Fortified Sector of Colmar

The Fortified Sector of Colmar (Secteur Fortifié de Colmar) was the French military organization that in 1940 controlled the section of the French frontier with Germany in the vicinity of Colmar. The fortifications were built as part of France's Maginot Line defensive strategy, but the sector lacks the large interconnected fortifications found along France's land border with Germany. The sector's principal defense was the Rhine itself, which could be crossed only by boat or by seizing a bridge crossing. The sector's fortifications chiefly took the form of casemates and blockhouses. The SF Colmar was flanked to the north by the Fortified Sector of the Lower Rhine to the north and the Fortified Sector of Mulhouse to the south. The Colmar sector was directly attacked by German forces on 15 June 1940, capturing or destroying most of the fortifications in the sector in three days.

The Maginot Rhine defenses employed three lines of defense, with blockhouses or casemates close to the Rhine (the first line), backed by infantry shelters (the second line). The third line was a strong series of casemates, built on the model of interval casemates in the northeastern sections of the Line, but without lower levels. All of the Colmar fortifications were built in the mid-1930s by the Commission d'Organisation des Régions Fortifiées (CORF). CORF was responsible for the major fortifications of the Maginot Line, but in this area no major positions or ouvrages were built.

The riverbank fortifications were of a basic nature, with protection only up to 155mm caliber, machine gun armament and no electrical system. The second and third lines were more robust in construction and equipment, with electric generators and anti-tank weapons. The heaviest concentration of fortifications were in the area of Neuf-Brisach, itself a preserved fortress from the Vauban era. Neuf-Brisach guarded a strategic bridge across the Rhine.

The Colmar sector was under the overall command of the French 8th Army, which was in turn part of Army Group 3 under General Besson. The SF Colmar was commanded by General Coradin, then General Poisot and finally General Cousse from 1 January 1940. The command post was at Colmar. The interval troops, the army formations that were to provide the mobile defense for the sector, to support and be supported by the fixed defenses, were under the command of the 13th Corps (13e Corps d'Armee), General Misserey, commander. The primary interval formation was the 54th Infantry Division. Artillery support for the sector was provided by the first battalion of the 170th Position Artillery Regiment (Régiment d'Artillerie de Position (RAP)), which controlled both fixed and mobile artillery, commanded by Chef d'Escadron Maigret. The 54th ID was a Class B reserve formation, not suitable for sustained or heavy combat.

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