7.5 cm mountain cannon Ord 1877
| 7.5 cm mountain cannon Ord 1877 | |
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| General Information | |
| Manufacturer country: | Germany |
| Developer / Manufacturer: | Krupp food |
| Start of production: | 1875 |
| Number of pieces: | 24 |
| Weapon Category: | Mountain gun |
| Technical specifications | |
| Overall length: | 1.8 m |
| Caliber : |
75 mm |
| Elevation range: | -10 ° - + 26 ° angular degrees |
| Side straightening area: | firmly |
| Furnishing | |
| Ammunition supply: | Breech loader |
The 7.5 cm mountain cannon Ord 1877 replaced the outdated muzzle-loading mountain cannon Ord 1864 . The breech- loader manufactured by the Krupp-Gussstahlfabrik in Essen was the last mountain cannon used in the Swiss Army without a return barrel. It was replaced by the 7.5 cm Ord 1906 mountain cannon, also manufactured by Krupp .
The gun
The 7.5 cm Ord 1877 mountain cannon weighs 256 kg in use. Gun barrel and breech block are one-piece and made of solid steel. The horizontally inserted flat wedge lock is lined with a Broadwell ring . The tube and cap together weigh 105 kg. The firing of the shot is triggered by a friction tube inserted into the tube by the shooter standing next to the wheel igniting it by tearing the line. Total length of the tube 963 cm, bore 11.3 caliber resp. 84.5 cm. The drawn part measures 69.4 cm, has 24 draws, draw depth 1.25 mm, progressive twist. The barrel is placed with its support pin on a steel riveted wall mount, total length of the gun 1.8 m, width (axis length) 1 m, track 0.76 m.
The weapon was always used from the wheel mount. Since the tube was placed on the carriage with a trunnion , the lateral direction had to be corrected by shifting the carriage tail sideways. To adjust the elevation , a screw is attached to the mount at the rear end of the barrel. The elevation range is minus 175 plus 460 artillery per mille. In order to reduce the return of the gun, the wheels could be blocked with restraint ropes.
The gun, pulled on its wheel carriage, was transported by horse, for this purpose a forked drawbar could be attached to the end of the carriage. In difficult terrain, the gun could be dismantled and basted by four horses, three for the gun and one for the ammunition. The individual loads carried by the horses were between 160 and 122 kg.
ballistics
When 400 g of black powder were used, the initial speed of an explosive projectile weighing 4.3 kg was 315 m / s. When using 170 g of paper powder Ord. 1893, it was 310 m / s.
The values of the firing board distance / firing angle / final speed V / e for the ring grenade when using 170 g of rolling paper powder were:
- 1000 m, 3 ° 16 ', V / e 263 m / s
- 2000 m, 7 ° 28 ', V / e 230 m / s
- 3000 m, 13 ° 17 ', V / e 203 m / s
- 4000 m, 22 ° 30 ', V / e 181 m / s,
Ammunition used
The ammunition was loaded separately, after the grenade had been introduced, the propellant charge was loaded in a cloth sack and the breech closed. Then the friction tube was used, the weapon was ready to fire.
The Ord 1877 mountain cannon fired the Ord 1877 ring grenade, weight 4.3 kg, explosive charge 100 g black powder, impact fuse, with 10 iron rings inserted to increase the fragmentation effect.
The Shrapnel Ord 1882 weighed 4.6 kg. Filling 110 hard lead balls of 15 g each, propellant charge filled in at the bottom of the projectile: 55 g black powder no. 2, double igniter with temperature division, burning time 10 s.
literature
- Les Bouches à Feu de l'Artillerie Suisse, Author: Lt. Col. Jean de Montet, 1980, Edition du Center d'Histoire, Lausanne.
- Artillery I, artillery guns without mechanical barrel return. Author: Walter Betschmann, Stocker-Schmid Verlag, Dietikon-Zürich, ISBN 3-7276-7009-6
- Artillery III, The way to a uniform artillery system, author: Walter Betschmann, 1984, Verlag Stocker-Schmid, Dietikon-Zürich, ISBN 3-7276-7059-2
- Ordinance over the ammunition of the 7.5 cm mountain guns. Approved by the Swiss Federal Council on July 26, 1878