The 21 cm Mörser 16 (21 cm Mrs 16) or langer 21 cm Mörser was a heavy howitzer used by Germany in World War I and World War II.
It was based on the earlier 21 cm Mörser 10, but had a longer barrel, a gun shield and other refinements. Originally it broke down into two loads for transport, but the Germans rebuilt surviving guns during the Thirties with rubber-rimmed steel wheels to allow for motor traction in one piece with a limber under the trail and generally removed the gunshield.
In German service it used two shells, the 21 cm Gr 18 (HE) that weighed 113 kilograms (250 lb) and the 21 cm Gr 18 Be concrete-piercing shell of 121.4 kilograms (268 lb) with a filler of 11.61 kilograms (25.6 lb) of TNT.
They remained in first-line use with the Germans until replaced by the 21 cm Mörser 18 by about 1940. Afterwards they were used for training and equipped units in secondary theaters.
Weight: 6,680 kilograms (14,700 lb)
Barrel length: 2.675 metres (105.3 in) L/14.5
Shell: separate-loading, cased charge
Caliber: 211 millimetres (8.3 in)
Breech: horizontal sliding wedge
Carriage: box trail
Elevation: -6° to +70°
Rate of fire: 1-2 rpm
Muzzle velocity: 393 metres per second (1,290 ft/s)
Maximum range: 11,100 metres (12,100 yd)