30.5cm schwerer Küstenmörser 09/ Beta-Gerät 09

The 30.5cm 30.5cm schwerer Küstenmörser 09/ Beta-Gerät 09 was the second in a series of very heavy German guns designed to deal with strong French and Belgian fortifications, and was developed alongside the more famous 42cm gamma-gerät.

The first attempt to produce a mortar capable of dealing with the strong fortifications along Germany's western frontier was the 30.5cm schwere Küstenmörse L/8, or Beta-Gerät of the 1890s. This was a very heavy weapon that needed twelve hours to emplace, and there were already concerns about its penetrative power when it was completed, but work on a successor didn't begin until 1907, after the new Chief of the General Staff, Helmuth von Moltke the Younger, ordered a study into the performance of the Beta-Gerät. As a result of this study two new projects got underway - a 30.5cm mortar and a 42cm gun (the Gamma-Gerät).

The new Beta-Gerät 09 was a very different weapon to the early Beta-Great. That had been a fairly simple weapon, with a gravity recoil system, on a heavy but ground based carriage. The new mortar had a much longer barrel - 4,880mm compared to 2,440mm, a screw-type breech, a two-cylinder pneumatic recoil system attached to the barrel, all mounted on a large carriage, itself positioned on top of a box base plate, designed to absorb more of the recoil forces. The barrel was thus several meters above ground, so two crew platforms were attached to the carriage and there was a sloping munitions lift to bring the heavy shells up to the breech level (often used with a small railway to bring the shells to the base of the lift). The new weapon was one-third heavier than the Beta-Gerät, and needed 37 railcars to move an entire two gun battery. Each gun took five railcars to move. Once it reached the railhead, twelve narrow gauge rail cars were needed to move one howitzer.

The Beta-Gerät 09 had a range of 11,900m, well up on the 8,200m of the Beta-Gerät, and the greater muzzle velocity meant that it had much more destructive power. The first example underwent trials in 1908, and did so well that a second one was ordered in 1909. However in the spring of 1910 any further production was cancelled in favour of the heavier 42cm guns. 

Just before the outbreak of war in 1914 the two Beta-Gerät 09s joined beta­battery No.5, operating alongside the earlier Beta-Gerät, which equipped batteries 1 to 4. This battery was equipped with road wagons towed by steam powered tractors.

The battery took part in the siege of Mauberge, where the bombardment began at the end of August.

Battery SMK 5 then took its Beta-Gerät 09s to Antwerp. The battery opened fire on 28 September, hitting Fort Waelhem. The battery then opened fire on Fort Breendonk, which held out for three days.

After the end of the siege of Antwerp the impact of the heavy guns began to fade. The battery moved to the Channel front, where it was used to bombard Nieuport, Dixmude and Ypres, although without much impact. They remained in use for the rest of the war, but their impact was rarely noted by the Allies, probably because it was hard to distinguish their impact during the massive artillery bombardments of the later war years.


30.5cm schwerer Küstenmörser 09
Beta-Gerät 09



Barrel Length

4,880mm (L/16)

Weight for transport


Weight in action



43-67 degrees


40 degrees

Shell Weight


Muzzle Velocity

394m/sec AP
418m/sec HE

Maximum Range


Rate of Fire

1 round every two 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]
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Books on the First World War | Subject Index: First World War

How to cite this article: Rickard, J (20 November 2017), 30.5cm schwerer Küstenmörser 09/ Beta-Gerät 09 , http://www.historyofwar.org/articles/weapons_30_5cm_schwerer_morser_09.html

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