7.5 cm mountain cannon 1933 L 22
| 7.5 cm mountain cannon 1933 L 22 | |
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| General Information | |
| Manufacturer country: | Sweden , Switzerland |
| Developer / Manufacturer: | Bofors , / Sulzer brothers , K + W, Thun |
| Development year: | from 1929 |
| Start of production: | 1936 |
| Weapon Category: | Mountain gun |
| Technical specifications | |
| Caliber : |
75 mm |
| Cadence : | 15-20 rounds / min |
| Elevation range: | 50 degrees |
| Furnishing | |
| Ammunition supply: | Breech loader |
The Swiss 7.5 cm mountain cannon 1933 L 22 replaced the 7.5 cm mountain cannon Ord 1906 manufactured by Krupp . The weapon was later converted to the 7.5 cm Mot Geb Kan 1938 L 22 and after the Second World War to the 7.5 cm Mot Geb Kan 1948 L 22 to enable the motor train.
Evaluation, commitment
On December 8, 1924, the Federal Council decided to renew the mountain artillery. Major General Bridel, chief artillery proposed to replace the 7.5-cm-mountain guns Ord in 1906, as they were heavily imposed in some cases. As a replacement, he suggested the Škoda M 1914 mountain gun manufactured by the Škoda company in Pilsen, with various barrel variants in 9-10.5 cm calibers. The EMD compared this weapon with a 7.5 cm caliber gun developed by the Swedish company Bofors . The reason was that this was more modern and fired lighter ammunition, which was an advantage because of the difficult transport conditions in the mountains. Both guns had a maximum elevation of 50 ° and could therefore also be used as howitzers. After attempts, the Federal Council decided in 1933 in favor of the Bofors gun; Another advantage was that it could be manufactured under license in Switzerland. This cannon, which was further developed into the 7.5 cm Mot Geb Kan 1938 L 22 , was first sold to the Mot during World War II. Can. Batteries handed over to the Light Brigades. A disadvantage of the weapon was its small side pivoting range and the low projectile speed when used for anti-tank purposes. From 1941 onwards, the weapon was increasingly given to the mountain troops.
During the war, Sulzer also produced longer pipes, L 30 instead of L 22, for installation in fortresses. Two such fortress guns are located in the fortress Reuenthal . They are mounted on a minimal card carriage.
The gun
The 7.5 cm mountain cannon 1933 L 22 weighs 790 kg ready to fire, 850 kg ready to go. The gun barrel and breech block manufactured by Sulzer are one-piece and made of solid steel. When firing, the system runs back 800 mm on the upper carriage, which is equipped with a reverse brake , is hydraulically braked and brought forward again by 2 springs. The horizontally inserted flat wedge lock works semi-automatically. This means that it closes automatically by spring force after the cartridge has been inserted; the gun is ready to fire. When the system moves forward after the shot, the breech opens automatically and ejects the fired case. The weapon is ready to be loaded. The shot is fired by the built-in shutter lock , the firing pin strikes the centrally mounted in the sleeve bottom primer. Total length of the tube 1650 mm, caliber 7.5 cm. Constant right-hand twist 25 cal, 7 ° 10 '. Total length of the gun 1.8 m, width (axis length) 1 m, track 0.76 m.
The weapon was always used from its single- arm mount , which was prevented from rolling back by ramming the ground spur attached to the rear end . It was divided in its front area, this opening allowed the return of the pipe when shooting at a steep angle. In contrast to a spreading carriage, it only allowed a small adjustment of the lateral direction from 53 per thousand to the left and to the right. The altitude range was minus 175 per thousand plus 875 per thousand (50 °), so the gun could also be used like a howitzer in indirect shot.
The operating team consisted of a gun chief and 5, later 8 men. When deployed, the gunner sat on the left and the loader on the right on seats attached to both sides of the mount. The aiming and aiming device was attached to the side of the reverse brake directly in front of the gunner. It consisted of the drum attachment with the telescopic sight and aiming telescope attached to it. The drum attachment was used to regulate the pipe inclination. A closable opening was attached to the protective shield for direct aiming. If the aiming device failed, an auxiliary aiming device for indirect aiming could be attached directly to the rear of the tube.
The transport of the 7.5 cm mountain cannon in 1933, pulled on its wheel carriage with iron-tyred wooden wheels, was carried out by horse-drawn train or in 9 loads. In contrast to its predecessor, the 1938 model was equipped with metal wheels with hollow-chamber rubber tires; in 1948 these were replaced by wheels with tires. Both guns weigh a little heavier.
Ammunition used
The projectiles used in the 7.5 cm mountain cannon 1933 L 22 and its successors corresponded to those in the 7.5 cm field cannon, the 7.5 cm cannon 03/22 L 30, introduced into the artillery from 1903 . Shrapnel were no longer fired in the mountain cannon. The casings used were slightly shorter than those of the field cannon, as the unit charge (Ladg 5) of the mountain cannon was smaller. The bullet and the case were loaded into the barrel as a unit. One was shot
- Steel grenade with double fuse (St G DZ), weight 6.4 kg
- Steel grenade with instant igniter (St G MZ), weight 5.75 kg
- Smoke grenade with instant igniter (RG MZ) weight 5.75 kg
- Pointed grenade with instant igniter (Sp G MZ), weight 5.95 kg
- Rauch pointed grenade with instant igniter (R Sp G MZ), weight 5.95 kg
- Tank shell
ballistics
When using the largest possible charge (Ladg. No. 5), the following initial speed v 0 and shooting distance were achieved:
- St G DZ, 465 m / s, 8700 m
- St G MZ, RG MZ, 484 m / s, 8900 m
- Sp G MZ, R Sp G MZ, 480 m / s, 10,000 m
literature
- Les Bouches à Feu de l'Artillerie Suisse, Author: Lt. Col. Jean de Montet, 1980, Edition du Center d'Histoire, Lausanne.
- Artillery II, recoil guns, author: Walter Betschmann, 1984, Verlag Stocker-Schmid, Dietikon-Zürich, ISBN 3-7276-7059-2
- Report of the Chief of the General Staff to the Commander-in-Chief of the Army on active service 1939–1945