A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. [1]
The earliest known usage of the naval mine dates to the Ming dynasty. [2] 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 grapnels to snag mines. Minesweeping technology picked up in the Russo-Japanese War, using aging torpedo boats as minesweepers.
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, trawlers were used to keep the English Channel clear of mines. [3] 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. [4] The dedicated, purpose-built minesweeper first appeared during World War I with the 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. [5]
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 minesweepers. [6] 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." [7] Naval mines remained a threat even after the war ended, and minesweeping crews were still active after VJ Day. [8] After the Second World War, Allied countries worked on new classes of minesweepers ranging from 120-ton designs for clearing estuaries to 735-ton oceangoing vessels. [9] The United States Navy even used specialized mechanized landing craft to sweep shallow harbors in and around North Korea. [10]
As of June 2012 [update] , the U.S. Navy had four minesweepers deployed to the Persian Gulf to address regional instabilities. [11] [12] The Royal Navy also has four minesweepers stationed in the Persian Gulf as part of the 9th Mine Counter-Measures Squadron.
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 soundproofed to reduce its acoustic signature and often constructed using wood, fiberglass, or non-ferrous metal, or is degaussed to reduce its magnetic signature. [13]
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, 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. [14] [15]
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 vessels (MCMV), a term also applied to a vessel that combines both roles.
A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry or anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered.
A minehunter is a naval vessel that seeks, detects, and destroys individual naval mines. Minesweepers, on the other hand, clear mined areas as a whole, without prior detection of mines. A vessel that combines both of these roles is known as a mine countermeasures vessel (MCMV).
Minesweeping is the practice of removing explosive naval mines, usually by a specially designed ship called a minesweeper using various measures to either capture or detonate the mines, but sometimes also with an aircraft made for that purpose. Minesweeping has been practiced since the advent of naval mining in 1855 during the Crimean War. The first minesweepers date to that war and consisted of British rowboats trailing grapnels to snag the mines.
The Ton class were coastal minesweepers built in the 1950s for the Royal Navy, but also used by other navies such as the South African Navy and the Royal Australian Navy. They were intended to meet the threat of seabed mines laid in shallow coastal waters, rivers, ports and harbours, a task for which the existing ocean-going minesweepers of the Algerine class were not suited.
HMS Kirkliston (M1157) was a Ton-class minesweeper of the Royal Navy, built by Harland and Wolff and launched on 18 February 1954. In a brief episode from 1956 to 1960 she was temporarily renamed HMS Kilmorey and was assigned to the Ulster division Royal Naval Reserve (RNR).
An oropesa is a streamlined towed body used in the process of minesweeping. The role of the oropesa is to keep the towed sweep at a determined depth and position from the sweeping ship. Oropesa are standard devices used on Avenger-class mine countermeasures ships.
Destroyer minesweeper was a designation given by the United States Navy to a series of destroyers that were converted into high-speed ocean-going minesweepers for service during World War II. The hull classification symbol for this type of ship was "DMS." Forty-two ships were so converted, beginning with USS Dorsey (DD-117), converted to DMS-1 in late 1940, and ending with USS Earle (DD-635), converted to DMS-42 in mid-1945. The type is now obsolete, its function having been taken over by purpose-built ships, designated as "minesweeper (high-speed)" with the hull classification symbol MMD.
A mine countermeasures vessel or MCMV is a type of naval ship designed for the location of and destruction of naval mines which combines the role of a minesweeper and minehunter in one hull. The term MCMV is also applied collectively to minehunters and minesweepers.
The Tripartite class is a class of minehunters developed from an agreement between the navies of Belgium, France and the Netherlands. A total of 35 ships were constructed for the three navies. The class was constructed in the 1980s–1990s in all three countries, using a mix of minehunting, electrical and propulsion systems from the three member nations. In France, where they are known as the Éridan class they are primarily used as minehunters, but have been used for minesweeping and ammunition transport in Belgium and the Netherlands, where the Tripartites are known as the Alkmaar class.
The River class was a class of minesweeper built for the British Royal Navy in the 1980s, designated Fleet Minesweepers (MSF). Operated mainly by the Royal Naval Reserve they were taken out of service in 1990s and sold to foreign navies.
HMS Berkeley was a Hunt-class mine countermeasures vessel of the British Royal Navy. She was sold to the Hellenic Navy in 2001 and was commissioned as HS Kallisto. On 27 October 2020, she was cut in two in a collision with a container ship.
USS Auk (AM-38) was a Lapwing-class minesweeper acquired by the United States Navy after World War I to remove mines that had been placed during the war.
USS Leader (AM-490/MSO-490) was an Agile-class minesweeper acquired by the U.S. Navy for the task of removing mines that had been placed in the water to prevent the safe passage of ships.
The Royal Naval Patrol Service (RNPS) was a branch of the Royal Navy active during both the First and Second World Wars. The RNPS operated many small auxiliary vessels such as naval trawlers for anti-submarine and minesweeping operations to protect coastal Britain and convoys.
Avenger-class mine countermeasures ships are a class of 14 ships constructed for the United States Navy from 1987 to 1994, designed to clear mines from vital waterways. The ships have the hull designator MCM.
Operation End Sweep was a United States Navy and United States Marine Corps operation to remove naval mines from Haiphong harbor and other coastal and inland waterways in North Vietnam between February and July 1973. The operation fulfilled an American obligation under the Paris Peace Accord of January 1973, which ended direct American participation in the Vietnam War. It also was the first operational deployment of a U.S. Navy air mine countermeasures capability.
HMS Brereton (M1113) was a Ton-class minesweeper of the Royal Navy. Brereton was built by the Lowestoft shipbuilder Richard Ironworks, and was launched in 1953 and entered service in 1954.
The Fleet-class unmanned surface vessel, also called the Common Unmanned Surface Vessel (CUSV) and later the Mine Countermeasures Unmanned Surface Vehicle, is an unmanned surface vessel designed for the United States Navy to be deployed from Freedom and Independence-class littoral combat ships and intended to conduct mine and anti-submarine warfare missions. As of 2012 four units of the class have been built; the first was delivered to the U.S. Navy in 2008.
Junella was a fishing trawler, best known for her service with the Royal Navy during the Falklands War. She was built in 1975 for J Marr & Son, a Hull-based fishing company. On 11 April 1982 she was taken up from trade by the British government and commissioned into the Royal Navy. She was fitted with Second World War era minesweeping gear at Rosyth Dockyard, manned by Royal Navy sailors and allocated to the 11th Mine Countermeasures Squadron. She sailed on 26 April but was unable to commence sweeping until after the 14 June Argentine surrender. In the meantime she was utilised to transfer troops and stores between ships and landed special forces troops at San Carlos. Demining operations commenced on 21 June. Junella returned to the United Kingdom on 11 August, carrying a defused Argentine mine.