25cm Schwerer Minenwerfer (sMW) a.A.

Some of the Artillery pieces used by the German Army in the Great War were not, technically speaking, artillery pieces at all, but heavy mortars: and of these, that were employed in a big variety, the most important were the Minenwerfer (literally: "Mine Throwers") or medium mortars of 17cm calibre and the heavy dito of 25 cm calibre. The latter type was a much sought after support weapon, which is needless to say, as it could fire projectiles with an explosive power that was much greater than artillery projectiles of the same calibre. 

The reason for this is, that because of the relatively low pressures in the mortars barrel, as compared to, say, an howitzer equally big, the casing of the mortar projectile could be made thinner, allowing for a bigger load of explosives. A grenade from a sMW thus contained some 47 kilos of TNT, which actually equals the explosive power contained in almost 250 7.7cm early type of HE/Shrapnel grenades! Needess to say, used properly, the effect could be absolutely horrific. 

The Minenwerfer originally started as a specialist weapon for the Engineer branch of the Army, thought to be used primarily against obstacles hard to get at by traditional engineer means and by artillery. What the designers at Rheinmetall came up with, was essentially a scaled down howitzer, with a rifled barrel, a hydro-pneumatic recoil mechanism and a standard dial sight. It was, however, muzzle-loaded. At the outset of the war, some 44 of these heavy Minenwerfer had been issued to the troops, and being a well-kept secret, they came as a nasty surprise to the enemies of the German Army, first the Belgians - who were first subjected to them during the German attack at Liège and Namur, then to the French and British. 

One of the disadvantages of this very powerful mortar, was that the range was short, making it necessary to deploy the Minenwerfer in the very frontlines, making it vulnerable to all types of anti-battery fire and other counter-measures. Also, the muzzle velocity was of course quite low, meaning that the speed of the projectiles was equally slow: it was quite possible to see them coming, most of the time tumbling over and over high up in the air, with a very distinctive wobbling sound, making them easy to spot, meaning that the unlucky men at the receiving end had a fair chance to avoid them, if they could move about. The accuracy was not pinpoint, either. Some said that the effect of these mortars was principally moral, but that was a grave overstatement: they could wreak terrible havoc if the conditions were right.

        

The sMW was very heavy and cumbersome to handle: it took some 21 men to move it. It came equipped with special wheels, that were removed when the mortar was emplaced. Still, despite it's drawbacks, it was produced in great numbers. The reason was partly the effect: it was a fearsome weapon. But also, it made sense economically to employ this weapon. It was 10 times cheaper to manufacture than the 42cm Big Berthas, but it was almost equal in effect. (In addition to this, the ammunition were also cheaper, as it did not need any costly metal for the cartridge.) Mortars have always been the poor mans artillery, and it was very much so with the sMW.

       

The sMW was not a troop weapon per se, being used simply for local fire support, at the beck and call of the local commanders. The use of the gun was often strictly centralized, the batteries being tightly controlled by the artillery commanders, giving them the role of supplementing the ordinary artillery. In the attack, batteries of sMW were almost invariably used for making an enemy position "ripe for assault" - sturmreif. (All large calibre weapons were used for this. Field Guns and lighter Minenwerfers, were primarily used for supression or interdiction.) For instance, during the breaking of the Russian front at Riga, in early september 1917, around 100 had been gathered, and were used, with telling effect. 

Click on the thumbnails below, to see photos of a surviving sMW, to be found in the Army Museum in Brussels. (courtesy of Philippe Massin.)

       

Technical Data

Calibre	250mm
Weight of Gun	628 kilos
Maximum Range	2.6 kilometers
Muzzle Velocity	200 meters per second
Rate of Fire	20 rounds per hour
Weight of Shell	92 kilos

Modelling the 25cm sMW a/A

Fine Scale Factory makes the only kit of the 25cm sMW that I know of. Click here for a review.