Heavy 30.5cm Kartaune L/30 (30.5cm barrel L/30 on mortar chassis)

The Heavy 30.5cm Kartaune L/30/ 30.5cm Beta-M-Gerät howitzer was produced in an attempt to get more use out of the M-Gerät carriage by fitting a longer barrelled but smaller calibre barrel.

The idea was to increase the range of the M-Gerät, which had been very effective in the sieges of 1914, but had become increasingly obsolete as the nature of the fighting changed, and Allied guns with longer range entered service, making them vulnerable to counter-battery fire.

Work on the Beta-M-Gerät began late in 1917. A 30.5cm L/30 naval barrel was installed on the M-Gerät carriage and recoil system. Both of these components needed some changes, and the modifications took one-two months. The new barrel was twice the length of the old one, and weighed 16 metric tons. Two large equilibrators had to be added at the front of the carriage to counterbalance the extra weight (appearing as vertical cylinders carried on either side of the barrel, in front of the shield).

Twelve barrels were produced for the project, and early trials suggested that the project had been worth-while, as the modified weapons had a range of 20,500m.

By early in 1918 two batteries, KMK 8 and KMK 10 each had two of the modified Beta-M-Gerät howitzers. However soon after they entered combat the new guns proved to have a fatal weakness - the barrels were prone to burst when used with the full propellant charge, as the high pressures generated in the barrel triggered premature detonations. As a result their range was limited to 16,500m, an improvement on the original M-Gerät, but not as much as expected, and still placing it within range of Allied counter-battery fire.

During the spring offensives of 1918 KMK 8 was allocated to the Sixth Army in Flanders, but it had little impact. KMK 10 took part in the last German offensive of the war, in July 1918, fighting with the First Army at Reims, but again with little impact. In the autumn of 1918 KMK 10 swapped to standard long range field howitzers, leaving only KMK 8 equipped with the Beta-M-Gerät.


30.5cm Beta-M-Gerät howitzer
Heavy 30.5cm Kartaune L/30



Barrel Length

9,150mm (L/30)

Weight for transport

47,000kg with bed plate

Weight in action



0 to 65 degrees


10 degrees

Shell Weight


Muzzle Velocity

600 m/sec

Maximum Range


Rate of Fire

One round every five minutes

German Artillery 1914-1918, Wolfgang Fleischer. Covers over 100 guns used by the German Army and shore detachments of the Navy during the First World War, a conflict largely dominated by artillery. Each one gets a brief description, a set of technical stats and a good picture. Shows the wide range of gun types and sizes used by the Germans during the First World War, and the way in which they evolved to deal with the unexpected challenges of trench warfare. [read full review]
cover cover cover

Books on the First World War | Subject Index: First World War

How to cite this article: Rickard, J (5 December 2017), Heavy 30.5cm Kartaune L/30 (30.5cm barrel L/30 on mortar chassis) , http://www.historyofwar.org/articles/weapons_30_5cm_kartaune_L30.html

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