Historic context :
Germany pre-war invasion plans induced the quick conquest of numerous fortified towns both in the West aend in the East. The necessity of a powerful and mobile heavy siege artillery therefore had been recognized early, and transformed into several calibres weapons, including the famous 21cm, efficient against bricks and concrete fortifications.
The 21cm M 1899 mortar did not have a recoil recuperating system, at the detriment of its fire precision and rate. Answering to the APK request, Krupp started in 1902 the design of a modernisation. It took not less than 3 prototypes ('21cm VersuchMorser') and 7 years of design to issue the new 21 cm morser, presented in 1909. But the result was worth the long delay, since the '21cm Morser M10', also kown as 'der Mörser' instantaneously became a major weapon of the German artillery, and accumulated brilliant victories from the the very first weeks of the war.
This new weapon overclassed the old 1899 mortar on all the dimensions, with a modern hydro-mechanic recoil recuperation system improving the fire rate and the precision, an elongated barrel (from 10 to 12 calibres) allowing an almost 2000 m range increase, and a very good manoeuvrability on the battlefield.
The 21cm M 10 was delivered to the army units from 1910, and 216 such guns were available to the German corps at the war outbreak. The first victories soon came, it is rocognized that the fall of Liège, Namur and Maubeuge forts in 1914 is mainly due to these mortars fire, while the use of the terrifying higher calibres only destroyed some of these targets, but received much more propaganda advertisement.
This gun heavy weight needed its decomposition into three 'cars' for transportation : the carriage transportation car ('Lafette mit Protze'), the barrel transport car ('Rohrwagen'), and the accessories transport car ('Gürtelwagen') including the wheels belts.
A total of 474 such mortars were produced by Krupp before this company switched its production to the 1916 version. 219 of them were still fighting in November 1918.
216 such mortars equipped the German Armies at the conflict outbreak, and were named '21 cm Morser M10', or 'der Mörser'. That mortar needed 3 'cars' for its transportation in separate loads : the carriage, the tube transportation car, and the accessories car.
Technical data :
- Complete description : 21cm mortar M 10
- Design year : 1910
- Calibre : 211.00 mm
- Weight in firing position : 6630 kg (7380 kg with trackpads)
- Weight for transportation : 3 wagons 3720 kg (with tube), 3713 kg (with carriage) and 3345 kg (with accessories)
- Tube length in calibres : 12.00 (total tube length)
- Grooves : 64
- Projectile weight : 120 kg
- Initial speed : 367 m/s
- Fire rate :
- Range : 9400 m
- Elevation range : +6 / +70 degrees
- Direction range : 4 degrees total range