View source for Minesweeper

{{short description|Vessel for locating and removing naval mines}}
{{other uses}}
[[Image:The Royal Navy during the Second World War A14421.jpg|thumb|right|upright=1.15|Minesweeper [[MMS-class minesweeper|''J 636'']] underway in British coastal waters during [[World War II]]]]
A '''minesweeper''' is a small [[warship]] designed to remove or detonate [[naval mine]]s. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping.<ref>{{cite book|title=The Oxford Essential Dictionary of the U.S. Military|year=2012|publisher=Oxford University Press |location=Oxford|isbn=9780199891580|url=http://www.oxfordreference.com/view/10.1093/acref/9780199891580.001.0001/acref-9780199891580-e-5170?rskey=RQ9uw5&result=1&q=minesweeper| chapter=minesweeper}}</ref>

==History==
The earliest known usage of the [[naval mine]] dates to the [[Ming dynasty]].<ref name="needham volume 5 part 7 203 205">Needham, Volume 5, Part 7, 203–205.</ref> Dedicated minesweepers, however, only appeared many centuries later during the [[Crimean War]], when they were deployed by the British. The Crimean War minesweepers were rowboats trailing [[Grappling hook|grapnel]]s to snag mines.  Minesweeping technology picked up in the [[Russo-Japanese War]], using aging [[torpedo boat]]s as minesweepers.

[[File:Minesweeper cutting loose moored mines diagram 1952.jpg|thumb|A minesweeper cutting loose moored mines]]

In Britain, naval leaders recognized before the outbreak of [[World War I]] that the development of sea mines was a threat to the nation's shipping and began efforts to counter the threat. Sir Arthur Wilson noted the real threat of the time was a blockade aided by mines and not an invasion. The function of the fishing fleet's trawlers with their trawl gear was recognized as having a natural connection with mine clearance and, among other things, [[Naval trawler|trawlers]] were used to keep the [[English Channel]] clear of mines.<ref>{{cite book|last=Bacon|first=Sir Reginald|title=The Dover patrol 1915-1917|year=1919|publisher=G. D. Doran co.|pages=146|url=https://play.google.com/store/books/details?id=ceBCAAAAIAAJ&rdid=book-ceBCAAAAIAAJ&rdot=1}}</ref> A Trawler Section of the [[Royal Navy Reserve]] became the predecessor of the mine sweeping forces with specially designed ships and equipment to follow. These reserve Trawler Section fishermen and their trawlers were activated, supplied with mine gear, rifles, and uniforms, and paid as the first minesweepers.<ref>{{cite book |last= Hawkins |first= Nigel |title= The Starvation Blockades: Naval Blockades of WW1 |publisher= U.S. Naval Institute Press |pages= 60–61 |year= 2003 |isbn= 0-85052-908-5}})</ref> The dedicated, purpose-built minesweeper first appeared during [[World War I]] with the [[Flower-class sloop|Flower-class minesweeping sloop]].  By the end of the War, naval mine technology had grown beyond the ability of minesweepers to detect and remove mines.<ref name=OUPmaritime>{{cite book|last=Hattendorf|first=John B.|title=The Oxford encyclopedia of maritime history|year=2007|publisher=Oxford Univ. Press|location=Oxford|isbn=9780195130751|url=http://www.oxfordreference.com/view/10.1093/acref/9780195130751.001.0001/acref-9780195130751-e-0543?rskey=BUX7jj&result=1&q=minesweeper}}</ref>

Minesweeping made significant advancements during [[World War II]].  Combatant nations quickly adapted ships to the task of minesweeping, including Australia's 35 civilian ships that became [[Auxiliary motor minesweepers|auxiliary minesweepers]].<ref>{{cite book|last=Dennis|first=Peter|title=The Oxford companion to Australian military history.|year=2012|publisher=Oxford University Press|location=South Melbourne, Vic.|isbn=9780195517842|url=http://www.oxfordreference.com/view/10.1093/acref/9780195517842.001.0001/acref-9780195517842-e-149?rskey=tP17bb&result=12&q=minesweeper|edition=2nd|author2=Jeffrey Grey |author-link2=Jeffrey Grey  |author3=Ewan Morris |author4=Robin Prior |author5=Jean Bou |chapter=Auxiliary Minesweepers}}</ref>  Both Allied and Axis countries made heavy use of minesweepers throughout the war.  Historian Gordon Williamson wrote that "Germany's minesweepers alone formed a massive proportion of its total strength, and are very much the unsung heroes of the [[Kriegsmarine]]."<ref>{{cite book|last=Williamson|first=Gordon|title=Kriegsmarine Coastal Forces|year=2012|publisher=[[Osprey Publishing]]|isbn=9781782000006|pages=48|url=https://books.google.com/books?id=CEvHjyugb3MC}}</ref>  Naval mines remained a threat even after the war ended, and minesweeping crews were still active after [[Victory over Japan Day|VJ Day]].<ref>{{cite journal|title=Sweeping up sudden death|journal=Popular Mechanics|date=January 1946|volume=85|issue=1|pages=28–34|editor1-first=Roderick M.|editor1-last=Grant|issn=0032-4558}}</ref>
After the Second World War, Allied countries worked on new classes of minesweepers ranging from 120-ton designs for clearing [[estuary|estuaries]] to 735-ton oceangoing vessels.<ref>{{cite book|last=Jane's|title=Jane's War at Sea 1897-1997: 100 Years of Jane's Fighting Ships|year=1997|publisher=HarperCollins|pages=224|url=https://books.google.com/books?id=dkDkTc56w8MC|edition=100|access-date=15 October 2012|chapter=Mine Countermeasures|isbn=9780004720654}}</ref>  The [[United States Navy]] even used specialized [[Landing Craft Mechanized|mechanized landing craft]] to sweep shallow harbors in and around [[North Korea]].<ref>{{cite journal|last=Dempewolff|first=Richard F.|title=Mother of the minesweepers|journal=Popular Science|date=February 1952|volume=97|issue=2|pages=97–104|url=https://books.google.com/books?id=8dwDAAAAMBAJ|access-date=15 October 2012|editor1-first=Roderick M.|editor1-last=Grant|publisher=Hearst Magazines|issn=0032-4558}}</ref>

{{As of|2012|June}}, the [[United States Navy|U.S. Navy]] had four minesweepers deployed to the Persian Gulf to address regional instabilities.<ref>{{cite news|last=Cavas|first=Christopher P.|title=U.S. doubling minesweepers in Persian Gulf|url=http://www.navytimes.com/news/2012/03/dn-us-doubling-minesweepers-in-persian-gulf-031512/|access-date=15 October 2012|newspaper=[[NavyTimes]]|date=March 15, 2012}}</ref><ref>{{cite news|title=Four U.S. Navy minesweepers arrive in the Gulf|url=https://www.reuters.com/article/gulf-navy-mines-idUSL5E8HP1CQ20120625|access-date=15 October 2012|newspaper=Reuters|date=25 June 2012}}</ref> The Royal Navy also has four minesweepers stationed in the Persian Gulf as part of the [[9th Mine Counter-Measures Squadron]].

==Operation and requirements==
<!-- [[MSM]] links to this section -->
[[File:Magneettiraivain.jpg|thumb|Magnetic naval minesweeper as a monument in [[Kotka]], [[Finland]]]]
[[Image:M1098 Siegburg.jpg|thumb|right|''Siegburg'', a modern {{sclass|Ensdorf|minesweeper|1}} of the [[German Navy]]]]
Minesweepers are equipped with mechanical or electrical devices, known as "sweeps", for disabling mines. The modern minesweeper is designed to reduce the chances of it detonating mines itself; it is [[soundproofing|soundproofed]] to reduce its [[acoustic signature]] and often [[hull (ship)|constructed]] using wood, [[fiberglass]], or [[non-ferrous metal]], or is [[degaussing|degaussed]] to reduce its [[magnetism|magnetic signature]].<ref name=HowItWorks>{{cite book|title=How it works : science and technology.|year=2003|publisher=Marshall Cavendish|location=New York|isbn=0-7614-7333-5|pages=2633|url=https://archive.org/details/howitworks12mars|url-access=registration|edition=3rd|access-date=15 October 2012|chapter=Minesweepers}}</ref>

Mechanical sweeps are devices designed to cut the anchoring cables of moored mines, and preferably attach a tag to help the subsequent localization and neutralization. They are towed behind the minesweeper and use a towed body (e.g., [[Oropesa (minesweeping)|oropesa]], [[Paravane (weapon)|paravane]]) to maintain the sweep at the desired depth and position. Influence sweeps are equipment, often towed, that emulate a particular ship signature, thereby causing a mine to detonate. 

There are two modes of operating an influence sweep: MSM (mine setting mode) and TSM (target simulation mode or target setting mode). MSM sweeping is founded on intelligence on a given type of mine, and produces the output required for detonation of this mine. If such intelligence is unavailable, the TSM sweeping instead reproduces the influence of the friendly ship that is about to transit the area. TSM sweeping thus clears mines directed at this ship without knowledge of the mines. However, mines directed at other ships might remain.<ref>Dick Linssen and Åshild Bergh (2000): "Target Simulation Mode Mine Sweeping - SWEEPOP", pamphlet, 4 pages, [[Netherlands Organisation for Applied Scientific Research|TNO]] Physics and Electronics Laboratory, The Netherlands.</ref><ref>P A Brodtkorb, B-E Marthinsen, M Nakjem, R Fardal (2005): "Royal Norwegian Navy (RNoN) introduces new mine sweeping capabilities", Undersea Defence Technology (UDT) Europe, conf. proc., Amsterdam.</ref>

The minesweeper differs from a [[minehunter]]; the minehunter actively detects and neutralizes individual mines. Minesweepers are in many cases complementary to minehunters, depending on the operation and the environment; a minesweeper is, in particular, better suited to clearing open-water areas with large numbers of mines. Both kinds of ships are collectively called [[mine countermeasure vessel]]s (MCMV), a term also applied to a vessel that combines both roles.
[[File:Базовые тральщики проекта 1265.png|thumb|Basic minesweepers of project 1265. USSR]]

==See also==
* [[List of minesweeper classes]]
* [[Demining]]
* [[Destroyer minesweeper]]
* [[Minehunter]]
* [[List of mine warfare vessels of the United States Navy]]
* [[List of mine countermeasure vessels of the Royal Navy]]
* [[List of mine warfare vessels of the Second World War]]

==References==
{{reflist}}

==Further reading==
* Bruhn, David D.. (2006). ''Wooden Ships and Iron Men: The U.S. Navy's Ocean Minesweepers, 1953-1994''. Heritage Books. {{ISBN|978-0-7884-3260-6}}.
* Bruhn, David D.. (2009). ''Wooden Ships and Iron Men: The U.S. Navy's Coastal and Motor Minesweepers, 1941-1953''. Heritage Books. {{ISBN|0-7884-4909-5}}.
* Lund & Ludlam. (1978) ''Out Sweeps! The Story of the Minesweepers in World War II''.  Foulsham/New English Library  {{ISBN|0450044688}}.  Minesweeping by the wartime Royal Navy.

==External links==
{{Commons category|Minesweepers}}
* [https://web.archive.org/web/20070111091835/http://www.pewteraircraft.com/RAF/WELLINGTON%20DWI/Wellington%20DWI.htm Pewter Aircraft | Vickers Wellington DWI of 1 GRU used to clear magnetic mines]
* [http://www.mahu880.nl Ex HNLMS M880 - Mahu  - MSI] (Dutch)
* [http://www.minsveparen.se Swedish Minesweeper from 1941 M 20 webpage still operational]
* [https://books.google.com/books?id=VCcDAAAAMBAJ&dq=popular+science+may+1941&pg=PA102 "Fighting The Submarine Mine - How Navies Combat A Deadly Sea Weapon" October 1941]

{{MARCOMships}}
{{WWII US ships}}
{{Warship types of the 19th & 20th centuries}}
{{Authority control}}

[[Category:Minesweepers| ]]
[[Category:Ship types]]