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France - Chasseur de Mines

The coasts of France are long (3000 km) and access to certain key ports could easily be denied by judiciously placed mines. The continental shelf extends out some 150 km from the coasts, with depths favorable to the use of this type of weapon. Minesweeping operations pursued for several years following the 1939-1945 war in order to eliminate the danger of some 10,000 mines laid by the Germans or the British have confirmed the effective limits of the mineswpeer and the need to deploy them in large numbers. At the beginning of the 1970s there still remained almost 9000 bottom mines in our coastal waters. The frigate LAPLACE indeed sank in 1956 and a number of fishing boats have still been disappearing these last few years for having unfortunately trawled one of these devices.

All of these reasons militate in favor of the Navy's interest in minehunting. At the same time, a new need is arising. With implementation of the Strategic Ocean Force, it had become absolutely necessary to be able to assure transit of our submarines within our coastal waters in complete safety. A surveillance of the seabeds became obligatory, and who better than the minehunter could assure this mission?

The guiding thought of this evolution is the following: to have a good knowledge of the seabeds (their nature and dimensions) in such a way as to be able to establish and clean up the areas most favorable to minehunting or those necessary for the operation of our forces, and then to assure surveillance of such zones with a minimum of effort. To do this, it would be necessary to devise a weapon system which could detect and pinpoint a suspicious object on the seabed, classify it, identify it, then initiate an action with a view to either neutralizing it if it turns out to be a new or unknown device, or destroying it if it should turn out to be a known but dangerous object.

On 15 November 1950, off the coast of Korea, a major multinational naval force, primarily composed of American ships, was preparing, against the background of the war which was raging in that area, to execute a landing. This operation, known as the Inchon landing, was not without its vicissitudes. One of these had as a goal the entry into Wonson, the key port on the west coast, protected by fields of ingenuously set magnetic mines. Several weeks were required to sweep them. The lucky find by a commando, set ashore, who discovered in a barn an example of the circuits utilized, left behind by the enemy, greatly facilitated the work.

The waters were clear and the mines were visible from the helicopters and this caused grumbling by the Command which did not appreciate the fact that, knowing their location, they could not be eliminated. This vicissitude of the Korean War was the origin of the interest which prompted American operational authorities, and later certain European navies, into studies directed at locating mines on the sea bed with the help of an acoustic sensor.

Thus the United States launched during the 1950s a program involving fleet minesweepers provided with, in addition to conventional minesweeping gear, a sonar called the AN/UQS-1/D, which permitted, under certain conditions, detection on the sea bed of metallic objects. Utilizing this gear proved difficult due to innumerable echos causea by the heterogeneity of the water, the differences in the nature of the sea bed, as well as by all the objects and rocks strewn about.

France acquired a few of these ships starting in 1955 through the Offshore programs, but it was necessary to wait until the mid-1960s before the operational authorities recognized, in view of positive exercise results, the real advantage of this sonar. During the same time, French engineers, interested in the problem and sustained by the zeal exhibited by the archives officers of the Commission on Practical Studies on Mine Warfare (C.E.P.G.M.) were engaging in promising studies which were leading to an improvement in the system.

During this time, the Korean War having been forgotten, the United States, having known the danger of mine warfare only through operations outside of its territorial waters, did not feel the need to maintain a mine countermeasures force along its coasts. After having somewhat improved its sonar owing to a VDS version (veriable-depth sonar), the AN/USQ-14, it abandonned its research in this area.

From the Minesweeper to the CIRCE-Class Minehunter

Since the AN/US-1/D sonar of the oceanic minesweepers permits only detection, it was necessary to send for a team of mineclearing divers to handle classification, identification, all together. It is with the purpose of improving this situation that French engineers viewed their work and culminated their research toward the end of the 1960s.

The DUBH 20 sonar, springing from the imagination of the technicians at GESMA (Groupe dtetude sous-marine de l'Atlantique: Atlantic Underwater Research Groups an organization belonging to DCAN (Direction des Constructions et Armes Navales: Bureau of Naval Construction and Weapons) and the engineers of the CSF company (later Thomson CSF) was a crucial step in the development of minehunting. Provided with 2 separate sonars, it consolidated the functions of detection and classification. Linked with the self-propelled PAP 104 fish industrialized by ECA (Establissement Cineratographique des Armies: Armed Forces Cinematographic Establishment) allowing identification at both a distance and in situ by means of a television camera, it became the SKUBERMOR I weapon system ("sea sweep" in Breton) very well thought of among the world's navies.

Between 1969 and 1972,this system was installed on a series of five minehunters of the CIRCE Class, constructed by the Amiot Shipyard of Cherbourg (CMN = Constructions Mecanique de Normandie - Normandy Mechanical Construction). The quality of the weapon system was such that by way of example, the hunt record of the CALLIOPE, as of 01 January 1981, was not less than 180 mines, and various other marine objects or obstructions as attested to in the photo above.

During the 1970s, major missions were carried out, in particular during the cleanup of the Suez Canal after the Six-Day War, or again within the framework of the development of its autonomous ports of France, like Le Havre-Antifer. For these ports to receive deep-draft vessels it was necessary to clear the approach channels of all obstructions. In other cases it was necessary to dredge in order to deepen the channels: before undertaking these works, the local authorities made an appeal to the Navy and its minehunters in order to have the assurance that there were no remaining mines from the last war which could greatly disrupt operations. This was the case for the works undertaken for the opening of the Gironde by the autonomous port of Bordeaux-Le Verdon.

From the CIRCE Class to the DOMPAIRE Class

During this time French minesweeping forces were aging, and it was evident that the five minehunters were not sufficient for the task. France had the weapon system, it remained to find a platform. The solution was reached by utilizing the best preserved hulls of the fleet minesweepers and refitting them by installing in them the SKUBERMOR weapon system, which was done between 1975 and 1979. Frane then benefited from an improvement in the weapon system, first on the sonar, the bulkiness of the antennas of which was greatly reduced, and the modes of operation modified, and then the associated localization systems.

It appeared progressively evident from the use of the CIRCE minehunters that a good knowledge of the sea beds required a very precise positionof the detected echos. This precision, tested at 10 m, is very hard to obtain, numerous sources of error being able to Intervehe. It is within this perspective that studies carried on with the SINDRA Company since the commissioning of the CIRCE Class resulted in a plotting board with automatic data processing. This device, known as EVEC (Ensemble de visuallsation et enregistrement en chasse aux mines: Minehunting display and recording assembly) was first integrated into the SKUBERMOR system on the CIRCE Class, and afterwards linked with the DUBMA ZIA sonar, thus giving the SKUBERMOR system of the DOMPAIRE Class its second generation.

Thus the functions of localization, automatic processing and magnetic tape recording of data represent the basic evolution of the capacities of French minehunters between 1974 and 1979. The former fleet minesweeper NARVIK and the coastal minesweeper BETELGEUSE, experimental ships attached to the Center for Studies, Instruction, and Training in Mine Warfare (C.E.T.I.E.G.M.) were deployed for this purpose. This organization, founded in 1976 and including under its jurisdiction the Commission on Practical Studies (C.E.P.G.M.), works in very close coordination with the engineers of GESMA.

ERIDAN-Class CMT (Contre-Mine Tripartite)

The minehunter became the backbone of the mine countermeasures forces, but by itself it is vulnerable. That is why the first tactic is, and will remain for a rather long time, to utilize conjointly in a single operation the minesweeper and the minehunter, one protecting the other. At the present time, the deployment of our ships responds to this requirement. French mine countermeasures forces were going to be, with the arrival of the ERIDAN-Class CMT (Contre-Mine Tripartite: tripartite mine countermeasures), greatly strengthened. Simultaneously, the mine menace will continue to grow. Although France had the impression of having attained a technological plateau is the search for mines by sonar, it was certainly necessary to progress and continue to adapt equipment and tactics.

Many ERIDAN-Class CMT (Contre-Mine Tripartite) were units assigned to port breakout for the SSBN fleet at Brest.

The war of the mines participates in all the missions of the navy. Mine warfare units are tasked with specificized threats, are able to maintain simultaneous access to a port of vital interest (PIV), and are ready to ensure free access to Allied ports. They are also intended to be projected within a national or inter-allied naval force when operations are carried out near coasts that are more sensitive to "mines" risk. The threat is also incarnated in the so-called "historical" explosive devices (mines, shells, bombs), a legacy of past conflicts, of which we can only have an approximate appreciation.

To participate in these missions, by 2012 the Naval Action Force included:

  • 11 mine-hunters equipped with the equipment necessary for the identification of equipment placed on the bottom and for their destruction;
  • 3 groups of demining divers (GPDs) operating up to 80 meters deep and able to board aboard demining diversion bases (Mediterranean-Atlantic-Channel);
  • towing vessels for surveillance of the approaches to Brest;
  • a test building;
  • a command and support vessel.

The war of the mines consists of 15 major annual exercises, between 80 and 90 machines destroyed per year (by "machine", a mine of the second world war or dropped bombs of aircraft) and destruction by the grouping of the divers Deminers, of 3 tons of explosive materials.






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