The 8.4 cm Feldgeschütz Ord 1879 is a 19th century Swiss field gun. It replaced the 8.4 cm Feldgeschütz Ord 1871. The difference was that the Ord 1879 had a barrel of steel instead of bronze. The steel barrel was made by Krupp in Essen, Germany. The carriage was made by the Eidgenössische Konstruktionswerkstätte in Thun.
The gun was the last field gun without recoil mechanism in the Swiss army. In turn it was replaced by the Krupp 7.5 cm Model 1903. The gun continued to be employed in fortresses till the end of World War II.
Evolution, History
Preceding 8.4 cm Feldkanone Ord 1871 and Dutch 8 cm A. Bronze
After the Franco-Prussian War the Swiss developed a number of breechloading guns. Amongst these was the 8.4 cm Feldkanone Ord 1871, a rifled breechloader field gun with a bronze barrel. In total 358 pieces were ordered in 1871. Also in 1871, the Dutch army bought one of these guns, and started to produce it locally in 1874. In the Netherlands the 8.4 cm Feldgeschütz Ord 1871 would become known as the 8 cm A. Bronze.
The 8.4 cm Feldgeschütz Ord 1879
In the 1870s there was a strong debate about whether bronze was still suitable for gun barrels. Already in 1874 two massive steel barrels of 84 mm caliber were procured from Krupp for testing purposes. These massive steel barrels showed that with equal weight, the steel guns could take heavier charges and wore down more slowly. The next step was the procurement of a built-up gun barrel () from Krupp in 1878, again for testing. The Artillery committee and Ministry of Defense reported favorably about this barrel.
On 24 April 1878 the Federal Council then decided to modernize the field artillery by adopting the Krupp barrel. It was mounted on the carriages of the 8.4 cm Feldkanone Ord 1871 without any modification. In 1879 the first 15 8.4 cm Feldkanone Ord 1879's were delivered. The old bronze barrels Ord 1871 were handed over to the Festungsartillerie, or recast. Steel guns had already been introduced in the Swiss army in 1877 when the Krupp breechloader 7,5-cm-Gebirgskanone Ord 1877 replaced the Gebirgskanone Ord 1864.
The Dutch 8 cm staal
The Dutch government had the same doubts as the Swiss about bronze guns. By 1879 the Dutch government had decided that their 8 cm bronze guns would be replaced by either steel or a steel bronze guns. Meanwhile three steel bronze guns were constructed in the second half of 1879. In 1880 the Dutch trial with steel bronze guns for the army failed unexpectedly. In 1880 the defense minister then decided to buy a 84 mm gun from Krupp. It would become known as 8 cm staal. It had the same 84 mm caliber as the 8.4 cm Feldgeschütz Ord 1879, but it was a bit longer and had another breech. The 8 staal also had a steel carriage.
The 8.4 cm Positionskanonen 1887 L 25
When Franz von Uchatius invented steel bronze, many countries reverted to using bronze for guns. Bronze was cheaper, and easier to manufacture, meaning that these countries were no longer dependent on foreign countries for manufacturing guns. In 1882 two steel bronze barrels were ordered at Sulzer. Tests of these barrels were positive, and so in January 1887 it was decided to procure 56 of these for the newly organized (light siege batteries). The steel bronze version was placed on a fortification carriage that also fit the other 8.4 cm guns. The breech of this 8.4 cm Positionskanonen 1887 L 25 equaled that of the 8.4 cm Feldkanone Ord 1871. Due to a somewhat higher elevation it had somewhat more range. In order to absorb recoil it rolled back and upward on rails, and was returned to its position by gravity.
Gradual replacement
After the introduction of the 7,5-cm-Feldkanone 1903 L 30 the first 8.4 cm Feldkanone Ord 1879 (1881/93) were handed over to the fortress troops. In August 1940 97 were handed to this part of the armed forces. At the end of World War II, 18 were still in service.
Characteristics
Barrel
The 8.4 cm Feldgeschütz Ord 1879 (later: Ord 1881/93) weighed 1,100 kg ready to fire. The Krupp barrel was a built-up gun. The inner tube had a breech, and was coiled with two other layers. In total, the barrel and breech weighed 425 kg. The outer length of the barrel was 25.6 caliber, or 2150 mm. On the inside the length till the breech was 1930 mm. The barrel had 24 grooves, increasing from 0 to 4 degrees. The breech was closed with a Broadwell Ring. This ring was pressed forward on closure, and then pressed back by the explosion, preventing the escape of poisonous gasses.