Unexploded grenade from a mine thrower

This grenade from a German 76 mm mortar never exploded and appeared intact in the surroundings of the University City (Madrid) some 78 years after the end of the Civil War.

Modern mortars became widespread in the context of the First World War, where small and light artillery pieces that could be handled in the narrow fortifications of the frontline, and capable of firing at 90º were necessary.  The Erhardt-system 76-mm mine-launcher entered service with the German Army in 1911 and was originally designed as a siege weapon, based on experiences from the Russo-Japanese War (1905). During the Great War, however, it was employed as a trench mortar by infantry units. It fired a 4.6 kg grenade at a distance of 300 meters. During the Civil War it was used by both sides: Republicans acquired them from the Soviet Union; the rebels by capturing Republican material or directly from Germany. The first to arrive in Republican territory: 126 pieces and 6,290 projectiles, entered Spain in February 2, 1937.

The Minenwerfer was an ideal weapon for the University City in Madrid, where a labyrinth of trenches, sometimes separated only a few meters, emerged after the Battle of Madrid (8-23 November 1936). The surroundings of the University Hospital were fiercely contested: attack and counterattack followed each other until the last weeks of the war, trench artillery playing a key role. In aerial photographs taken immediately after the end of the war the surface perforated by craters left by the explosions of artillery grenades can be clearly made out around the University Hospital, and archaeological surveys in the area uncovered abundant unexploded ordinance, including different models of mortar rounds. There is always a percentage of grenades, at least 10%, that do not explode, but in the case of sandy soils, like those of the University City, the percentage increases exponentially.

The Minenwerfer is a fine illustration of the kind of weaponry with which the Spanish Civil War was fought, especially during its early phases: heterogeneous and obsolete. Although both sides received more and more modern material as the war progressed, the truth is that heterogeneity remained one of the defining traits of the conflict, particularly for the Republican side. Mortars like the Minenwerfer also remind us that the Spanish Civil War was, in many ways and in many frontlines, a repetition of the First World War and its modalities of combat.