The Maginot Line was conceived as a self-contained system, eventually consisting of two distinct geographic regions. The main part of the line protected Alsace-Lorraine along the Rhine frontier. The Thionville-Metz region was the most heavily fortified and included the huge Hackenberg fortress, with more than 6 miles of underground galleries separated into sectors by heavy antiblast doors, connecting 17 combat blocks. Less known even today was what some sources call the Little Maginot Line. This line protected the French Alpine provinces facing Italy, including important mountain passes, with about 25 miles of continuing fortification down to the Mediterranean at Menton. One of these forts, Rimplas, was the first of the entire system to be built, beginning in 1928.
In each region, the Maginot Line was made up of advance posts, major forts, support facilities, and lines of communication—all built to a standard plan and widely dispersed to withstand modern artillery attack. Located 3 to 6 miles behind the frontier, major ( gros) and smaller ( petit) infantry or artillery forts ( ouvrages) were built to make effective use of terrain to control transportation routes. Artillery pieces—mortars and howitzers—were especially designed for Maginot Line use and were housed in huge casemates, some with retractable turrets. (The largest howitzers were 134 mm caliber weapons.) Each fort had its own diesel power supply and storage deep underground. The largest forts were served by up to a thousand men able to operate for a month at a time, moved from one part of a fort to another by underground electric trains ( métro). Forts were located in positions that gave troops the ability to fire on their neighbors to fend off surface enemy attacks (which did not happen at Eben Emael) without harming the occupants (casemate reinforced concrete was more than 10 feet thick and then further protected with many feet of earth). Command-and-control facilities were often buried 60 or more feet deep, relying on input from fortified observation cupolas, an extensive buried telephone network, and radio links. All entrances (usually one for provisions and another for men) were heavily fortified, featured retractable drawbridges (or lifting bridges), and were made airtight against gas attack. There were also emergency entrances for all forts.
What did the Germans know of the Maginot Line before the war? Actually, they knew quite a bit, much of it learned from the captured Czech border forts that were closely modeled on Maginot examples. Aerial surveys just before the war, spies, and interviews with many who had helped to construct the forts (some of them Germans!) gave the German military a good sense of where the Maginot Line forts were and what they could offer in resistance. The Germans did begin work in 1937 on the Gustav gun, with the intention of using it to crack the Maginot Line.
The Germans were also well aware of the fatal flaw in the Maginot Line's geographic conception. Persuaded that no sizable military force could penetrate the dense Ardennes Forest region of southern Belgium, the line of forts stopped at that point, and only light fortifications (dubbed the Maginot Extension) were built along the Belgian frontier to the English Channel. The French plan was to advance into Belgium and assist their allies at the Belgian border fortresses. The plan depended on having enough time to move the requisite armies.
When the German attack finally came in May 1940, of course, blitzkrieg tactics did not provide that time. Guderian's panzers and infantry broke through the Ardennes and turned the flank of the Maginot Line while other forces drove toward the Channel, cutting off British forces. The French, who could barely advance, were rapidly overwhelmed by the German onslaught.
German attacks never breached the structures of any of the gros ouvrages, though some of the smaller outlying facilities were taken in fierce fighting because the surface forces supporting them had been withdrawn. And despite the German use of huge siege mortars and cannon, no major fort fell. Indeed, the Germans took only a few petit ouvrages on the far western end, even though they expended considerable effort and usually greatly outnumbered the defenders. To the south, the Italians never broke through the Alpine defenses, although they did directly assault the gros ouvrage of Cap Martin overlooking the sea in a failed attempt to gain control of the coast road.
In the end, the Maginot Line accomplished exactly what it was designed to do—protect Alsace-Lorraine and the French provinces facing Italy. It did not "fail," despite the fact that some of its forts had not yet been fully armed. The existence of the line, originally designed to give the army time to mobilize and then attack, had clearly lulled France into complacency in the face of a rearming Germany and Italy. The French army fell into a defensive stance and ignored mobile warfare, as the High Command was convinced the line could contain any enemy attack. Only after the Germans occupied two-thirds of the nation did Maginot Line forces surrender with the rest of France.
Forces stationed at many of the forts (e.g., Hackenberg and Simershoff) fought again in 1944 as the Allies neared the German frontier, and some of the fortifications were heavily damaged as they had not been in 1940. After the war, the French reoccupied and partially rearmed the Maginot Line, maintaining some forts into the 1960s; then, they were finally abandoned for good. A few facilities, such as a part of Hochwald, are still used by the French army or air force, generally for storage or communications. A number of ouvrages have been opened as museums; others are used to grow mushrooms or store wine. The rounded cement outlines of Maginot casemates will stand out against the terrain for decades to come. Christopher H. Sterling
Kaufmann, J. E., and H. W. Kaufmann. The Maginot Line: None Shall Pass. Westport, CT: Praeger, 1997.; Kaufmann, J. E., and J. M. Jurga. Fortress Europe: European Fortifications of World War II. Conshohocken, PA: Combined Publishing, 1999, pp. 11–58.; Kaufmann, Joseph E. "The Maginot Line—German Intelligence before the War." Fort 26 (1998): 199–231.; Kemp, Anthony. The Maginot Line: Myth & Reality. Briarcliff Manor, NY: Stein and Day, 1982.; Mallory, Keith, and Arvid Ottgar. The Architecture of War. New York: Pantheon, 1973, pp. 90–107.; Rolf, Rudi, and Peter Saal. Fortress Europe. Shrewsbury, UK: Airlife, 1986.; Rowe, Vivian. The Great Wall of France: The Triumph of the Maginot Line. London: G. P. Putnam, 1959.; Truttmann, Philippe. La Muraille de France, Ou La Ligne Maginot. Thionville, France: Gerard Klopp, 1996.
Christopher H. Sterling