In the early stages of WW1 the Austro-Hungarian 30.5cm M.11 Mörser was probably the most feared weapon fielded by any Army, and it was used with telling effect both on the Western Front as well in the East, both in the Balkans as well against Italy. The design of the M.11 Mörser started in 1905, when the Austro-Hungarian General Staff ordered the construction of a mortar heavy enough to penetrate and eliminate the new Italian fortifications erected on the border between the two countries. The order proper went to Skoda in Pilsen, who already had made a name for themselves, producing many excellent artillery pieces. (Pilsen is now a part of the Czech Republic: many of the men who designed and built the gun were also Czechs, including of course the man behind the Skoda Works, Dr Karel Skoda.)
The design work was finished in July 1908, and the first prototype of the new gun was built the following year. It was tested intensively in the summer of 1911, showing an impressive performance but revealing some problems, problems that however were not large enough to prevent the Austro-Hungarian from accepting the new Skoda gun under the official designation of "30.5cm Mörser M.11". The first order came in December 1911, calling for the construction of 24 M.11s.
It was a very state-of-the-art piece of artillery, considering the year: 1911. The breech was of the horizontal wedge type, with several safety devices against accidental discharge. Above the barrel were two cylinders: they housed the recoil brake. Below the barrel were three other cylinders: they housed the recuperator, i.e. the mechanism responsible for forcing the gun barrel back into position after the recoil following the discharge of the gun. The barrel and cradle was attached to a bottom carriage, which contained the elevating and traversing mechanisms (the elevation depended on two prominent toothed arcs, visible from the front). The carriage was in it’s turn attached to a bottom box, made by steel, providing the necessary stability for such a big piece of hardware. (In a pinch, it could be fired without the base box, but this was not recommended, as it restricted the traverse heavily.) The gun used a standard dial sight.
The gun itself was of course very heavy: 20,830 kg In order to move the M.11, it had to be dismantled, which was a surprisingly efficient and fast operation, using only jacks and hoists. This dismantling resulted in three big parts: barrel, gun carriage and base box, all who were put upon special wheeled carriages. (The base box could in turn be folded around itself, making it small enough for easy transport.)
Then these three wheeled assemblies were attached to the big Skoda-Daimler M.12 15-ton Tractor. The whole train of vehicles was not fast, but surprisingly mobile. If there was a roadway of reasonable quality present, the gun could be moved there: employment in the Alps were thus no problem.
For all long hauls, the gun was of course transported by train, but all tactical movement was performed by the aid of this tractor. In 1916, a modified version of the M.11 appeared: the M.16, being somewhat heavier, and having a somewhat longer range.
The Austro-Hungarian Army marched to war with 24 M.11s, using them at first not against the intended targets, the Italian border forts, but against Russian and Serbian targets. Also, the German Army, much impressed by this heavy gun, were able to borrow 8 M.11s in 1914, and they used them with terrible effect against their enemies, especially the modern Belgian border fortresses around Liège, that were condidered to be among the strongest in the world. (The Germans had their own Mörser, the M-Gerät of 42cm Calibre, the so called Dicke Bertha, but at this time only two of these monsters were available. The M-Gerät was also heavier and bigger and thus much less mobile than the Austro-Hungarian gun.) In the East, the M.11s were instrumental in breaching several key Russian strongholds, especially the modernized belts of forts around Lemberg-Lvov and Przemysl.
It soon became clear, that modern forts could withstand any amount of shelling from ordinary Field Artillery up to a calibre of 210mm: this was to be proved at Verdun, where forts like Douamount or Vaux were not silenced or even suppressed, even though they had been, literally, hit tens and thousand of times by these lighter calibre grenades: in the end, they had to be taken by storm. In contrast, almost nothing could withstand a direct hit from a M.11 (or a M-Gerät). A grenade from a M.11 could slice through two meters of concrete, bursting in the a fort’s interior and killing and maiming people en masse. (Also, an unforseen consequence of these penetrations, were that the gas and smoke from the detonation filled casemattes and corridors, forcing the crew away, sometimes even to the surface.) Putting it simply: there was no real protection against the M.11, unless you were some 3 meters down in solid rock or maybe reinforced concrete. A bursting grenade from a M.11 produced a crater of some 5-8 meters in diameter: splinters from the burst could penetrate solid structures within 100 meters and kill unprotected persons within 400 meters. Just the tip of the grenade of the M.11 could create as much damage as would a complete 15cm grenade! Putting it crudely: this was a horrific weapon.
During 1915, additional M.11s were issued to the Army, and at the end of that year, the Austro-Hungarian Army fielded 20 M.11 batteries. Although the standard complement of a M.11 battery was 2 guns, the 30.5cm Mörser was a special weapon, that could be used singly. (Especially in situations of static warfare, the Austro-Hungarian Army often combined guns of different calibres and capabilities into special groups, employed in a pretty static role. This is connected to another characteristic of the Austro-Hungarian Army: they, in contrast to the Germans, were not in favour of highly centralized artillery commands. Instead they tended to dole out even very heavy guns, to the control of the division commanders, giving each Division more direct support of their own, but at the same time decreasing the amount of fire power that could be massed at a single point. This is, of course, a reflection of the German Army being more geared towards the attack, while the Austro-Hungarians slowly losing their self-confidence, and becoming more and more oriented towards defence. (This is also the explanation of another Austro-Hungarian peculiarity, that the Germans tended to critize: the fact the the Austro-Hungarians in general deployed their batteries further back than the Germans, who could push even very heavy guns like the 21cm Mörser almost up to the firing line.)
Below you can find some photos of a large-scale contemporary industrial model of a 30.5cm - and can be therefore be thought to be very accurate -, that can be seen in the Army Museum in Prague. The quality of the photos are poor, but they are interesting, both in that they show details otherwise hard to see, and also the colouring: I think that this is as close we can get to the actual colour used.
The 30.5cm M.11 below can be seen just outside the Museo Storico della Guerra in Rovereto in Northern Italy, one of the Worlds best WW1 Museums, in class right up there with the Imperial War Museum in London and the Army Museum in Brussels. This piece is one of just three surviving samples in the world of this truly feared piece of ordinance. And this specimen has really seen action, and at some really famous places. It was used from 1914 to 1918, at the following locations and/or battles (chronological order): Bzura Sucka, Sochazew, Visegrad, Przemysl, Zarki, Vhr, Gruska Jezierany, Kirli Baba, Dorna Watra, Jakobeny, Nesticanestia, Botos, Dolzak, Ceardari, Gorlice, Sonzo, Plava, Gorizia, Podgora, Doberdo, Folgaria, Ponta Corbin, Arsiero. Knowing the power of the M.11, this now rather peaceful looking machine must surely have been used to kill many hundreds if not even thousands of men.
The 30.5cm M.11 below was photographed in Belgrade (Weissenbourg for Austrians) at military museum in Kalemegdan fortress, just above the Danube river, where heavy fighting for the city between Austrian and Serbian forces took place in 1914 and 1915. The Skoda 305 could have been used in the operations. The one who took the photos - and also made the long climb up to the castle - is Ivan Stefanovic, and we all owe him for this chance to see photos of a gun much talked about but almost never seen. Thanks Ivan! The gun, that appears to be better kept than the one in Rovereto, is in deployed position. Note that the wheels are not attached to the lavette. Also notice the Barrel Wagon in the background - the only surviving sample in the world!
| Calibre | 305 mm |
| Min./Max. Elevation | +40°/+70° |
| Traverse | 120° |
| Weight Emplaced | 20830 kg |
| Weight of Light Shell | 287 kg |
| Weight of Heavy Shell | 380 kg |
| Muzzle Velocity | 340 m/sec |
| Max. Range (Light Shell) | 11,300 m |
| Max. Range (Heavy Shell) | 9,600 m |
The German firm of MGM has recently issued a Resin kit of this gun, and also kits to build the whole transport train of the 30.5cm M.11 - including the Tractor! See Kit Review section.
The following drawings were found in a French Intelligence Artillery summary from December 1917. The Italian Army captured an intact 30.5cm M11 in August 1917 and commissioned a set of drawings of the Morser as part of the technical evaluation of the piece. ( https://gallica.bnf.fr/ark:/12148/bpt6k6291407r/f67.image )
