The Maginot Line is a system of French fortifications on the border with Germany from Belfort to Longillon. It was built in 1929-1934 (then improved until 1940). The length is about 400 km. Named after the Minister of War Andre Maginot. It included 39 long-term defensive fortifications, 70 bunkers, 500 artillery and infantry units, 500 casemates, as well as dugouts and observation posts.
The French assumed that the Germans would act in the same way as in 1914 - they would try to bypass the French troops through Belgium from the northeast. Therefore, their defense plan involved repelling a German attack on the Dyle River and passive defense on the fortified Maginot Line.
About 3 billion francs ($1 billion in prices of those years) were spent on the construction of the Maginot Line. The total number of troops on the line reached 300 thousand people. The underground multi-level forts were equipped with living quarters for personnel, power plants, powerful ventilation units, narrow-gauge railways, telephone exchanges, hospitals, rest rooms, inaccessible to shells and bombs.
On September 1, 1939, Germany attacks Poland and on September 3, France declares war on Germany, from that day mobilization takes place and the fort is filled with soldiers who will leave it only in June 1940 after the surrender of France. Until May 10, 1940, the period of the “Phantom War” lasted, during which both sides: Germany and France sat behind their lines of fortifications and large-scale hostilities were not conducted. After the Germans broke through the Maginot Line in the Saar region, fighting began in this region, but despite powerful attacks by the Germans with artillery support, the fort was never captured and remained undefeated. After the surrender of France on June 25, 1940, the soldiers of the fort were forced to surrender on honorable terms by order of the French High Command. A few days later, the fort PO Rohrbach was handed over to the Germans and its defenders were sent to one of the prisoner of war camps.
04. German soldiers near the second block in 1940.
photo: http://www.fortcasso-maginot.com
05. Second block in our time. The hole with a grille in the foreground is the air intake of the ventilation system, iron fittings with wire stretched between them are radio communication antennas. Near the entrance there is a machine gun embrasure, which was supposed to prevent the enemy from approaching close to the block. In front of the walls of the block there is a so-called diamond ditch, the main purpose of which was to receive fragments of concrete from the walls and roof in the event of an air bombardment of the fort. In this way, blocking the exit from the fort with concrete debris was avoided. The bridge spanning the diamond ditch was removed inside when the fort was closed. This door is the only entrance to the fort, apart from the emergency exit tunnel.
The German army did not use the fort either in 1940 or in the fight against Allied forces in 1944-45. Thanks to this, the fort was not damaged and was perfectly preserved in almost its original condition. In 1951, many forts of the Maginot Line, including Fort Rohrbach, were modernized and put on combat readiness due to the emergence of a new potential enemy - the Warsaw Bloc. But after the French created their nuclear weapons, the defensive structures of the Maginot Line finally lost their relevance and in 1970 Fort Rohrbach was withdrawn from the army. In 1987, activists from local residents, with the support of the city of Rohrbach-les-Bitche, began to restore the fort, and in 1989 the association "Fort Casso" was created, the goal of which was to restore the fort to its pre-war condition and open it to the public.
06. American troops near the second block in 1944. 
photo: http://www.fortcasso-maginot.com
That's all about the history of the fort. Now a few words about the structure of the fort. All Maginot Line forts have the same structure and consist of a certain number of combat blocks (3-4 blocks for small forts and up to two dozen blocks for the largest forts of the defensive line), connected by underground tunnels (poterns). In addition, underground there are barracks for accommodating personnel, a kitchen, a power plant, a hospital, a command post, signalmen's quarters, warehouses for provisions, fuel and ammunition. In essence, the fort was a small underground city, capable of holding its defense for two months, remaining completely autonomous. The depth of the underground part of Fort Rohrbach is 25 meters. This is a safe depth to which it was impossible to penetrate by explosive means, even if bombed in the same place. The fact is that the most powerful bomb of the time when the Maginot Line was built left a crater six meters deep. The second bomb, dropped into the crater from the first, penetrated not six meters, but much less. Thus, it was impossible to break through to a depth of 25 meters using weapons of that time.
The picture below, although not related to this fort, gives an excellent idea of what the combat block of the Maginot Line fort and its underground system look like.
source: www.lignemaginot.com
The diagram of the small fort PO Rohrbach is shown in the figure below. As can be seen from the diagram, the fort consists of three combat blocks connected by turns, several hundred meters long. The fort has one main entrance located in the second block. In addition to the main one, there is also an emergency exit, which is located at the end of the adit, which originates near the third block. The length of this adit can be several hundred meters, or maybe a kilometer or even more. The entire underground part of the fort (barracks, kitchen, warehouses, power plant) is concentrated near the second entrance block. In total, 182 people served at Fort PO Rohrbach: 6 officers and 176 ordinary soldiers.
07. Well, let's now go inside and see what it all really looks like.
08. Machine gunner’s position with a MAS 24/29 machine gun built into the embrasure, guarding the entrance to the fort. If the entrance armored door is blown up and the enemy begins to storm the fort, the first thing he will stumble upon is the barrel of a machine gun.
09. In the next room there is a filter and ventilation unit. On the filters you can see the year they were installed in the fort - 1939.
10. The second block is equipped with two armored domes: the first is a GFM dome, I wrote about this type of dome in previous posts dedicated to the structures of the Maginot Line. The second dome is AM type (Arme Mixte). This is how they look from the outside (AM in the foreground, GFM in the background):
11. An observation armored cap of the GFM type, familiar to us from previous posts. It could be equipped with optics for observation; if necessary, a MAS 24/29 light machine gun or a 50-mm caponier mortar was built into the embrasure. The thickness of the cap armor is 300 mm, the weight of the GFM armored cap is 26 tons.
12. And this is the AM type armored cap shaft. Here the equipment looks more impressive.
13. The AM type armored cap was equipped with a combined weapon consisting of a machine gun and a 25-mm anti-tank gun. This is the most impressive type of armored cap used at Maginot Line facilities. The weight of the armored cap reached up to 50 tons.
14. The combined weapon from this armored cap is displayed nearby for clarity.
15. Behind the next armored door there is an elevator shaft and a spiral staircase going around it downwards. Only officers or other high-ranking visitors to the fort had the right to use the elevator; soldiers walked. In addition to the officers, the elevator transported food and ammunition to the lower level. This is the fort's only elevator. The elevator cabin could accommodate eight people or a ton of cargo and was equipped with a stopper in case of a break in the supporting cable.
16. We go down underground along the stairs that go around the elevator shaft fenced with bars. There are 145 steps leading underground.
17. The underground level of Fort PO Rohrbach lies at a depth of 25 meters in limestone soil - this is approximately the height of a nine-story building.
18. Numerous communications between the underground part of the fort and the surface.
19. So we reached a depth of 25 meters, from this place my acquaintance with the fascinating underground world begins.
20. Immediately opposite the elevator there is a small storage room with various small household items. This room served as an intermediate warehouse, where the elevator could be quickly unloaded and sent for a new batch of cargo. During hostilities, the premises also served as a morgue. But in the entire history of the fort, only one soldier died here, patrolling the area around the fort and stumbling upon a German reconnaissance detachment.
21. To get shots without people, I walked at the very end of the tour, so some of the photos turned out looking back. Behind the door in the photo is the elevator lifting mechanism.
Let's return once again to the fort diagram. I have drawn a red oval around the part of the fort that I will show in this post. Immediately next to the stairs and the elevator there is a kitchen; opposite it is an energy center, which includes transformers for converting high-voltage current received from the outside via a power cable, as well as an autonomous power station consisting of two diesel generators. Next are the soldiers' barracks and officers' quarters, the infirmary, the command center and the warehouse part of the fort, which houses a small museum with various weapons and equipment of the fort. The diagram also shows the appendix of an unfinished postern, which was supposed to lead to another combat block, but due to funding cuts, this block was never built, and the postern was filled in before the war.
Now let’s examine the entire underground part of the fort in the listed sequence.
22. The closest room to the elevator shaft is the kitchen. Where people are visible in the photo is the exit from where we started the underground walk. That is, the photo was taken with the back to the turn leading further into the fort.
23. Living for months in a confined space in a bunker is psychologically very difficult. Therefore, in order to maintain the morale and vigor of personnel, the nutrition of soldiers was given a special role. The food in the bunkers of the Maginot Line was much better than on the surface. The best chefs were brought into the bunkers and the kitchen was equipped with the latest technology of the time. Much of the kitchen equipment installed in the Maginot Line forts did not appear in ordinary apartments until decades later.
24. All the equipment in the kitchen, including the ovens, was electric. The large silver box on the right side of the photo is a coffee maker.
25. And this amazing device peeled potatoes. Thus, the soldiers were freed from their potato peeling duties. Everything in this fort was designed to make life underground as easy as possible.
26. This is the high-tech kitchen of the mid-30s.
27. Behind the kitchen there are several closets, in one of them there are hooks for meat carcasses.
28. In another there is equipment, the purpose of which could not be determined. Possibly some kind of refrigeration unit.
29. Window for issuing food to soldiers.
30. A characteristic feature of the Maginot Line forts was the absence of dining rooms. Each soldier received his own food and ate it either on his bed or at these tables displayed right in the fort's walls. In the photo below, the tables are located right next to the kitchen.
31. And this is the turna, going to the other two combat blocks. Here we also see tables with benches along the underground passage.
32. Immediately opposite the kitchen there is a power station with backup diesel generators. Let's take a look there.
33. Stylish diesel punk is everywhere here. The door in the center of the frame leads into a room with huge fuel tanks.
34 In case of damage to the power cable feeding the fort, a local power station consisting of two SMIM (Paris) engines was built in one of the premises.
35. Both engines are four-cylinder, developing 100 hp. at 600 rpm. Thanks to low speed operation, the engines were very reliable.
36. Electrical panel.
37. In this corner of the power station, under the floor, there is a well, 250 meters deep, from which the entire fort is supplied with water using an electric pump located under the floor. The photo on the right shows part of the pumping equipment for transporting water from the well to the fort's reservoirs.
38. This is what the entire power plant room looks like.
39. The engines are quite impressive in their appearance and size.
40. In the corner of the power plant hall there is a small workshop, which had everything needed to fix minor malfunctions in the operation of equipment.
41. Tool.
42. Workshop.
43. Each of the engines was connected to an alternating electric current generator. The huge engines were started using compressed air, which was supplied to two of the four cylinders in order to drive a driveshaft with a huge and heavy flywheel. After the engine accelerated, the stationary operating mode with fuel injection was switched on. Tanks with compressed air necessary for starting diesel engines are visible in the photo on the left.
44. At the output there is another single-cylinder engine with a small generator, possibly a backup one. The inspection of the power plant is over and we return to the main area.
45. The room next to the power plant is the transformer room. Let's take a look there too.
46. As I already mentioned, the fort was powered through a power cable from outside. In the transformer, the current received from the outside was converted into 110 volts of the fort's internal network. This is what transformers and related electrical equipment look like. All this still works.
47. Behind the transformer room there is a room with huge tanks. They contain water for cooling power plant equipment.
48. It is very difficult to photograph them, since they occupy most of the volume of the room.
49. There are safety instructions on one of the tanks. The one on the left seems to be original from the 30s, and the one on the right looks like a replica or from a later time.
I found an excellent plan on the Internet for the part of the fort we examined. Everything is shown very clearly here. And we go further to the barracks part of the fort.
50. At the end of the technical zone, the postern makes a slight bend, which can be seen in the picture above.
51. The armored doors on the left side of the photograph lead to the barracks part of the fort, and the walls on the right side of the fort lead to two other combat blocks.
52. The scale of the underground labyrinths is very impressive.
53. Bathroom. All the lighting of the fort was duplicated with ordinary candles or gas lamps in case of electricity failure. You can see a candle on the left of the photo. The closed door in the photo is a toilet for officers and command, toilets with half-open doors are for ordinary soldiers.
54. Sewage was collected in special tanks with chemical solvents - prototypes of modern dry closets. The tanks were located under the toilets; there was no classical sewage system in the fort.
55. Next to the toilets there is a small room with washbasins.
56. There are shower rooms nearby. Of the three shower stalls, one was intended for disinfection of victims of toxic gases, the other two were ordinary showers. Every soldier had the right to take a shower once a week.
57. Filter and ventilation unit designed to disinfect victims of a gas attack.
58. Twenty meters from the showers and toilets are the barracks themselves.
59. One of the two rooms with iron beds for ten places was intended for professional workers of the fort: mechanics, orderlies, cooks, electrical engineers.
60.
61. Ordinary soldiers slept in hammocks, which were hung in two levels. This room could accommodate 26 hammocks. The peculiarity of such a room was that the metal structures were easily dismountable, which made it possible to turn the room into a festive hall in a very short time. In 1939, the soldiers of the fort celebrated Christmas here with songs, fun, and wine.
62. Nearby is another room with hammocks, but smaller.
63. Double room for non-commissioned officers.
64. Fort commander's room, the only single room in the fort.
65. The room where the lieutenants lived.
66. The fort also had a small medical unit, consisting of a dressing room...
67. ...and wards for two patients.
68. At this point, the inspection of the barracks is completed, we move to the next location, located next to the barracks - the command center, from where the fort was controlled.
69. The command center is located around the next bend (pictured on the left).
70. Main hall of the command center. Pay attention to the radiator. The fort was heated by air heaters, which supplied warm air to all rooms of the fort. The installation of central water heating was in the process of installation but the work was interrupted by the outbreak of war. Therefore, in different rooms of the fort you can find heating radiators that have never worked.
71. The command center received information about the situation outside and inside the fort. An analysis of the situation was immediately carried out and from here orders were given to various combat units and communication was carried out with neighboring forts.
72. The main sources of information were the fort’s five armored observation towers, information from which was reported to the command center by telephone. Also, thanks to telephone communications with neighboring forts, the fort command was well informed about the situation tens of kilometers around.
73. Appeal of General de Gaulle to the French nation.
74. Telephone cables between the forts were laid at a depth of three meters in the vicinity of the fort and at a depth of two meters in the fields. In addition to direct telephone communication between the forts, each of the forts was connected into a single telephone network, laid a kilometer from the potential front line. In case the telephone line failed, there was a backup option for communication between the forts using signal flares.
75. Telephone exchange. The officers and telephone operators were located closest to the command center in the fort. Thus, when an alarm was declared, the command center began to function almost immediately. Telephone operators recorded all information received from outside in special documents, which were immediately studied by officers, maps of the area were analyzed and decisions were made on firing, which were then transmitted from here to the fort’s combat casemates. The disadvantage of the Maginot Line forts was that they became blind at nightfall or in heavy fog. After all, the aiming of all guns at that time was exclusively visual.
76. At this point we leave the command center and move to the last underground location of the fort - the warehouse.
77. On the territory of the warehouse, in order to fill the empty warehouse spaces, a small museum has been organized with a good collection of various equipment used in the Maginot Line forts, ranging from weapons to periscopes of observation armored domes and various electrical devices.
78. Machine telegraph, similar to ship telegraph. With the help of these devices, commands were sent from the command center of the fort to the combat units and confirmation of their execution was sent back.
79
80. A twin caponier machine gun mount, which was usually installed in the embrasures of the combat blocks of the fort. If necessary, this machine gun mount was removed to the side and a 47-mm anti-tank gun was installed in its place. More about this in the second part of the story.
81. And this is a installation with a combined weapon, which was located inside an AM-type armored dome, which was discussed above (photo 10, 12, 13). The combined weapon was two weapons in one: a machine gun and a 25-mm anti-tank gun. The AM type armored cap was equipped with a system for removing powder gases and ventilation, and a system for supplying ammunition and water to the cap for cooling the weapon.
82. Despite the fact that the armored dome itself was not rotatable, with the help of supporting brackets the heavy weapon could be quickly reinstalled in one of the two embrasures of the armored dome. All adjustments and settings of the gun were carried out by rotating the handles, which greatly simplified its operation.
83. On the way to the first combat block, there is such an appendix of a forgotten postern (see map at the beginning of the post). During the construction of the fort, a much larger number of combat blocks was planned, but after funding cuts, construction had to be limited to three blocks. By that time, they had already completed the turn to the supposed fourth block, which was soon abandoned. It is still unknown how far the forgotten terna travels. The workers of the museum fort here erected a monument to Andre Maginot, the French Minister of War, who initiated the construction of a line of armed fortifications on the border with Germany.
84. Another small room next to the forgotten rubble. Initially, this room was a vertical shaft through which soil was excavated when digging underground tunnels. When the construction work was completed, the trunk was filled in from above, and thus another additional room was formed in the fort. Without thinking twice, they made another barracks room for soldiers.
Having examined all the underground locations of the fort, we find ourselves through a narrow and long passage into block 1. A visit to the third block was not included in the excursion, since it is completely identical to the first block. Both combat units differ only in the mounted guns inside the rotating turret and the design of the turret. These two combat units constitute the main striking force of the fort.
01. Combat block 1 is connected to the fort's underground system by a spiral staircase. Its height is 30 meters and in the event of the enemy’s capture of the underground part of the fort, there was a possibility of blowing up this staircase.
The whole thing looks something like this: 
02. Having overcome 145 steps, we find ourselves in the casemate of the second block. The first thing that greets us at the entrance is a filter and ventilation unit. Each combat unit is equipped with its own FVU. To avoid the penetration of gases inside during combat operations, excess air pressure was pumped inside the block.
03. To the right of the FVU are the soldiers' sleeping places. Let's go a little deeper...
04. In the right corner you can see the niche of the GFM-type armored cap; in addition to standard equipment, it was also equipped with an observation periscope with eight-fold zoom. In addition to the connection between the armored observation towers and the command post of the fort, there was also a direct connection from the observation towers of all blocks with the large artillery fort Gros Ouvrage Simserhof, located eight kilometers from PO Rohrbach, which during the hostilities very strongly supported the small fort with fire, not giving the Germans the opportunity come closer. On the left side of the photo, under the embrasure, you can see a chute for discharging spent cartridges into the diamond ditch.
05. In the lower left part you can see an electric heating radiator. As I already mentioned in the first part, the heating system of the fort began to be converted to central water heating, but did not have time to complete the process due to the war.
06. The room of the officer in command of the combat unit is also located here.
07. The photo shows one of the two twin machine gun installations of the combat unit. Above it you can see a blue rail, under which a 47-mm anti-tank gun was suspended.
08. If necessary, the coaxial machine gun mount was moved to the side.
09. And an anti-tank gun, suspended under the rail and moving along the rail, advanced into the opened embrasure.
10. After an hour and a half spent underground, it was very nice to breathe in fresh air and see the outside world, albeit through an embrasure. I can imagine what it was like for the soldiers forced to live underground for months.
11. Traces of fighting.
I found an excellent drawing online showing the combat unit of the PO Rohrbach fort in section. The combat block is a two-level casemate with thick concrete walls up to 2.75 meters thick in places facing the enemy and 1.5 meters on the sides, the thickness of the reinforced concrete roof is 2.5 m. As can be seen from the figure, the casemate was equipped with two embrasures with twin machine guns installations, which were supplemented by 47-mm anti-tank guns and the main weapon of the casemate was a rotating turret, which will be discussed in more detail below. In addition, the combat unit had two armored caps of the GFM type supplemented with observation periscopes with the possibility of 8x magnification for monitoring the terrain.
Taken from: http://www.fortiff.be/casso/
This is what the first block looks like from a bird's eye view:
photo taken from here.
12. Well, now let’s move on to examining the main weapon of the fort: a rotating armored turret with a firing installation located in it, consisting of two combined guns.
13. This armored turret is a system for placing weapons designed to fire in all directions and suppress both infantry and armored enemy targets. The armored turret of this model was developed back in 1905 and produced in 1915 to equip French battleships. Twelve of these installations never reached the fleet and were kept in reserve until they migrated to the forts of the Maginot Line, where, after minor modernization and the installation of new weapons in 1934, they continued their service on land.
14. The total weight of the turret with guns is 135 tons, but thanks to the counterweight system, two people lifted the turret a meter without much physical effort, bringing it into a firing position. In the closed position, the tower was invulnerable to enemy weapons. The thickness of the armor on the turret roof is 285 mm, the side walls of the turret are protected by 185 mm armor.
15. To control and maintain all turret systems, a team of 18 people was required: one officer, three non-commissioned officers and 14 soldiers. Four of them were inside the turret, controlling the firing and loading of weapons, the remaining ten soldiers served the guidance, communications, ammunition supply systems, etc.
16. In the center of the frame, a machine telegraph for transmitting commands to the shooters inside the tower, copied from ship analogues. On the left you can see the backup light, in case of electrical failure.
17. Old technology is very picturesque: dozens of gears, levers and other incomprehensible pieces of hardware create a beautiful techno-abstraction, from which it is difficult to tear the camera lens away.
18. Another machine telegraph located on the wall. All communication between the command and the soldiers servicing the tower systems was carried out with such devices because, due to the very high noise level during combat operations, transmitting commands by voice was problematic.
19. The photo shows the place of the commander of the battle tower. The black pipe in the center of the frame is a periscope for external surveillance and aiming. Below it are acoustic pipes to communicate with the shooters in the turret before the shooting begins. On the left in the photo you can see a pipe in which there is an elevator for supplying cartridges with cartridges for the turret machine guns. In the same pipe on the opposite side of the rotating mechanism there is a device for supplying cartridges with ammunition for the anti-tank guns of the turret: in the photo, five such cartridges are visible on the table.
20. Another photo of the commander’s seat and we climb inside the tower through the hatch located on the side opposite the commander’s seat.
21. The inside is quite spacious, especially compared to the cramped armored domes.
22. The turret's guns are two anti-tank guns, model SA-L, manufactured in 1934, 25 mm caliber and two twin MAC 31 machine gun mounts, 7.5 mm caliber and rate of fire 1200 rounds per minute. The firing range of machine guns is 1200 m, cannons - 1800 meters. Thus, the turret's armament consisted of four machine guns and two cannons.
23. There were four people inside the tower during the battle: two shooters and two loaders. Special places under the guns were equipped for shooters. In the photo you can see a machine telegraph for receiving commands from below.
24. Fire control and gun aiming were completely mechanized. Aiming was carried out by rotating the handles, which are visible in the photo below. The machine guns were controlled by the same handles. To control the firing of cannons, pedals are provided in the floor.
25. To cool the guns, water cooling was provided, for which purpose a water tank with a capacity of 20 liters was located in the turret. Cooling was carried out by spraying water onto the hot surfaces of the guns using a "Vermorel" type sprayer.
26. The armored turret was equipped with a ventilation and removal system for powder gases. On the lower tier of the combat unit there was an electric fan that pumped clean air into the tower. In the frame you can also see the elevator shaft for supplying ammunition and electric heating resistors above the lamp.
27. Shooters' places.
28. Let's go down to the lower tier of the armored tower. There was an ammunition depot, a turret lifting mechanism and a ventilation unit (on the left in the photo). In case of power surges, the tower could be ventilated manually.
29. Device for raising/lowering the armored turret. These operations were carried out by two soldiers who turned the handles, thereby driving the gear mechanism, which, thanks to a counterweight, raised the 135-ton turret into a firing position or lowered it into a secure shelter. As part of the excursion, everyone was given the opportunity to twirl handles. The tower lowers so easily that even one person can handle it. In other forts, equipped with more modern towers, this function is performed by an electric motor.
Here is a very clear animation that shows how this mechanism works.
source: Association des Amis de la Ligne Maginot
For an even more visual representation, a cross-section of the entire turret mechanism of the first combat unit.
Bypassed Maginot Line
One of the actions by which the Allies were defeated in the 1940 campaign is often seen as bypassing the line of fortifications on the Franco-German border. They were known as the Maginot Line and closed the southern section of the border. It is believed that the line was built with a fatal mistake - the northern section of the border, through which, in fact, the Germans broke through, was not covered. There was no fatal mistake, of course. The task of the Maginot Line was... to direct the German offensive into France along the route of the Schlieffen Plan of 1914, that is, through the Benelux countries. The “Maginot Line” can be called built under the motto of Clausewitz’s statement: “By positioning ourselves behind strong fortifications, we force the enemy to look for a solution elsewhere.” The need to break through strong fortifications should, according to the idea of the line builders, force the Germans to choose a roundabout route. This would allow the Allies to fairly accurately calculate the enemy’s actions and force him to fight in Belgium.
However, in reality, the Germans broke through the “extension” of the Maginot Line in the Ardennes. On May 17, 1940, two 210 mm guns opened fire on the small fortification of La Fère. On May 18, two casemates with 75-mm cannons were abandoned by their garrisons. German assault groups began to make their way into the depths of the fortifications. The nearby fortification of Le Chêne attempted to support the defenders of La Fère with 75mm gun fire, but the casemates were too far away for the fire to be any effective. By the end of the day on May 19, the entire La Fère fortification was captured, and the road into the interior of France was open to the Germans. Between 20 and 23 May, four Maubeuge fortifications were destroyed one by one. The final blow to the Maginot Line came in June 1940 during Operations Tiger and Bear. 420 mm artillery, dive bomber strikes, and assault groups were used against the fortifications. In general, we can say that the Maginot Line was, although with difficulty, broken through by the Germans in several places. No less dramatic events unfolded in Belgium. Many people are well aware of the capture of Fort Eben-Emael by paratroopers. Indeed, on May 10, 1940, paratroopers in 40 gliders landed on the roof of Fort Eben-Emael and forced the garrison to capitulate by detonating shaped charges on the domes and turrets of the fort. However, this action distracted public attention from much more important events. From May 10 to May 15, 1940, there was a battle between assault groups of infantrymen and the garrison of Fort Aubin-Neufchateau. With the help of 305 mm and 355 mm, Fort Battis was destroyed, capitulating on May 22. The Verdun experience was not in vain. Forts in World War II were no longer an insurmountable obstacle for the army, which had gained experience in positional warfare on the Western Front in 1914–1918.
This text is an introductory fragment.The Second World War, which began 70 years ago, was further proof that generals were preparing for the wars of the past. The memory of the positional meat grinders of the last war forced the governments of different countries to begin constructing large-scale, colossally equipped defensive lines.
Despite the expenditure of enormous financial resources, not one of these “new Chinese walls”, for one reason or another, fulfilled the role assigned to it. The most famous to a wide audience are the three defensive lines built before the war: Maginot Line, Mannerheim Line and Stalin Line. Let's begin our acquaintance with them with the most perfect, but this did not make it any more useful, French Maginot Line of fortifications.
French defense plan
The French generals believed that the Germans would act in the same way as in the 1914 campaign. They will try to make a breakthrough from the northeast through the territory of Belgium. The French defense plan included repelling the German offensive on the Dyle River, with passive defense on the fortifications of the Maginot Line. Construction of this line began in 1928 and by 1936 the main construction work was completed. Responsible for the construction of the “insurmountable line” of defense was the French Minister of War Andre Maginot, after whom the system of fortifications was named.
The 10 richest provinces were located in the eastern part of France, in which in the 30-40s of the last century about 60% of steel and steel products were produced, 76.5% of zinc and 94% of copper were mined. Whatever the course of the war, the army had to do everything possible to prevent the Germans from entering these important economic areas. Primarily from the northern and northeastern directions.
In military science, there are 2 main types of defense - rigid (positional) and maneuverable.. In positional defense, troops stubbornly defend the chosen line and try to prevent the enemy from crossing the front line. At the same time, maneuverable defense is based on the fact that positions are not held rigidly and can be surrendered; when the enemy exhausts his reserves and offensive capabilities, the defenders try to regain the lost position with counterattacks. Maneuverable defense fully allows for the temporary loss of individual territories.
The maneuverable type of defense is especially loved by the military, and in most cases is not tolerated by statesmen and politicians. The military loves it because this method does not make the defending troops passive, does not allow the attacking enemy to impose its will, and allows it to seize the initiative at the right moment and go on the offensive. While positional defense puts the defenders in a deliberately losing position, because the enemy will sooner or later find a gap in the defense, which will be fraught with the encirclement of the entire defending group.
Maneuverable defense makes politicians nervous; it can be very difficult for them to explain to the population of the country the loss of this or that territory, its abandonment under the rule of the occupiers and the associated human and material losses. The country's population often views this as a bad move in the war. Morale, as well as trust in politicians, is falling, which can be fraught with defeat.
The task of the French army in the war was to prevent the Germans from entering the richest industrial areas of France, which would put the country in a difficult situation and deprive the army of the opportunity to replenish resources. Paris saw a way out of the situation in building an impenetrable defense along the German border, which required the construction of powerful fortifications capable of withstanding the fire of large-caliber artillery and holding back attacks from large masses of infantry for a long time.
The French were well aware that the Wehrmacht would try to break into France through Belgium, as in the First World War, and the Maginot Line simply would not allow them to strike elsewhere. In Paris, it was believed that by holding most of the northern and north-eastern border, they would not allow the Germans to enter the industrial areas of the country, forcing the Germans to field battles in northern France with the transfer of fighting to Belgium. At the same time, the French generals believed that at any moment they would be able to launch a counterattack on the enemy from behind the Maginot Line in the direction of the north, cutting off the entire German army and intercepting all its supply lines.
Maginot Line
The French spent a very impressive amount for those times on the construction of the Maginot Line - about 3 billion francs or 1 billion dollars. The total number of troops stationed on the line reached 300,000 people. The underground multi-level forts housed premises for personnel, powerful ventilation units, power plants, narrow-gauge roads, rest rooms, hospitals, telephone exchanges, which were inaccessible to bombs and shells. In the upper ground floors there were gun and machine gun casemates, equipped with elevators for supplying ammunition.
The forts were concrete “boxes” dug deep into the ground, the thickness of whose walls reached 3-4 meters. At the top there were usually only armored turrets. In front of the first line of defense, whenever possible, anti-tank ditches were dug and barriers made of anti-tank hedgehogs were erected. Behind the first line of defense there was a whole network of strong points - concrete platforms designed to accommodate infantry, artillery, and searchlights.
Ammunition and equipment warehouses were located at a depth of up to 50 meters. In the depths of the defense there were long-range artillery positions on the railway. Even further away was the old modernized defensive line, which included the forts of Belfort, Verdun, Epinal and several others. The depth of the Maginot Line in some areas reached 90-100 km, the French generals considered it impregnable.
The floor structure of the forts looked something like this. On the surface there were only concrete machine-gun nests and artillery blockhouses, anti-tank pits and barriers. Below, a number of floors of the fort went underground, the connection between which was carried out by stairs and elevators, the maximum depth of the fortifications could reach 100 meters. The thickness of the reinforced concrete roof of any fort reached 3.5 m, which made it possible to withstand shelling from shells of up to 420 mm caliber.
On the first two floors of the fort there were premises for the garrison. A number of diesel engines were also installed here, driving ventilation units that supplied air to all rooms of the fort, as well as dynamos that ensured the generation of electricity. Similar engines were located on other floors, acting as backup engines in case any of them failed.
On the third floor of the fort ammunition for current ammunition supply and supplies of water and food were placed. On the fourth floor there was a telephone exchange and the fort's office premises.
On the fifth floor there were supplies of medicines and hospital premises, below at the sixth level there was a tunnel of an electrified underground narrow-gauge railway, through which the rapid transfer of ammunition and troops to the desired direction was carried out. The main track of this underground metro was double-track, auxiliary access roads were single-track.
At the seventh floor level was the fort headquarters, even lower were located reserve ammunition depots and reserve diesel engines. To a sufficiently great depth, the fort was protected by solid concrete walls, which eliminated the possibility of penetration into the fort or its undermining using a tunnel.
The Maginot Line was a miracle of fortification thought of its time:
– 5600 long-term defensive fortifications,
— 70 bunkers,
— 500 artillery and infantry units,
- about 500 casemates,
- numerous dugouts and observation posts.
The length of the line is about 400 km. The average density was 7.7 structures per 1 km of front(in some areas this number reached 14). Nowhere between the bunkers were there gaps exceeding 8 km in length. Some of the pillboxes were equipped with artillery and machine-gun armored caps, which could be raised to fire and then lowered underground, avoiding enemy return fire.
The basis of the fortified sectors were large forts, between which there were small forts and individual bunkers, as well as tank towers. All combat installations of the US were united by a single command, and their location on the ground ensured mutual visibility and communication. The fire system was organized in such a way that neighboring structures could always support an attacked fort or bunker with fire, or close the gap with fire if the fortification was captured or destroyed by the enemy.
Some of the fortified areas were equipped with special dams, which ensured the flooding of vast territories and underground structures in the event of their capture by the enemy. During the construction of the line, many advanced military engineering solutions were used at that time.
Frustration
Many historians believe that the Maginot Line did not fully justify itself, which is only partly true. The line fulfilled its main purpose - it greatly limited the scale of attacks on those areas that were protected by it. The tragedy was different - numerous miscalculations of the French command and the country's leadership negated all the advantages that this most powerful defensive line in the world provided them.
The main and most tragic mistake of the French generals was that they were unable to predict the new tactics that the Wehrmacht imposed on them. The Germans made their trump card the swift attacks of large mechanized formations, the main striking force of which were tanks.
The field defense of the French army and the English expeditionary force simply could not withstand the onslaught of mechanized formations. Contrary to the plans of the French command, they failed to impose positional battles on the Germans either in Belgium or in northern France, allowing German units to reach the rear of the Maginot Line.
/Based on materials popmech.ru, rusproject.org And azbukivedi-istoria.ru /
The Maginot Line is a system of French fortifications on the northeastern border from Dunkirk to the island of Corsica that was built in 1929-1935. Then it was improved until 1940, which led to the inclusion in the line of not only heavy fortifications (400 km long), but also light ones, with a total length of about 750 km. The line is named after the Minister of War Andre Maginot. It included: 118 large and small forts, about 750 casemates, about 100 shelters and armed barracks, almost 15 thousand checkpoints (blockhouses) and observation posts. The line, according to the latest version of the French command, was intended to contain the enemy’s advance while mobilization was carried out, and then as a strategic springboard for a counteroffensive.
At least 7.4 billion francs, or 5 billion dollars in 2010 prices, were spent on the construction of the fortifications. The total number of troops on the line reached 300 thousand people. The underground multi-level forts were equipped with living quarters for personnel, power plants, powerful ventilation units, narrow-gauge railways, telephone exchanges, hospitals, rest rooms, inaccessible to shells and aerial bombs. In the upper ground floors there were gun casemates equipped with elevators. They were concrete “boxes” dug into the ground with walls and ceilings 3.5-4 meters thick. An armored turret protruded upward. In front of the first line of defense, anti-tank ditches were dug and barriers made of anti-tank hedgehogs were erected. Behind the first line of defense there was a network of strong points - concrete platforms for infantry, artillery, searchlights, etc. At these points, at a depth of about 30 meters underground, there were warehouses for ammunition and equipment, equipped with elevators. Even further away were positions of long-range, large-caliber guns on railway tracks. The old defensive line, consisting of forts Belfort, Epinal, Verdun and others, was also modernized. The depth of defense of the Maginot Line was 10-15 km.
French military strategists considered the Maginot Line impregnable. Therefore, it was assumed that the Germans would act in the same way as in 1914 - they would bypass the French troops through Belgium from the northeast. Therefore, their defense plan involved repelling a German attack on the Dyle River and passive defense on the fortified Maginot Line. Actually, the Germans did just that, bypassing the Line through Belgium at the beginning of the offensive. Having led their armored divisions through the forested areas of the Ardennes, the German motorized divisions were a surprise to the Allies in Belgium.
French fortifications along the border with Belgium were weak, some of them were still at the construction stage, and some did not have stationary weapons. In addition, they were built in swampy areas, where the construction of underground structures was very difficult. However, according to the Diehl plan, the Allies did not intend to allow the Germans to these fortifications. It was planned that in the event of an attack on Belgium, the Allies would advance to the Belgian defensive lines and defeat the enemy there. In reality, the Belgians did not have time to properly prepare their defensive lines, and the Allies did not have time to occupy them and organize a reliable defense. As a result, German troops passed through Belgium “like a knife through butter” without noticing resistance from either the Belgians themselves or the Allies.
On June 14, 1940, the day of the fall of Paris, the German 1st Army launched Operation Tiger and attacked the Maginot Line between St. Avold and Saarbrücken in its central sector. The next day, the German 7th Army attacked in the Southern Sector and penetrated deep into the defenses, capturing the cities of Colmar and Strasbourg. The “impregnable” defensive structures of the Maginot Line, although in the weakest places, were broken through in a few hours as a result of the infantry offensive, even without tank support. The German infantry advanced with powerful air and artillery support, and smoke shells were widely used. It soon became clear that many of the French bunkers could not withstand direct hits from artillery shells and aerial bombs. In addition, a large number of structures were not suitable for all-round defense, and they could easily be attacked from the rear and flank with grenades and flamethrowers. On June 17, Wehrmacht units that entered France through Belgium reached the rear of the Maginot Line, and although unsuccessfully attacked several fortified areas. The line was cut off from the rest of France. Almost all of the Line's structures remained intact and combat-ready when the French command ordered to abandon the fortifications and surrender. Some strongholds continued to fight despite calls for surrender. The last bunker capitulated only on July 10th. Of the 39 main fortified areas on the Maginot Line, only 10 were captured by the Wehrmacht in battle. About 500 thousand French troops were captured.
Along with the legend about the inaccessibility of the Maginot Line, the second legend about the most powerful French army in Europe also died. After the war, part of the Maginot Line structures was transferred to warehouses for military equipment. Since that time, a flying sarcastic expression appeared in the world - the “Maginot Line” - when they wanted to note the huge amount of money for a meaningless cause. This term also refers to a feeling of false security.
The Second World War, which began 70 years ago, was further proof that generals were preparing for the wars of the past. The memory of the positional meat grinders of the last war forced the governments of different countries to begin constructing large-scale, colossally equipped defensive lines. Despite the expenditure of enormous financial resources, not one of these “new Chinese walls”, for one reason or another, fulfilled the role assigned to it. The most famous to a wide audience are the three defensive lines built before the war: the Maginot Line, the Mannerheim Line and the Stalin Line. Let's begin our acquaintance with them with the most perfect, but this did not make it any more useful, French Maginot Line of fortifications.
French defense plan
The French generals believed that the Germans would act in the same way as in the 1914 campaign. They will try to make a breakthrough from the northeast through the territory of Belgium. The French defense plan included repelling the German offensive on the Dyle River, with passive defense on the fortifications of the Maginot Line. Construction of this line began in 1928 and by 1936 the main construction work was completed. Responsible for the construction of the “insurmountable line” of defense was the French Minister of War Andre Maginot, after whom the system of fortifications was named.
The 10 richest provinces were located in the eastern part of France, in which in the 30-40s of the last century about 60% of steel and steel products were produced, 76.5% of zinc and 94% of copper were mined. Whatever the course of the war, the army had to do everything possible to prevent the Germans from entering these important economic areas. Primarily from the northern and northeastern directions.
In military science, there are 2 main types of defense - rigid (positional) and maneuverable. In positional defense, troops stubbornly defend the chosen line and try to prevent the enemy from crossing the front line. At the same time, maneuverable defense is based on the fact that positions are not held rigidly and can be surrendered; when the enemy exhausts his reserves and offensive capabilities, the defenders try to regain the lost position with counterattacks. Maneuverable defense fully allows for the temporary loss of individual territories.
This type of defense is especially loved by the military, and in most cases is not tolerated by statesmen and politicians. The military loves it because this method does not make the defending troops passive, does not allow the attacking enemy to impose its will, and allows it to seize the initiative at the right moment and go on the offensive. While positional defense puts the defenders in a deliberately losing position, because the enemy will sooner or later find a gap in the defense, which will be fraught with the encirclement of the entire defending group.
Maneuverable defense makes politicians nervous; it can be very difficult for them to explain to the population of the country the loss of this or that territory, its abandonment under the rule of the occupiers and the associated human and material losses. The country's population often views this as a bad move in the war. Morale, as well as trust in politicians, is falling, which can be fraught with defeat.
Sector firing point hidden from flanking fire
The task of the French army in the war was to prevent the Germans from entering the richest industrial areas of France, which would put the country in a difficult situation and deprive the army of the opportunity to replenish resources. Paris saw a way out of the situation in building an impenetrable defense along the German border, which required the construction of powerful fortifications capable of withstanding the fire of large-caliber artillery and holding back attacks from large masses of infantry for a long time.
The French understood perfectly well that the Wehrmacht would try to break into France through Belgium, as in the First World War, and the Maginot Line simply would not allow them to strike elsewhere. In Paris, it was believed that by holding most of the northern and north-eastern border, they would not allow the Germans to enter the industrial areas of the country, forcing the Germans to field battles in northern France with the transfer of fighting to Belgium. At the same time, the French generals believed that at any moment they would be able to launch a counterattack on the enemy from behind the Maginot Line in the direction of the north, cutting off the entire German army and intercepting all its supply lines.
Maginot Line
The French spent a very impressive amount for those times on the construction of the Maginot Line - about 3 billion francs or 1 billion dollars. The total number of troops stationed on the line reached 300,000 people. The underground multi-level forts housed premises for personnel, powerful ventilation units, power plants, narrow-gauge roads, rest rooms, hospitals, telephone exchanges, which were inaccessible to bombs and shells. In the upper ground floors there were gun and machine gun casemates, equipped with elevators for supplying ammunition.
The forts were concrete “boxes” dug deep into the ground, the thickness of whose walls reached 3-4 meters. At the top there were usually only armored turrets. In front of the first line of defense, whenever possible, anti-tank ditches were dug and barriers made of anti-tank hedgehogs were erected. Behind the first line of defense there was a whole network of strong points - concrete platforms designed to accommodate infantry, artillery, and searchlights. Ammunition and equipment warehouses were located at a depth of up to 50 meters. In the depths of the defense there were long-range artillery positions on the railway. Even further away was the old modernized defensive line, which included the forts of Belfort, Verdun, Epinal and several others. The depth of the Maginot Line in some areas reached 90-100 km; French generals considered it impregnable.
Fortifications of the Maginot Line, today
The floor structure of the forts looked something like this. On the surface there were only concrete machine-gun nests and artillery blockhouses, anti-tank pits and barriers. Below, a number of floors of the fort went underground, the connection between which was carried out by stairs and elevators; the maximum depth of the fortifications could reach 100 meters. The first two floors of the fort contained quarters for the garrison. A number of diesel engines were also installed here, driving ventilation units that supplied air to all rooms of the fort, as well as dynamos that ensured the generation of electricity. Similar engines were located on other floors, acting as backup engines in case any of them failed.
The third floor of the fort housed ammunition for current ammunition supply and supplies of water and food. On the fourth floor there was a telephone exchange and the fort's office premises.
On the fifth floor there were supplies of medicines and hospital premises; below on the sixth level there was a tunnel of an electrified underground narrow-gauge railway, through which ammunition and troops were quickly transferred to the desired direction. The main track of this underground metro was double-track, auxiliary access roads were single-track.
Narrow gauge railway connecting bunkers and fortified areas of the Maginot Line
At the level of the seventh floor there was the fort headquarters, and even lower there were reserve ammunition depots and reserve diesel engines. To a sufficiently great depth, the fort was protected by solid concrete walls, which eliminated the possibility of penetration into the fort or its undermining using a tunnel.
The Maginot Line was a miracle of fortification thought of its time - 5,600 long-term defensive fortifications, 70 bunkers, 500 artillery and infantry blocks, about 500 casemates, dugouts and observation posts. The length of the line is about 400 km. The average density was 7.7 structures per 1 km. front (in some areas this number reached 14), nowhere between the bunkers were there gaps exceeding 8 km in length. Some of the pillboxes were equipped with artillery and machine-gun armored caps, which could be raised to fire and then lowered underground, avoiding enemy return fire. Some of the fortified areas were equipped with special dams, which ensured the flooding of vast territories and underground structures in the event of their capture by the enemy. During the construction of the line, many advanced military engineering solutions were used at that time.
Frustration
Many historians believe that the Maginot Line did not fully justify itself, which is only partly true. The line fulfilled its main purpose - it greatly limited the scale of attacks on those areas that were protected by it. The tragedy was different; numerous miscalculations of the French command and the country's leadership negated all the advantages that this most powerful defensive line in the world provided them.
The main and most tragic mistake of the French generals was that they were unable to predict the new tactics that the Wehrmacht imposed on them. The Germans made their trump card the swift attacks of large mechanized formations, the main striking force of which were tanks. The field defense of the French army and the English expeditionary force simply could not withstand the onslaught of mechanized formations. Contrary to the plans of the French command, they failed to impose positional battles on the Germans either in Belgium or in northern France, allowing German units to reach the rear of the Maginot Line.
Fortifications of the Maginot Line, today
Sources used:
www.popmech.ru/article/5840-liniya-mazhino/
www.rusproject.org/pages/history/history_10/secret_maginot.php
www.azbukivedi-istoria.ru/publ/politika/podzemnye_forty_linii_mazhino/2-1-0-105
materials from the free Internet encyclopedia "Wikipedia"
