Fahrpanzer

The Fahrpanzer was a mobile artillery piece made prior to World War I in Germany, implemented in several German fortifications from 1890 onwards and exported to several foreign military powers prior to the outbreak of hostilities.

Specifications
As designed the Fahrpanzer was mounted on narrow gauge railroad trucks and was wheeled along 60 cm tracks to its battle station. When not in use it would be pushed into a protective bunker to avoid damage during heavy bombardment. The Fahrpanzer was not autonomous: as originally designed it could only be pushed into place and rearmed from outside. It is not clear whether in practice any Fahrpanzer were retrofitted to be self-propelled or self-reloading. However artillery pieces of any kind were in short supply during World War I, and many Fahrpanzers were removed from their fortifications and installed in forward trenches by the Germans.

For road transport the Fahrpanzers had purpose-built horse-drawn carriages. All export models of the Fahrpanzer were sold with such a carriage, and it appears some export Fahrpanzer remained affixed to their carriages for the duration of their military career. All Fahrpanzer were fully armored and operated by a two-man crew. They may have been positioned and rearmed by the gun crew, or by handlers stationed outside the weapon. In any event the lack of self-propulsion and self-rearming capability placed its operators at risk. The Fahrpanzer could have benefitted from continued development to equip it with such capabilities, however the emergence of fully autonomous armored tanks on the battlefield effectively rendered the concept obsolete. A period illustration clearly showing several remote-controlled, machinegun armed Fahrpanzer engaged in trench warfare does exist, however no photos or documents exist to suggest the idea ever evolved past the conceptual stage. Armament consisted of one Grunson 5.3 cm quick-fire gun capable of +10 degrees and minus 5 degrees elevation, mounted in a 360 degree rotating turret. The gun could fire a 1.75 kg shell with a muzzle velocity of 495 m/s, and fire a maximum of 30 shells per minute. The shells were fed from inside by the two-man gun crew, who would be fully protected by the Fahrpanzer's armor until it ran out of ammunition. In practice the firing of the gun destabilized the Fahrpanzer badly, reducing the accuracy of the crew's aim.

The Fahrpanzer on display in the Army Museum in Brussels has long been cited as the only remaining example, however pictures of restored Fahrpanzers can be found originating from Bulgaria, Greece, Switzerland and South America. There are also numerous Fahrpanzers on display in the Polish Army Museum and Museum of Polish Military Technology, both in Warsaw.

Romania purchased 334 Gruson Fahrpanzers, in the 53 mm caliber. These were initially deployed on the Siret Line at Focşani (15 batteries, with 6 turrets each), Nămoloasa (24 bateries of 3-5 turrets), Galati (30 batteries of 6 turrets and 10 bateries of 3 turrets) and Brateş (10 turrets). The bridgeheads (not part of that Line) at Cernavodă and Turtucaia were equipped with 28 turrets, and the one at Silistra was equipped with 17 turrets. These guns remained in their emplacements for about twenty years, before being transformed in infantry guns between 1914 and 1916 by mounting them on Romanian-built gun carriages. A few were transformed in anti-aircraft guns.