Minenwerfer

The siege of Port Arthur in Russian-Japanese War (1904-05) showed that the fire of heavy guns alone was not sufficient to take a modern fortification, since not all obstacle could be cleared by them. It also took close-quarter weapons capable of dropping a heavy explosive charge exactly onto a target a few hundred metres away. This was true especially for barbed wire obstacles, which the artillery found troublesome to clear. On that basis the Engineer Committee of German Army in 1907-12 planned and built three kind of mine launchers: heavy, middle and light.

The main features of these weapons were:

- lower muzzle velocity compared to field or heavy artillery;

- scarce range of fire;

- not high weight ;

- shell with powerful explosive charge.

Indeed the effect of the shell of a 25cm Minenwerfer was equal to that of a mortar of 28cm or 30cm, which weighed more than ten times.

During the Balkan war the German officers who served with the Turkish Army against the Bulgarians recognized the possibilities of such weapons at Odrin and Chataldzha, and it was also on account of their reports that, before 1914, the Germans had already laid in a stock of them. At the beginning of the war German Army had 44 – 25cm and 116 – 17cm Minenwerfer. The 7.7cm Minenwerfer was tested before the war started, but was assigned to the units only at the end of the year.

They were muzzleloaders with rifled barrels that would recoil and normally fired at high angles above 45°, but in 1916-17 light Minenwerfer were adapted for horizontal fire and used as anti-tank weapons. Like the 42cm heavy mortars, they were kept in secret. A first they were loaded onto wagons for transport, but later they received road wheels and could be attached to artillery stile limbers or trailer by other horse drawn carts. Light MW could also be carried in several loads by pack animals. For shorter distances, Minenwerfer would be drawn on their wheels by their crews. In the trenches however, they had to be carried.

They showed their potentiality during the siege of Liege, Namur and Maubeuge and proved to be very useful also in trench warfare. Other Army had no mine launchers in 1914 and France had to press into service a range of ancient mortars dating to the beginning of 19th century, until more modern weapons were built. In 1915 German army made some experiments with mine throwers using compressed air. They were smooth bore breach loaders with calibres of 105mm and 150mm, but the companies armed with those weapons were soon disbanded.

The original task of Minenwerfer was to attack fortress. Heavy Minenwerfer were not intended to kill by a larger number of fragments of their shell, but to create a shockwave, which would move earth, and knock down walls or cave in roofs of strongholds. The high pressure, however, would even kill the crew inside a pillbox by entering through the embrasures. By their high angle trajectory they could fire behind cover. Without a delayed fuse, one shot would clear a wire obstacle of 10m diameter, with a delayed fuze, it would create a crater of 8 to 10 m diameter, 5 to 6 m deep. It would even cave in shelters 7 to 9 m below the surface. The medium and light Minenwerfer has been developed with farther ranges as counter-battery weapons to defend German fortresses in case the enemy had similar weapons.

Germany gave to Bulgarian Army only a little number of heavy and medium Minenwerfer. ASIK no 38cm ssMW (sehr schwere = very heavy) and no 24cm Flügel Minenwerfer were sent to Bulgarian Army. According with История на служба "Артилерийско въоръжение" в Българската армия 1878-1990 година, p. 97, on 15 September 1918 Bulgarian Army had 274 Minenwerfer (минохвъргачка) and 1158 Granatenwerfer (гранохвъргачка). According with Кратък обзор на бойния състав…, p. 118, Germany delivered to Bulgaria 284 light mine throwers, 162 medium mine throwers, 1932 grenade throwers. At that time the Minerwerfer were part of the Engineer troops : only in fall 1920 they were assigned to artillery. An Inspector of the mine throwers was appointed in the Army General Staff and every Army in the field had an officers in charge of all the mine throwers units assigned to the Army.

In October 1916 the Bulgarian Army raised its first Minenwerfer battalion. It was composed by three companies and one park half-company and was armed with 18 medium and 30 light Minenwerfer. A Minenwerfer unit with 8 weapons was also attached to the Storm battalion formed in November. A second Storm battalion was formed on 11 August 1918 with Field Army Order Nr. 1578. Like in German Army, Minenwerfer units were assigned to the Engineer Troops, and not to the Artillery. The great importance attributed to the Minenwefer as an offensive, but also as a defensive weapon especially on the broken ground of the Balkan front, pushed the Bulgarian General Staff to demand more Minenwerfer to Germany.

During 1917 all the Bulgarian Infantry Division raised a Minenwerfer company, except 1^st Sofyiska Division that raised two companies, and 8^th Tundzhaska Division that apparently had none (Field Army Secret Order Nr. 1053/11 September 1917). They were composed by 4 medium and 8 light Minenwerfer. New companies were raised during the winter 1917-18 and were assigned to the divisional Pioneer battalions, each of them having up to 3 companies. In May 1918, following the German example, the divisional Minenwerfer companies and the Minenwerfer Command of the pioneer battalions were dissolved and with them every infantry regiment raised a Minenwerfer company of three platoons, each with 4 Minenwerfer. The reorganization was not completed when the armistice took place. In the infantry regiments were formed grenade throwers detachments.

Date of the formation of Minenwerfer companies in 1917
1^st Sofiyska Division – 1^st company 2^nd company	1 May 16 August
2^nd Trakiyska Division	20 August
3^rd Balkanska Division	1^st February
4^th Preslavska Division	6 August
5^th Dunavska Division	5 August
6^th Bdinska Division	13 May
7^th Rilska Division	6 March
9^th Plevenska Division	4 August
10^th Belomorska Division	1 June
11^th Makedonska Division	1 June
12^th Infantry Division	14 August
Mountain Division	27 June
Mixed Division	1 September

Bulgarian Minenwerfer	Bulgarian Granatenwerfer

70mm Mortirka

Granatenwerfer 16

Lanz 9 cm Minenwerfer

Rheinmetall 7.58cm light Minenwerfer old pattern

Rheinmetall 7.58cm light Minenwerfer new pattern

Rheinmetall 17cm medium Minenwerfer old pattern

Rheinmetall 17cm medium Minenwerfer new pattern

Rheinmetall 25cm heavy Minenwerfer old pattern

Rheinmetall 25cm heavy Minenwerfer new pattern