AC47 B1 de La-Ferté (SF Montmédy)

General information

Artillery of Maginot fortification
Its armament is of gauge equal to or higher than 75mm.
In 1940 the mortar of 81mm (with artillery) is often been useful by infantry.

Infantry of Maginot fortification
Its armament is of gauge lower than 75mm.

Anti-tank devices

The works are equipped with many anti-tank weapons:
75mm been useful by artillery
AC 47mm, 37mm, 25mm been useful by the infantry

The casemates of bank of the Rhine and the Low-Vosges are equipped with the machine-gun Hotchkiss anti-tank devices of 13,2mm.

Others weapons

Other materials (105, 130,155…) are studied, a certain time. The 145 long range (30km) is even retained after 1934, but its high cost remains dissuasive. Flame throwers are evoked, even tested, then garaged in the paperboards, on standby.

Here we will not evoke that the weapons installation and usable in 1940.

Rifle machine gunner of 7,5mm type 1924 modified in 1929

This FM, of fortification, has neither the bipod, neither the crutch, nor the handle hand-shield of the normal FM 24/29 which equips out of standard the troops with the French Army until 1965; these three accessories are indeed useless in the fortifications (and even incompatible with the attachment units on the crenels).

In front of the triggers, the removal of the handle hand-shield lets appear a protuberance used to fix normal FM on a mounting of vehicle, for example. In the fortification this protuberance is made profitable to maintain FM on its support. Below, FM is on a device SP (On Porte) with the shelter of Bichel-South (SF Thionville).

Above, FM 24/29 is in its crenel, on its most current kneecap RB (SFAM Bridge-St-Louis)

Above, FM 24/29 is in its crenel, on its reinforced kneecap (standard B) (Rohrbach SF Rohrbach)

FM 24/29 (official name: MAC 24/29) is an automatic light machine-gun built by the munitions factory of Chatellerault. Approved in 1924, the series is launched in 1925, and the Units touch it since 1926. In 1929 it is modified to draw the cartridges 7,5mm 1929 more powerful than the cartridges 7,5mm from 1924 initial.

MAC created an alternative “special fortification” of the 24/29: the 24/29D of which the gun reinforced car the ammunition of 7,5D (heavy ammunition with greater range than the 7,5 normal for infantry). If the 24/29D become the typical weapons of defense close to the Maginot Line (of bell, of crenels under concrete, door), employed in twinnings they are very quickly replaced by famous twinnings of machine-guns MAC 31.

Characteristics
- Charger of 25 cartridges, on the top of FM, which requires a side offset of the apparatus of aiming
- Rate of shooting: 450 blows/min
- Range: 3000m with the ordinary ball, 5100m with the perforating ball D
- Practical Range: 600m
- Canon of 500mm with 4 stripes on the left with the step of 235 mm
- Initial Speed: 850m/s
- Effect: bore 3mm steel with 400m with the perforating ball
-2 triggers, for the shooting step by step and another for the shooting in gust
- Mass charged, for the FM of fortification (thus without accessories, bipod…) : 9,830kg
- More precise characteristics are given on specialized sites.

Head of chute (also called chute) places from there in the staff waiting room of the work of Cape-Martin (SFAM).

Grenade chute

It is a system made up:
- of a tube with 45° which crosses the cement wall armed with the blocks of works
- of a head of chute in the casemate.

One opens the head of chute and one introduced there a defensive grenade. The blocked grenade, one takes the pin out it and one closes. The grenade waits until the push of a spring propels it in the tube where it rolls. During its displacement the grenade arms and bursts approximately 4 seconds after its exit of the tube.

Chute with Wood-of-furnace (SF Crusnes).

Howitzer of 75/29 (SFAM. Castillon Block 3)

75mm model 1929 of casemate

Characteristics:
- Canon primarily studied for the casemates of flanking and the fight anti-tank devices
- Canon of casemate with real pivot and retreat court of 45cm
- Its flight exceeds 1,5m outside the crenel
- Amplitude of pointing in height: - 9° with +40°30'
- Amplitude of pointing in direction: 45°
- Maximum Range: 12000m
- Maximum Rate of shooting: 30 blows/min
- Ammunition: Standard cartouche of countryside
it is equipped with a sight tube allowing the direct shooting.

Howitzer of 75/29. Museum of Fermont

Crenels of 75/29. Barbonnet B2. It is noted that the flight of the gun exceeds crenel and is thus vulnerable.

Howitzer of 75/32 (SF Crusnes. Fermont Block 3)

75mm model 1932 of casemate

Characteristics:
- As the gun model 1929 he is primarily studied for the casemates of flanking and the fight anti-tank devices
- Its fictitious pivot makes it possible to obtain a flight exceeding only 0,45m outside the crenel (contrary to the material of 1929)
- Amplitude of pointing in height: - 9° with +40°30'
- Amplitude of pointing in direction: 45°
- Maximum Range: 12000m
- Maximum Rate of shooting: 30 blows/min
- Ammunition: Standard cartouche of countryside
it is equipped with a sight tube allowing the direct shooting.

Crenel of one 75/32. Fermont B4. It is noticed that it exceeds crenel very little and is thus less vulnerable than the 75/29. It is of as much less vulnerable than when it does not draw the side steel shutters are closed and protect it.

Turret for two 75/33 (Fermont SF Crusnes). The turret is with eclipse and here it is out of battery. It is noted that the two guns do not exceed a turret, which protects them from the unfavourable blows. Between the two guns one can see the end of the sight tube.

75mm model 1933

75/33 of turret

Howitzer of 75/33 in the turret of Agaisen B3 (SFAM).

Characteristics:
- Material designed for the turrets with eclipses
stolen it of the two guns does not exceed outside the turret
- Amplitude of pointing in height: - 2° with +40°
- Amplitude of pointing in direction: 360°
- Maximum Range: 12000m
- Maximum Rate of shooting: 30 blows/min
- Ammunition: Standard cartouche of countryside
it turret is equipped with a sight tube installed in the room of shooting and which allows the direct shooting, in particular for the fight anti-tank devices.

75/33 of casemate

Material designed for the armoured casemates of frontal action of the Alps (in Rimplas SFAM). We did not find any photograph of this type of gun, rare.

Characteristics:
- Canon of casemate with fictitious pivot
- Its flight does not exceed outside the crenel
- Amplitude of pointing in height: - 9° with +40°30'
- Amplitude of pointing in direction: 45°
- Maximum Range: 12000m
- Maximum Rate of shooting: 30 blows/min
- Ammunition: Standard cartouche of countryside
it is equipped with a sight tube allowing the direct shooting, in particular for the fight anti-tank devices.

AC47 out of battery with La-Ferté B1 (SF Montmédy).

AC 47mm model 1934

It is an anti-tank gun, with tended shootings, installed in the crenels of twinnings of machine-guns.

The AC47 is suspended with a carriage what makes it possible to withdraw it crenel and to replace it by a JM.

The AC47 is out of battery (on the left). The JM of which it took the place is erased, on its line (one distinguishes its support who swivelled). At the bottom one sees another JM out of battery.

Characteristics:
- Rate of shooting: 18 blows/min
- 800m its shell has bores 8cm steel

AC37 exposed to the museum of Hackenberg (SF Boulay).

AC 37mm model 1934

It is an anti-tank gun, with tended shootings, installed in the crenels of twinnings of machine-guns when the casemate is too reduced to be able to accomodate a AC47.

Characteristics:
- Rate of shooting: 18 blows/min
- 800m its shell has bores 5cm steel. It is thus less powerful than the AC47.

Turret of Schoenenbourg B3 (SF Haguenau).

75R model 1932

This material equips only certain works with the North-East. It is employed when the ground, too broken, cannot be effectively beaten by the howitzers.

75R 32 of turret

Characteristics:
stolen it of the two guns does not exceed outside the turret.
- Amplitude of pointing in height: - 5° with +35°
- Amplitude of pointing in direction: 360°
- Maximum Range: 9200m
- Ammunition: Cartouche 1915 with divisible load.
it turret is equipped with a sight tube installed in the room of pointing and which allows the direct shooting, in particular for the fight anti-tank devices.

Interior of a turret for two 75R 32 (Furnace-with-Lime SF the Vosges).

75R 32 of casemate

Material little employed. We did not find photographs of them.

Characteristics:
- Its flight does not exceed outside the crenel
- Amplitude of pointing in height: - 17° with +34°
- Amplitude of pointing in direction: 45°
- Maximum Range: 9200m
- Ammunition: Cartouche 1915 with divisible load.
it is equipped with a sight tube allowing the direct shooting, in particular for the fight anti-tank devices.

75.05 of turret

Only 2 of these guns, going back to before 1914, were used on the Line Maginot (restrictions of appropriations in 1934). They armed the turret with eclipse with Chesnois (SF Montmédy). We do not have of it a photograph.

Characteristics:
- Its flight does not exceed outside the crenel
- Amplitude of pointing in height: - 5° with +30°
- Amplitude of pointing in direction: 360°
- Maximum Range: 8200m
- Ammunition: Cartouche 1915 with divisible load.
it is equipped with a sight tube allowing the direct shooting, in particular for the fight anti-tank devices.

Machine-gun of 13,2mm model 1930

Arms built by Hotchkiss for the fight anti-tank devices. This material equips only the casemates with bank of the Rhine and the Low-Vosges.

Characteristics:
- It is a machine with shootings tended installed in the crenels of twinnings of machine-guns.
- Suspended on a carriage it can be erased and be replaced by a JM.
- Ammunition: ball model 1935
- Rate of shooting: 450 blows/min
- Charger of 30 cartridges

Mortar of B2 Holy-Agnes (SFAM). It equips only the works with the Alps. It makes it possible to beat the bottom of the valleys and the contrepentes by curved shootings.

75mm model 1931 of casemate

Characteristics:
- Material designed for the casemates of flanking.
- Its flight does not exceed outside the crenel.
- Amplitude of pointing in height: -3° with +35°
- Amplitude of pointing in direction: 45°
- Maximum Range: 5900m
- Ammunition: Encartouché semi standard projectile with short casing.
- Well that it is a mortar it can carry out tended shootings. For this purpose it is equipped with a sight tube.

Turret for two mortars of 81mm of Fermont B5 (SF of Crusnes). The turret, in eclipsed position, is slightly with the lower part of the level of the flagstone of the block.

81mm model 1932

Arms exclusively with curved shooting.

81mm of turret

Characteristics:
stolen it of the two mortars does not exceed outside the turret.
- Amplitude of pointing in height: null. Its shooting is with constant angle. The range is regulated by a vent with variable opening.
- Amplitude of pointing in direction: 360°
- Maximum Range: 3600m
- Ammunition: Bend with auxiliary loads.
it material, not being able to carry out tended shootings, is not equipped with a sight tube.

81mm of casemate

Mortar of the Holy-Agnes B2 (SFAM)

Castillon B3 (SFAM).

Crenel of 81. Wood-of-furnace (SF Crusnes).

Characteristics:
- Its flight does not exceed outside the crenel.
- Amplitude of pointing in height: null. Its shooting is with constant angle.
it range is regulated by a vent with variable opening.
- Amplitude of pointing in direction: 45°
- Maximum Range: 3600m
- Ammunition: Bend with auxiliary loads.
- Interest of an amplitude of pointing in null height and that the embrasure can be of very reduced size. This decreases the possibilities of enemy impacts and, especially, increases the resistance of the walls of the blocks.
it material, not being able to carry out tended shootings, is not equipped with a sight tube.

Trumelage for bells AM (Museum of Fermont). Anti-tank gun of 25mm associated with two machine-guns MAC 31 F in a fixed bell.

25mm model 1934 (mixed Weapons)

Anti-tank gun which, considering its compactness, can be associated with two machine-guns on the same kneecap. The unit is then anti-tank and anti-personnel without change of material, contrary to what occurs with the JMAC47. However the gun of 25 is much less powerful than that of 47.

Characteristics of the 25mm:
- Length Tubes: 1m with 1,8m according to the model
- Maximum Range 1.800 m
- Projectile of 0,32kg at initial speed 918 m/s
- Borer a shielding of 40 mm to 400 m
Give rhythm shooting: 18 blows/min

25mm under concrete, bells and turrets

The gun of 25 being of compactness, and less expensive than that of 47, it is prescribed, since 1934, for any types of crenels.

Trumelage for turret mixed weapons TAM (Museum of Fermont). Anti-tank gun of 25mm and two MAC machine-guns 31 F

Opposite: turret of 135 (on the right) eclipsed. Furnace-with-lime B1 (SF the Vosges).

135mm model 1932. Launch bombs

135mm of turret

Characteristics:
- It is a machine with curved shootings specialized in the dismantling of work of enemy approach
stolen it of the two bomb throwers does not exceed outside the turret
- Amplitude of pointing in height: 9° with +45°
- Amplitude of pointing in direction: 360°
- Maximum Range: 6000m
- Ammunition: Semi-encartouché projectile with short casing.
- Maximum Rate of shooting: 8 blows/min
- The weapon, not being able to carry out tended shootings, the turret is not equipped with a sight tube.

135mm of casemate

135mm of B2 of Holy-Agnes (SFAM)

Characteristics:
- It is a machine with curved shootings specialized in the dismantling of enemy work of approach
- Material designed for the casemates of flanking
- Its flight does not exceed outside the crenel
- Amplitude of pointing in height: 0° with +40°30'
- Amplitude of pointing in direction: 45°
- Maximum Range: 5700m
- Ammunition: Semi-encartouché projectile with short casing.
- Maximum Rate of shooting: 8 blows/min
- This machine, not being able to carry out tended shootings, is not equipped with a sight tube.

Crenel for bomb thrower of 135mm in Hackenberg B9 (SF Boulay).

Opposite: mortar on a bell GFM of Hackenberg (SF Boulay).

Mortar of 50mm model 1935

It is a machine with curved shootings primarily installed in bells GFM of the type A.

Mortar with its support for bell GFM, exposed to the museum of Hackenberg (SF Boulay)

Characteristics:
- Like the mortar of 81mm it takes care by the cylinder head and draws with constant angle from 45°
- A mechanism of vent makes it possible to regulate the range of the projectile between 65m and 1400m
- Rate of shooting: 10 to 30 blows/min
- Projectile: Bend with wings of 950g.

Twinning of machine-guns for crenel under concrete.

Machine-gun of 7,5mm model 1931

Two machine-guns MAC 31 F are twinned (Reibel twinning, of the name of the General which develops it in 1930) what makes it possible to draw with one while the other cools and that a provider the refill.

Characteristics of MAC 31 F:
- Canon of 0,6m from length to four grooves on the left with the step of 235.
- Maximum Range: 5000m
- Ammunition: cartridge gauges 7,5mm (like FM 24/29) out of chargers Camembert cheese of 150 cartridges
- Cadance of shooting: 750 blows per minute.

The MAC31F is installed in many types of crenels

Twinnings of machine-guns are indeed under concrete, bell JM, turret (of machine-guns or mixed weapons).

Twinning under concrete in Rohrbach (SF Rohrbach).

75/32 Fermont (SF Crusnes)

Differences between Field artillery and Artillery of Fortress

Document of Mr. Walter whom we thank warmly.

The difference between Field artillery and Artillerie of Fortress is primarily technical, and rises from their respective uses: first is mobile, the second operates in fixed telephone; It follows of the important transformations for comparable gauges (Many gauges were created for the fortresses, little are only adaptations of current gauges of field artillery). I will describe you here the major differences specific to artillery of fortress:

• Frames: The trains of bearings are replaced by structures fixed on the ground, with the partitions, when they purely and are not simply omitted. (Direct Fixings with armourings of embrasures, on working shutters, certain retractable bells).
• The bodies of pointings limit their clearances, “are practically atrophied”, adapting to the configurations of the zones to beat and those of the casemate which shelters the part (There exists an architectural regulation which associates the armaments and the structure of the shelter).
• The optical bodies of aimings are non-existent, except for the anti-tank parts with vocation, or of defense of proximity.
• The elastic Bonds (bodies which absorb the push of the departure of the blow and bring back the tube “out of battery”) have innovating techniques, permitted by the work-holding; They act more quickly, of or an increase in the rates of fire.
• The provisions of food and evacuation of waste (casings) tend to be rationalized, there is in spite of very much work to the hand.
• Pieces of ordnance (the tube):
  - Short cuts, they are less vulnerable, but lose in precision. The artillerist adjusts his shooting with coordinates precisely charted, observers on the site or under bells, connected at the height by telephone or radio, the results and the modifications of coordinates give.
  - The tubes, with gauge equivalents, are much thicker. (it is what is noticed initially). They are manufactured to support rates without deformations. (heating). Moreover, the ranges are lengthened because one can then improve chemistry of the propelling loads (casings).