A
minesweeper is a small
naval warship designed to counter the threat posed by
naval mines. Minesweepers generally detect then neutralize mines in advance of other naval operations. The dedicated, purpose-built minesweeper first appeared during
World War I with the
Flower-class minesweeping sloop.
Operation and requirements
Minesweepers are equipped with mechanical or influence sweeps to detonate 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,
glass-reinforced plastic (GRP) or
non-ferrous metal, or is
degaussed to reduce its
magnetic signature.
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. The most common such sweeps are magnetic and acoustic generators.
There are two modes of operating an influence sweep: MSM (mine setting mode) and TSM (target setting mode or target simulation 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 through the area. TSM sweeping thus clears mines directed at this ship without knowledge of the mines. However, mines directed at other ships might remain.
The minesweeper differs from a
minehunter; the minehunter actively detects and neutralises 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. The first such ship was
HMS Wilton, also the first warship to be constructed from
glass-reinforced plastic.
Minesweeping aircraft
thumb|upright|A MH-53E towing the MK105 mine sweeping sled Aircraft can also be used for minesweeping. During World War II, fifteen
British Vickers Wellington bombers were modified to carry a large
magnetic induction loop and an
electrical generator. The 'Directional Wireless Installation' (DWI), a cover story for the true purpose of the magnetic loop, was used successfully on May 10 1940 to sweep a path for the escape of the
Dutch Royal Family to the UK. The DWI was used most successfully in the
Mediterranean theatre, particularly over the
Suez Canal and
Alexandria Harbour. Their use revealed the limitations of the technique, in that it only works effectively in very shallow water (such as canals and harbours). From about 1943,
German Junkers Ju 52 transports were similarly converted.
The
MH-53E Sea Dragon helicopter, which tows a minesweeping sled, is used by the
United States Navy for minesweeping.
Notable minesweepers
- HMS Wilton – the first combined MCMV and the first warship constructed from GRP
See also
