| 21 cm Mörser 10 | |
| Origin: | German Empire |
| Type: | Howitzer |
| Is Artillery: | yes |
| Service: | 1910 |
| Used By: | German Empire |
| Wars: | World War I |
| Designer: | Krupp |
| Design Date: | 1907–1910 |
| Production Date: | 1910 |
| Weight: | 15496lb |
| Part Length: | 2.57m (08.43feet) L/12 |
| Cartridge: | 252lb |
| Caliber: | 211mm |
| Velocity: | 335 m/s (1,101 ft/s) |
| Max Range: | 9400m (30,800feet) |
| Breech: | horizontal sliding-wedge |
| Recoil: | hydro-pneumatic |
| Carriage: | box trail |
| Elevation: | -6° to +70° |
| Traverse: | 4° |
The 21 cm Mörser 10 (21 cm Mrs 10) was a heavy howitzer used by Germany in World War I (although classified as a mortar (Mörser) by the German military). It replaced the obsolete 21 cm Mörser 99, which lacked a recoil system. For transport, it broke down into two loads. Some howitzers were fitted with a gun shield during the war. As it was also intended for siege use, a concrete-penetrating shell was also used. Unusually, it had two spades: a folding one halfway down the trail and a fixed one at the end of the trail. Before the 21 cm Mörser 10 was commissioned for mass production, a small test series of 21 cm Versuchmörser 06 ("test mortar") was given to the German army. Eight pieces equipped two batteries, but their range of only 7 km was found insufficient, so the range was increased for the production version. Serial number 3 of these rare pieces is now exposed at Red Cliffs, Victoria.[1] 216 were in service at the beginning of the war.[2] It was replaced by the 21 cm Mörser 16, which was also known as the langer 21 cm Mörser since it was merely a lighter 21 cm Mrs 10 with a longer barrel for extra range and other refinements. The specifications provided for this weapon by difference sources are contradictory and, thus, those given here cannot be regarded as authoritative.