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.
