The Maginot Line (English: ; French: ligne Maginot [liɲ maʒino]) is a line of concrete fortifications, obstacles and weapon installations built by France in the 1930s. Named after the French Minister of War André Maginot, it was constructed on the French side of its borders with Italy, Switzerland, Germany, Luxembourg and Belgium. The line was to deter invasion by Nazi Germany and force them to move around the fortifications through Belgium. It was impervious to most forms of attack, but in 1940 the Germans invaded through the Belgian Ardennes, immediately to the north, just beyond the end of the main line of fortifications. Based on France's experience with trench warfare during World War I, the massive Maginot Line was built before the Second World War, after the Locarno Conference in 1925 gave rise to a fanciful and optimistic "Locarno spirit". French military experts believed the line would deter German aggression because it would slow an invasion force long enough for French forces to mobilise and counter-attack. The line was supposed to be extended along the French frontier with Belgium, but was not built in response to demands from Belgium. Belgium feared it would be sacrificed in the event of another German invasion. The French planned to advance heavily into Belgium in response to a German invasion of Belgium, meeting German forces on Belgian territory, but in the event, the Ardennes invasion allowed the Germans to outflank the French forces that advanced into Belgium. The Maginot Line was invulnerable to aerial bombings and tank fire and used underground railways for movement. It had modern living conditions for the garrison, with air conditioning and eating areas for their comfort. French and British officers had anticipated the geographical limits of the Maginot Line; when Germany invaded the Netherlands and Belgium, they carried out the Dyle plan to form a front along the Dyle in Belgium to connect with the Maginot Line. The French line was weak near the Ardennes. General Maurice Gamelin, when drafting the Dyle Plan, believed this region, with its rough terrain, would be an unlikely invasion route by German forces; if it were traversed, it would be done at a slow rate that would allow the French time to bring up reserves and counter-attack. The German Army, having altered their plans when it became known to the Allies in the Mechelen incident on 10 January 1940, redirected the effort against this weak point in the French defensive front. The Manstein plan replaced the original plan with a gamble that the main German armoured force could cross the Ardennes and cross the Meuse before the Allies could react. The Germans crossed the Meuse and raced down the Somme river valley, encircled much of the Allied forces in the north, leading to the Dunkirk evacuation and leaving the troops to the south unable to mount an effective resistance to the Germans. The Maginot Line has since become a metaphor for expensive efforts that offer a false sense of security.
== Purposes == The Maginot Line was built to fulfill several purposes:
To prevent a German surprise attack. To deter a cross-border assault. To protect Alsace and Lorraine (returned to France in 1918) and their industrial basin. To save manpower (France counted 39 million inhabitants, Germany 70 million). To slow an attack to permit the mobilisation of the French Army (which took between two and three weeks). To push Germany into an effort to circumvent via Switzerland or Belgium, and allow France to fight the next war off French soil to avoid a repeat of 1914–1918. To be used as a basis for a counter-offensive.
Personnel
Maginot Line fortifications were manned by specialist units of fortress infantry, artillery and engineers. The infantry manned the lighter weapons of the fortresses and formed units with the mission of operating outside if necessary. Artillery troops operated the heavy guns, and the engineers were responsible for maintaining and operating other specialist equipment, including all communications systems. All these troops wore distinctive uniform insignia and considered themselves among the elite of the French Army. During peacetime, fortresses were only partly manned by full-time troops. They would be supplemented by reservists who lived in the local area and who could be quickly mobilised in an emergency. Full-time Maginot Line troops were accommodated in barracks built close to the fortresses. They were also accommodated in complexes of wooden housing adjacent to each fortress, which were more comfortable than living inside, but were not expected to survive wartime bombardment. The training was carried out at a fortress near the town of Bitche in Moselle in Lorraine, built in a military training area and so capable of live fire exercises. This was impossible elsewhere as the other parts of the line were located in civilian areas.
Organisation
Although the name "Maginot Line" suggests a relatively thin linear fortification, it was 20–25 kilometres (12–16 miles) deep from the German border to the rear area. It was composed of an intricate system of strong points, fortifications and military facilities such as border guard posts, communications centres, infantry shelters, barricades, artillery, machine-gun and anti-tank-gun emplacements, supply depots, infrastructure facilities and observation posts. These various structures reinforced a principal line of resistance made up of the most heavily armed ouvrages, which can be roughly translated as fortresses or big defensive works.
=== Border post line === This consisted of blockhouses and strong-houses, which were often camouflaged as residential homes, built within a few metres of the border and manned by troops to give the alarm in the event of a surprise attack and to delay enemy tanks with prepared explosives and barricades.
=== Outpost and support point line === Approximately 5 km (3 mi) behind the border there was a line of anti-tank blockhouses that were intended to provide resistance to armoured assault, sufficient to delay the enemy and allow time for the crews of the C.O.R.F. ouvrages to be ready at their battle stations. These outposts covered the main passages within the principal line.
=== Principal line of resistance === This line began 10 km (6 mi) behind the border. It was preceded by anti-tank obstacles made of metal rails planted vertically in six rows, with heights varying from 0.70–1.40 metres (2 ft 4 in – 4 ft 7 in) and buried to a depth of 2 m (6 ft 7 in). These anti-tank obstacles extended from end to end in front of the main works, over hundreds of kilometres, interrupted only by extremely dense forests, rivers, or other nearly impassable terrains. The anti-tank obstacle system was followed by an anti-personnel obstacle system made primarily of dense barbed wire. Anti-tank road barriers also made it possible to block roads at necessary points of passage through the tank obstacles.
=== Infantry casemates === These bunkers were armed with twin machine-guns (abbreviated as JM — Jumelage de mitrailleuses — in French) and anti-tank guns of 37 or 47 mm (1.5 or 1.9 in). They could be single (with a firing room in one direction) or double (two firing rooms in opposite directions). These generally had two floors, with a firing level and a support/infrastructure level that provided the troops with rest and services (power-generating units, reserves of water, fuel, food, ventilation equipment, etc.). The infantry casemates often had one or two "cloches" or turrets located on top of them. These GFM cloches were sometimes used to emplace machine guns or observation periscopes. 20 to 30 men manned them.
=== Petits ouvrages === These small fortresses reinforced the line of infantry bunkers. The petits ouvrages were generally made up of several infantry bunkers, connected by a tunnel network with attached underground facilities, such as barracks, electric generators, ventilation systems, mess halls, infirmaries and supply caches. Their crew consisted of between 100 and 200 men.
Gros ouvrages
These fortresses were the most important fortifications on the Maginot Line, having the sturdiest construction and the heaviest artillery. These were composed of at least six "forward bunker systems" or "combat blocks" and two entrances and were connected via a network of tunnels that often had narrow gauge electric railways for transport between bunker systems. The blocks contained infrastructure such as power stations, independent ventilating systems, barracks and mess halls, kitchens, water storage and distribution systems, hoists, ammunition stores, workshops and spare parts and food stores. Their crews ranged from 500 to more than 1,000 men.
=== Observation posts === These were located on hills that provided a good view of the surrounding area. Their purpose was to locate the enemy, direct and correct the indirect fire of artillery, and report on the progress and position of critical enemy units. These are large reinforced buried concrete bunkers, equipped with armoured turrets containing high-precision optics, connected with the other fortifications by field telephone and wireless transmitters (known in French by the acronym T.S.F., Télégraphie Sans Fil).
=== Telephones === This system connected every fortification in the Maginot Line, including bunkers, infantry and artillery fortresses, observation posts and shelters. Two telephone wires were placed parallel to the line of fortifications, providing redundancy in case a wire was cut. There were places along the cable where dismounted soldiers could connect to the network.
=== Infantry reserve shelters === These were found from 500–1,000 m (1,600–3,300 ft) behind the principal line of resistance. These were buried concrete bunkers designed to house and shelter up to a company of infantry (200 to 250 men). They had amenities such as electric generators, ventilation systems, water supplies, kitchens and heating, which allowed their occupants to hold out in the event of an attack. They could also be used as a local headquarters and counterattack base.
Flood zones
Flood zones were natural basins or rivers that could be flooded on demand and thus constitute an additional obstacle in the event of an enemy offensive.
=== Safety quarters === These were built near the major fortifications so fortress (ouvrage) crews could reach their battle stations in the shortest possible time in the event of a surprise attack during peacetime.
=== Supply depot and Ammunition dumps === Supply depot and ammunition dumps were built around 50 km (30 mi) away from the Maginot Line. Supplies were transported to the Maginot Line by a railway system.
=== Narrow-gauge railway system === A network of 600 mm (1 ft 11+5⁄8 in) narrow-gauge railways was built to rearm and resupply the main fortresses (ouvrages) from supply depots up to 50 km (31 mi) away. Petrol-engine armoured locomotives pulled supply trains along these narrow-gauge lines. (A similar system was developed with armoured steam engines in 1914–1918.)
=== High-voltage transmission lines === Initially above-ground but then buried, and connected to the civil power grid, these provided electric power to the many fortifications and fortresses.
=== Heavy rail artillery === This was hauled by locomotives to planned locations to support the emplaced artillery in the fortresses, which was intentionally limited in range to 10–12 km (6–7 mi).
Inventory
Ouvrages
There are 142 ouvrages, 352 casemates, 78 shelters, 17 observatories and around 5,000 blockhouses in the Maginot Line.
=== Armoured cloches === There are several kinds of armoured cloches. Cloches are non-retractable turrets. The word cloche is a French term meaning bell due to its shape. All cloches were made of alloy steel.
The most widespread are the GFM cloches, where GFM means Guetteur fusil-mitrailleur (machine-gun sentry). They are composed of three to four openings, called crenels or embrasures. These crenels may be equipped as follows: light machine-guns, direct vision blocks, binoculars blocks or 50 mm (2.0 in) mortars. Sometimes, the cloche is topped by a periscope. There are 1,118 GFM cloches on the line. Almost every block, casemate and shelter is topped by one or two GFM cloches. The JM cloches (jumelage de mitrailleuses or "twin machine guns") are the same as the GFM cloches except that they have one opening equipped with a pair of machine guns. There are 174 JM cloches on the line. There are 72 AM cloches (armes mixtes or "mixed weapons") on the line, equipped with a pair of machine guns and a 25 mm (1.0 in) anti-tank gun. Some GFM cloches were transformed into AM cloches in 1934. (The aforementioned total does not include these modified cloches.) There are 75 LG cloches (lance-grenade or "grenade launcher") on the line. Those cloches are almost completely covered by concrete, with only a small hole to launch grenades through for local defence. There are 20 VP cloches (vision périscopique or "periscopic vision") on the line. These cloches could be equipped with several different periscopes. Like the LG cloches, they were almost entirely covered by concrete. The VDP cloches (vision directe et périscopique or "direct and periscopic vision") are similar to the VP cloches but have two or three openings to provide a direct view. Consequently, they were not covered by concrete.
=== Retractable turrets === The line included the following retractable turrets.
21 turrets of 75 mm (3.0 in) model 1933 12 turrets of 75 mm (3.0 in) model 1932 1 turret of 75 mm (3.0 in) model 1905 17 turrets of 135 mm (5.3 in) 21 turrets of 81 mm (3.2 in) 12 turrets for mixed weapons (AM) 7 turrets for mixed weapons + mortar of 50 mm (2.0 in) 61 turrets of machine-guns
=== Artillery === Both static and mobile artillery units were assigned to defend the Maginot Line. Régiments d'artillerie de position (RAP) consisted of static artillery units. Régiments d'artillerie mobile de forteresse (RAMF) consisted of mobile artillery.
=== Anti-tank guns === Canon de 25 mm SA Mle1934 SA-L Mle1937 (Puteaux) L/72 AC 37 AC 47
History
=== Prelude === In January 1923, after Weimar Germany defaulted on reparations, the French Premier, Raymond Poincaré, sent French troops to occupy the Ruhr. During the Ruhrkampf (Ruhr struggle) between the Germans and the French that lasted until September 1923, Britain condemned the Occupation of the Ruhr. A period of sustained Francophobia broke out in Britain, with Poincaré being vilified in Britain as a bully, punishing Germany with unreasonable reparations demands. The British—who openly championed the German position on reparations—applied intense economic pressure on France to change its policies towards Germany. At a conference in London in 1924 to settle the Franco-German crisis caused by the Ruhrkampf, the British Prime Minister, Ramsay MacDonald, persuaded the French Premier, Édouard Herriot, to make concessions to Germany. The British diplomat, Sir Eric Phipps, who attended the conference, commented afterwards that
The London Conference was for the French 'man in the street' one long Calvary as he saw M. Herriot abandoning one by one the cherished possessions of French preponderance on the Reparations Commission, the right of sanctions in the event of German default, the economic occupation of the Ruhr, the French–Belgian railway Régie and finally, the military occupation of the Ruhr within a year. The great conclusion that was drawn in Paris after the Ruhrkampf and the 1924 London Conference was that France could not make unilateral military moves to uphold Versailles as British hostility to such moves was too dangerous to the republic. Beyond that, the French were well aware of the contribution of Britain and its dominions to the victory of 1918. French leaders believed they needed Britain's help to win another war; the French must appease the British. From 1871, French elites had concluded that France had no hope of defeating Germany on its own, and France would need an alliance with another great power to prevail.
=== Allied Control Commission === In 1926, The Manchester Guardian ran an exposé showing the Reichswehr had been developing military technology forbidden by the Treaty of Versailles in the Soviet Union. The secret German–Soviet cooperation started in 1921. The German statement following The Manchester Guardian's article that Germany did not feel bound by the terms of Versailles and would violate them as much as possible gave much offence in France. In 1927, the Inter-Allied Commission, which was responsible for ensuring that Germany complied with Part V of the Treaty of Versailles, was abolished as a goodwill gesture, reflecting the "Spirit of Locarno". When the Control Commission was dissolved, the commissioners in their final report issued a condemnation, that Germany had never sought to abide by Part V and the Reichswehr had been engaging in covert rearmament all through the 1920s. Under the Treaty of Versailles, France was to occupy the Rhineland region of Germany until 1935. Still, the last French troops left the Rhineland in June 1930 in exchange for Germany accepting the Young Plan. As long as the French occupied the Rhineland, it served as a type of collateral under which the French would annexe the Rhineland in the event of Germany breaching any of the articles of the treaty, such as rearmament; this threat was powerful enough to deter German governments all through the 1920s from attempting any overt violation of Part V. French plans as developed by Marshal Ferdinand Foch in 1919 were based on the assumption that in the event of a war with the Reich, the French forces in the Rhineland were to embark upon an offensive to seize the Ruhr. A variant of the Foch plan had been used by Poincaré in 1923 when he ordered the French occupation of the Ruhr.
=== French planning === French plans for an offensive in the 1920s were realistic, as Versailles had forbidden German conscription, and the Reichswehr was limited to 100,000 men. Once the French forces left the Rhineland in 1930, this form of leverage with the Rhineland as collateral was no longer available to Paris, which from then on had to depend on Berlin's word that it would continue to abide by the terms of the Versailles and Locarno treaties, which stated that the Rhineland was to stay demilitarised forever. Given that Germany had engaged in covert rearmament with the co-operation of the Soviet Union starting in 1921 (a fact that had become public knowledge in 1926) and that every German government had gone out of its way to insist on the moral invalidity of Versailles, claiming it was based upon the so-called Kriegsschuldlüge (war guilt lie) that Germany started the war in 1914, the French had little faith that the Germans would willingly allow the Rhineland's demilitarised status to continue forever, and believed that at some time in the future, Germany would rearm in violation of Versailles, reintroduce conscription and remilitarise the Rhineland. The decision to build the Maginot Line in 1929 was a tacit French admission that without the Rhineland as collateral, Germany was soon going to rearm and that the terms of Part V had a limited lifespan.
=== German economy === After 1918, the German economy was twice as large as that of France; Germany had a population of 70 million compared to France's 40 million, and the French economy was hobbled by the need to reconstruct the enormous damage of World War I, while German territory had seen little fighting. French military chiefs were dubious about their ability to win another war against Germany without allies, especially an offensive war. French leaders knew that the victory of 1918 had been achieved because Russia, the British Empire and the United States were allies in the war and that the French would have been defeated on their own. With the United States isolationist and Britain stoutly refusing to make the "continental commitment" to defend France on the same scale as in World War I, the prospects of Anglo-American assistance in another war with Germany appeared to be doubtful at best. Versailles did not call for military sanctions in the event of the German military reoccupying the Rhineland or breaking Part V, while Locarno committed Britain and Italy to come to French aid in the event of a "flagrant violation" of the Rhineland's demilitarised status, it did not define what a "flagrant violation" would be. The British and Italian governments refused in diplomatic talks to define "flagrant violation", which led the French to place little hope in Anglo–Italian help if German military forces should reoccupy the Rhineland. Given the diplomatic situation in the late 1920s, the Quai d'Orsay (Ministry of Foreign Affairs) informed the government that French military planning should be based on a worst-case scenario that France would fight the next war against Germany without the help of Britain or the United States. France had an alliance with Belgium and with the states of the Cordon sanitaire, as the French alliance system in Eastern Europe was known. Although the alliances with Belgium, Poland, Czechoslovakia, Romania and Yugoslavia were appreciated in Paris, it was widely understood that this was no compensation for the absence of Britain and the United States. The French military was especially insistent that the population disparity made an offensive war of manoeuvre and swift advances suicidal, as there would always be far more German divisions; a defensive strategy was needed to counter Germany. The French assumption was always that Germany would not go to war without conscription, which would allow the German Army to take advantage of the Reich's numerical superiority. Without the natural defensive barrier provided by the Rhine River, French generals argued that France needed a new defensive barrier made of concrete and steel to replace it. The power of properly dug-in defensive trenches had been amply demonstrated during World War I, when a few soldiers manning a single machine gun post could kill hundreds of the enemy in the open and therefore building a massive defensive line with subterranean concrete shelters was the most rational use of French manpower. The American historian, William Keylor, wrote that in the diplomatic conditions of 1929 and likely trends – with the United States isolationist and Britain unwilling to make the "continental commitment" – the decision to build the Maginot Line was not irrational and stupid but a sensible response to the problems that would be created by the coming French withdrawal from the Rhineland in 1930. Part of the rationale for the Maginot Line stemmed from the severe French losses during the First World War and their effect on the French population. The drop in the birth rate during and after the war, resulting in a national shortage of young men, created an "echo" effect on the generation that provided the French conscript army in the mid-1930s. Faced with a manpower shortage, French planners had to rely more on older and less fit reservists, who would take longer to mobilise and would diminish French industry because they would leave their jobs. Static defensive positions were therefore intended to delay a German invasion and to economise on men by defending an area with fewer and less mobile forces. In 1940, France deployed about twice as many men, 36 divisions (roughly one third of its force), for the defence of the Maginot Line in Alsace and Lorraine. In contrast, the opposing German Army Group C only contained 19 divisions, fewer than a seventh of the force committed in the Manstein Plan for the invasion of France. Reflecting memories of World War I, the French General Staff had developed the concept of la puissance du feu ("the power of fire"), the power of artillery dug in and sheltered by concrete and steel, to inflict devastating losses on an attacking force.
=== Long war strategy === French planning for war with Germany was always based on the assumption that the war would be la guerre de longue durée, a long attritional war, in which the superior economic resources of the Allies would gradually grind the Germans down. The fact that the Wehrmacht embraced the strategy of Bewegungskrieg (war of manoeuvre) with the vision of swift wars in which Germany would win quickly via a knockout blow was a testament to the fundamental soundness of the concept of la guerre de longue durée. Germany had the largest economy in Europe but lacked many of the raw materials necessary for a modern industrial economy, making the Reich vulnerable to blockade and the ability to feed its population. The guerre de longue durée strategy called for the French to halt the expected German offensive, denying the Germans a swift victory; afterwards, there would be an attrition struggle; once the Germans were exhausted, France would begin an offensive to win the war. The Maginot Line was intended to block the main German blow if it should come via eastern France and divert it through Belgium, where French forces would meet and stop the Germans. The Germans were expected to fight costly offensives, whose failures would sap the strength of the Reich, while the French waged a total war, mobilising the resources of France, its empire and allies. Besides the demographic reasons, a defensive strategy served the needs of French diplomacy towards Great Britain. The French imported a third of their coal from Britain and 32 per cent of all imports through French ports were carried by British ships. Of French trade, 35 per cent was with the British Empire and the majority of the tin, rubber, jute, wool and manganese used by France came from the British Empire. About 55 per cent of overseas imports arrived in France via the Channel ports of Calais, Le Havre, Cherbourg, Boulogne, Dieppe, Saint-Malo and Dunkirk. Germany had to import most of its iron, rubber, oil, bauxite, copper and nickel, making naval blockade a devastating weapon against the German economy. For economic reasons, the success of the strategy of la guerre de longue durée would at the very least require Britain to maintain a benevolent neutrality, preferably to enter the war as an ally as British sea power could protect French imports while depriving Germany of hers. A defensive strategy based on the Maginot Line was an excellent way of demonstrating to Britain that France was not an aggressive power and would only go to war in the event of German aggression, a situation that would make it more likely that Britain would enter the war on France's side.
