExMzQ |title= P-8A Poseidon Ordnance | work= Air Force News |date=23 February 2023 |issue=254 |p=25 |url-access=limited}}</ref> that weapon was the Mark 54 torpedo. It is unknown whether the [[Royal New Zealand Navy]] have replaced their Mk46.
;{{NLD}}
* [[Royal Netherlands Navy]] - In 2018 the [[Royal Netherlands Navy]] acquired Mk 54 torpedoes via the Foreign Military Sales process.
;{{UK}}
* [[Royal Air Force]] - In January 2018 it was announced that the P-8 Poseidon aircraft to be operated by the Royal Air Force will carry the Mk 54.<ref>{{cite web |url= https://ukdefencejournal.org.uk/britain-purchase-mk54-lightweight-torpedo-array-kits-destined-p-8-poseidon/ |title= Britain to Purchase Mk 54 Lightweight Torpedo array kits destined for P-8 Poseidon |website= UK Defence Journal |date= 2018-01-04 |access-date= 4 January 2018 |archive-url= https://web.archive.org/web/20180105011802/https://ukdefencejournal.org.uk/britain-purchase-mk54-lightweight-torpedo-array-kits-destined-p-8-poseidon/ |archive-date= 5 January 2018 |url-status= live }}</ref>
;{{US}}
* [[United States Navy]]
;{{GER}}
* [[German Navy]] - In 2020 it was announced that the German Navy ordered 64 weapons for use with its [[Lockheed P-3 Orion|P-3 Orion]] aircraft.<ref>{{Cite web |last=Felstead |first=Peter |date=2023-12-11 |title=MK 54 lightweight torpedoes approved for German Navy P-8As - European Security & Defence |url=https://euro-sd.com/2023/12/major-news/35562/mk-54s-approved-for-germany/ |access-date=2024-04-26 |website=euro-sd.com |language=en-US}}</ref>
;{{ROC}}
* [[Republic of China Navy]] - In 2017 168 Mk 54 torpedo upgrade kits were obtained along with supporting technical support.<ref>{{Cite web |url=https://www.dsca.mil/major-arms-sales/taipei-economic-and-cultural-representative-office-tecro-united-states-mk-54 |title=Taipei Economic and Cultural Representative Office (TECRO) in the United States - Mk 54 Lightweight Torpedo (LWT) Conversion Kits |publisher=United States Defense Security and Cooperation Agency |accessdate=2020-07-25 |archive-date=2020-10-01 |archive-url=https://web.archive.org/web/20201001225019/https://www.dsca.mil/major-arms-sales/taipei-economic-and-cultural-representative-office-tecro-united-states-mk-54 |url-status=dead}}</ref>

==See also==
* [[APR-3E torpedo]] - Russian equivalent
* [[A244-S]] - Italian equivalent (especially the Mk3 variant with a MU90 seeker)
* [[MU90 Impact]] - French/Italian equivalent
* [[Sting Ray (torpedo)]] - British equivalent
* [[Advanced Light Torpedo Shyena|TAL Shyena]] - Indian equivalent
* [[Yu-7 torpedo#Yu-11|Yu-11 torpedo]] - Chinese equivalent
* [[Chung Sang Eo|K745 Chung Sang Eo]] - South Korean equivalent
* [[Type 97 light weight torpedo (G-RX4)]] - Japanese equivalent
* [[Torped 47]] — Swedish equivalent
* [[Copperhead (UUV)|Copperhead-100M]], an autonomous unmanned undersea loitering munition comparable in size and capability to the Mark 54.

==References==
{{Reflist}}

==External links==
{{Commons category|Mark 54 torpedo}}
*[http://www.fas.org/man/dod-101/sys/ship/weaps/mk-54.htm MK-54 Lightweight Hybrid Torpedo] via FAS
*[http://www.deagel.com/pandora/mark-54_mn00206001.aspx MK-54] at deagel.com

{{Raytheon}}
{{Mark-series torpedoes}}
{{Use dmy dates|date=June 2017}}

[[Category:Torpedoes of the United States]]
[[Category:Aerial torpedoes]]
[[Category:Raytheon Company products]]
[[Category:Military equipment introduced in the 2000s]]