A minesweeper is a small warship tonnage using a dredge, mechanical, acoustic or magnetic towed in an area likely to be undermined:
- Mechanical dredging is to shear the tether mine to make contact to the surface and destroy the light gun or rifle.
- Dredging influence is to detonate mines magnetic influence and / or acoustic triggers their firing.
Unlike minesweeper, the dredger does not detect mines.
Dredging operations are particularly dangerous. Dredgers are built accordingly:
- magnetic immunization: wooden construction, use of bronze and aluminum, immunization loops;
- reduced acoustic signature;
- good resistance to shocks underwater explosions.
Nonetheless, sweepers are vulnerable, which is why inFranceminesweeping to influences, magnetic and acoustic conducting “behind” (behind the dredger) and not “plumb” (under the dredger) since the 1960s.
During the First Worldtrawlers modified to tow a mechanical dredge, instead of a trawl fishing were the first minesweepers. Minesweepers designed as such were built during the period between the wars, but at the beginning of , many navies, including the French navy, still using many trawlers mobilized equipped for mechanical dredging. It was only during the war as the specialized units in the fight against magnetic influence mines, acoustic, or both combined, came into service.
In terms of shipbuilding, the “golden age” of minesweepers is located between 1950 and 1970.
The development of electronic fire put mine made minesweeping much less effective. Most navies have therefore replaced by the minesweeper minesweeper.
In the early 1960s, the Navy had 101 minesweepers, funded mostly by NATO under the Mutual Assistance Plan. Of minesweepers manufactured in theUnited States(15 Type MSO), the coastal minesweepers built also in theUnited States(30 Type MSC),Canada(6 Type MSC), and France (34 types and 1 D DB) and finally sweepers shallow (15 type MSI), built inBritain.
Several minesweepers (MSO), some of which have been recast as minesweepers and coastal minesweepers built French (D), have devoted their careers to mine warfare. Many have been “further engagement” (in reserve “mothballed”) or transferred to allied navies. Others were assigned to patrol missions inFranceand overseas. Finally some sweepers shallow (MSI) were used as training ship for sea legs pupils of the school foam and school petty officers and several coastal minesweepers (MSC) were trained to conduct marine officers Navy petty officers and sailors, even in the 1990s.
French Navy no longer has a minesweeper, but eleven Tripartite minesweepers Eridan class are equipped with a mechanical dredge lightly to neutralize moored mines, equipment that did not have the first five hunters mines Circe class, contemporary and complementary minesweepers, and sold to the Turkish Navy where they are still in service.
Dredgers “D” Class Sirius
If in the early 1960s, the French Navy had 101 inits fleet minesweepers, the majority were of foreign origin (United States, Britainand Canada). Only 34 coastal minesweepers type D Class Sirius (plus three built for the Yugoslav Navy), and a coastal minesweeper DB, Mercury (six built for the Navy Federal Republic of Germany) were built in France from 1952 to 1956, the arsenal of Cherbourg and in private yards. They were commissioned between 1954 and 1958. All these units had names of stars or constellations.
They were designed by the vehicle manufacturer British Thornycroft and quite similar to class minesweepers Tone Britishand the Koninklijke Marine Dokkum theNetherlands, where sometimes the name of Scoundrels “typeWestern Europe.”
These buildings were grouped in divisions of organically Scoundrels (DIDRA) three to five units. The squadron dredging (Ezra) was based inCherbourgand the second Ezra, inBrest. None has been based inToulon. Overseas, two buildings were stationed atFort-de-FranceandDakar.
Features: To reduce the magnetic signature, they were equipped with circuitry immunization. The hull and deck were wood, duralumin frames and superstructures marine plywood and aluminum alloy.
Machines: 21 were propelled by two free-piston generators Sigma-Pescara, and 13 by two Pielstick diesel engines of the same power SEMT.
Their maximum speed on the road was free and mechanical dredging in magneto-acoustic dredging. They had two three-bladed propellers fixed except for M734, M735, M736 and M737 whose propellers were not variables.
- 21 dredgers “Pescara” M701 Sirius (1952-1971), M702 Rigel (1953-1974), M703 Antares (1953-1981), M704 Algol (1953-1976), M705 Aldebaran (1953-1970), M706 Regulus (1952 -1974), M707 Vega (1953-1981), M708 Castor (1953-1973), M709 Pollux (1953-1970), M740 Cassiopeia (1953-1976), M741 Eridan renamed Aldebaran in 1977 (1953-1979), Orion M742 (1953-1970), M743 Sagittarius (1953-1979), M744 Achernar (1953-1970), M745 Procyon (1953-1970), 1955-1974 Pegasus M710), M750 Bellatrix (1955-1974), M751 Denebola (1955 – 1974), M752 Centaur (1955-1970), M753 Fomalhaut (1955-1970).
- 13 dredgers “Pielstick” M746 Arcturus (1954-1981), M747 Betelgeuse (1954-1989), M754 Canopus (1955-1982), M749 Phoenix (1955-1992), M755 Capella (1955-1987), M759 Cepheus (1956 -1988), M757 Aquarius (1956-1988), M758 Ariès (1956-1988), M759 Lyre (1956-1981), M734 Southern Cross (1956-1981), M735 Polar Star (1956-1978), M736 Altair ( 1956-1982), M737 Capricorn (1956-1988).
Staff: they were usually commanded by a lieutenant. Their crew (before repyramidage Degrees 1974) was three officer s, eight petty officers and twenty-eight quartermasters and sailor s. These were housed in two positions each with fourteen crew bunks instead of hammocks s, a novelty at that time, on military ships of French construction.
Dredging equipment: D dredges dredges were equipped with mechanical, magnetic, acoustic and dredge explosive.
- Mechanical dredge: Able to cut the tether mine to contact these dredges were type Oropesa (OD1). The strands were armed with drag cutters, explosives or not. It was possible to dredging coupled to two or more dredgers.
- Magnetic sweep: at the beginning of their careers, they were equipped with dredges symmetrical loops MB1, MB3 MB4 and. In 1960, dredging by acoustic lagging, they received dredges MB5 asymmetrical loop which was deployed to starboard. The power of the dredge was provided by a magnetic power generator.
- Drag acoustic first dredges equipped with aplomb (AM1, AO1, AP1). This type of dredging is too dangerous because the mine could explode the shell, they were equipped with dredges behind AM1 and AP1 modified extruded port. The reel power cable was installed on the roof of drag behind the chimney, instead of gun.
- Explosive drag: drag AE1 was intended to influence the acoustic mines.
: their origin consisted of a gun Beaufort on the beach front and a gun Oerlikon drag on the roof, then a single gun from 1960, on the beach front. The stationary overseas (M734, M736, M746 and M754) had retained their original weapons as being used as patrol, they had not been changed for dredging noise behind.
Conclusion: With Mercury, 34 minesweepers D Class Sirius were the first and last minesweepers built in France capable of both mechanical dredging and dredging magneto-acoustic influences. In construction, a bunker was scheduled for a screening device asdic, but the following was never installed. They were gradually replaced from 1970 by five minesweepers (MSO) in the Revised Dompaire class mine hunters and in 1972 by commissioning five minesweepers class Circe.
Some “mothballed”, which were removed from the lists of the fleet in 1970, had an active career rather short. Others, based in La Pallice used to monitor field fire test center Landes (CEL) off Biscarrosse, from 1964 to 1981. It was draggers gas turbines “Pescara”, mechanics fragile. The draggers Pielstick Diesels, more reliable, have a career much longer and operational mine warfare patrol or as overseas. The Phoenix is one who has served the longest. Reclassified Patrol Cherbourg, it was decommissioned in 1992 after 37 years of service.