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25cm schwerer Minenwerfer

1910 WORLD WAR 1

History of the 25cm Heavy Mortar

During the fighting in the First World War (1914-1918), the German Imperial Army recruited several "ditch mortars". These include the 7.58cm and 17cm mine throwers (literally "mine throwers"), but none are larger than the heavy trench mortar 25cm heavy mine thrower.

Developed between 1907 and 1909, the system was finally introduced in 1910. Production continued into 1918, with the initial wartime output increasing from just 44 to an impressive 1,234 by the end of the war.

Like other world military powers, the Germans watched with interest the development of the Russo-Japanese War (1904-1905) and took these observations to heart as they developed their own modern doctrine. The war was the first real conflict of the 20th century.

The siege of Port Arthur (30 July 1904 to 2 January 1905) proved the value of large-caliber siege guns, which led to the development of similar systems in Germany.

The muzzle-loading design features a 25 cm (250 mm) caliber with a rifled barrel for long-range accuracy. The recoil is assisted by a hydraulic spring system. A two-wheeled "box track" wagon was used to make the gun work. The actual launcher got off when it was ready to fire.

Its metal construction means the system weighs about 1,700 pounds and requires several crew members to operate and move (as well as road transport heavy loads). The transmitter has an elevation range of +45 to +75 degrees, with a traverse limit of 12 degrees on each side. Standard HE (High Explosive) rounds weigh 110 pounds, while heavier rounds weigh 210 pounds and can also be used on more "hardened" targets.

Each projectile is charged separately by four discs. The muzzle velocity is as low as 660 feet per second, the effective range is 585 yards, and the maximum range is 1,000 yards. Sightings were made through a panoramic viewing arrangement.

Eventually, two barrel lengths were developed - the original "a/A" L/3 model was 2' 6" and the n/A 4 L/5 model was 4'.

In practice, the bulky 25cm unit proved very effective due to its ability to carry heavy shells. It has a fairly short range but allows for useful indirect fire without a line of sight, meaning firefighters are relatively protected when deployed in sunken locations such as trenches.

Early success in this area has led to a focus on making more of these products, increasing general availability. These weapons proved to be much cheaper and more expensive to maintain than their larger German counterparts such as railguns and heavy artillery.

In 1916, the introduction of the new 25cm trench mortar led to the use of the above-mentioned longer L/5 barrel (n/A = "Neuer Art" or "Neues Modell"). A longer rifled barrel increases the overall effective range, resulting in a more powerful weapon.

This resulted in the L3 barrel form being identified as the "a/A" designation of "Alter Art" ("old model").

The 25cm heavy mine thrower was in use until the end of the war in November 1918. Since then, most guns in Germany have been reduced in capacity and many forms have been scrapped or given as trophies/reparations.