21 cm Mörser 18

Infobox Weapon
name=21 cm Mörser 18


caption=fancifully-painted Mrs 18 at the US Army Field Artillery Museum, Ft. Sill, OK
origin=Germany
type=heavy howitzer
is_ranged=
is_bladed=
is_explosive=
is_artillery=yes
is_vehicle=
is_UK=
service=1939-1945
used_by=flag|Nazi Germany
wars=World War II
designer=
design_date=
manufacturer=Krupp
production_date=1939-1942
number=
variants=
weight=16,700 kg (36,817 lbs)
length=6.51 m (21.35 ft)
part_length=6.07 m / 29 calibers
width=
height=
crew=
cartridge=separate-loading cased ammunition (6 charges)
caliber=211 mm (8.30 in)
action=
rate=
velocity=550 m/s (1,804 ft/s)
range= 16,725 m (18,290 yds)
max_range=
feed=
sights=
breech=horizontal sliding block
recoil=dual-recoil hydropneumatic
carriage=box trail
elevation=-6° to +70°
traverse=16° on wheels
360° on platform
blade_type=
hilt_type=
sheath_type=
head_type=
haft_type=
diameter=
filling=
filling_weight=
detonation=
yield=
armour=
primary_armament=
secondary_armament=
engine=
engine_power=
pw_ratio=
suspension=
vehicle_range=
speed=

The 21 cm Mörser 18 (heavy howitzer) (21 cm Mrs 18) was a German 211 mm (8.31") heavy howitzer used in the Second World War by independent artillery battalions and batteries. A number were also used by coast defense artillery units.

Design & History

The Mrs 18 was designed to replace the obsolescent WW I-era 21 cm Mrs 16. While the gun design itself was nothing innovative, the same cannot be said for the carriage. It was one of the first weapons, if not the first in quantity production, that used the interesting dual-recoil system. The barrel recoiled normally in its cradle, but, in addition, the whole top carriage, which carried the barrel and its cradle, recoiled across the main part of the carriage. This system damped out the recoil forces and made for a very steady firing platform. This carriage was also used for the 17 cm Kanone 18 in Mörserlafette and the 15 cm Schiffskanone C/28 in Mörserlafette.

The Mrs 18 was an enormous weapon that was transported in two pieces, as was common for such large weapons. For travel the barrel was slid on to a separate trailer. The carriage carried an integral firing platform that was lowered to the ground when emplacing the howitzer. The wheels were then cranked up off the ground and it was now ready for firing. A rear castor-wheel jack was used to raise the rear spade off the ground if the gun needed to be traversed more than allowed by the 16° allowed by the mount proper.

The Mrs 18 entered production at a low rate in shortly before the war began. The Germans cancelled production in 1942 in lieu of its smaller brother, the 17 cm Kanone 18 in Mörserlafette, which could fire almost twice as far.

References

*Englemann, Joachim and Scheibert, Horst. "Deutsche Artillerie 1934–1945: Eine Dokumentation in Text, Skizzen und Bildern: Ausrüstung, Gliederung, Ausbildung, Führung, Einsatz". Limburg/Lahn, Germany: C. A. Starke, 1974
*Hogg, Ian V. "German Artillery of World War Two". 2nd corrected edition. Mechanicsville, PA: Stackpole Books, 1997 ISBN 1-85367-480-X