Fortified Sector of Montmédy

The Fortified Sector of Montmédy (Secteur Fortifié de Montmédy) was the French military organization that in 1940 controlled the section of the Maginot Line between Sedan and Longuyon, a distance of about 60 kilometres (37 mi). The sector was not as strongly defended as other sections of the Maginot Line, facing the southern Ardennes region of Belgium. Large portions of the Montmédy sector were defended by fortified houses, blockhouses, or casemates. The sector includes only four ouvrages of the type found in stronger sections of the Line. The weakly defended area in front of Sedan was the scene of a major breakthrough by German forces in the opening of the Battle of France. This was followed by a German assault on the Maginot Ouvrage La Ferté, which killed the entire garrison, the only such event on the Maginot Line.

The sector was created in 1940 as part of the reorganization of the Meuse Front, which was combined with the Maginot Montmédy Bridgehead (Tête du Pont de Montmédy) and the Defensive Sector of Marville, itself separated from the Fortified Sector of the Crusnes. As a result, the fortifications in the new sector represent a wide variety of types and degrees of fortification. The Sedan sub-sector comprises two distinct lines, with fortified houses close to the border and a line of blockhouses along the line of the Meuse. The houses were built in 1938 by the Military Works organization (Main d'Oeuvre Militaire (MOM)), while the blockhouses were built primarily by the Army Engineer Service (Service Technique du Génie (STG)), beginning in 1936. The Mouzon sub-sector was organized similarly. A number of blockhouses were built to local designs, such as the FCR or Billotte blocks of the Sedan sub-sector.

The fortified houses took the form of a blockhouse on the ground floor with a light residential superstructure providing living quarters for the crew manning the blockhouse. Their armament consisted principally of light arms fired from a number of firing ports and embrasures, augmented by light anti-tank weapons. Fortified houses were sited close to the frontier, typically in a location that commanded the cross-border road. Blockhouses were plain concrete structures, providing little to nothing in the way of living quarters for their crews. Blockhouses typically displayed the rounded edges and shielded firing positions characteristic of artillery casemates and combat blocks of the Maginot ouvrages built by CORF (Commission d'Organisation des Régions Fortifiées), the Maginot Line's design and construction agency, but were usually built under non-CORF direction. Casemates tended to be built by CORF as part of the integrated Maginot defenses, and frequently mounted heavier weapons, of up to 75mm caliber. Both casemates and blockhouses could have infantry cloches or cupolas for observation and protected small-arms fire.

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