The 37mm Spade Mortar was a Soviet 37 mm light infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 mortar

Mortar (weapon)

A mortar is an indirect fire weapon that fires explosive projectiles known as bombs at low velocities, short ranges, and high-arcing ballistic trajectories. It is typically muzzle-loading and has a barrel length less than 15 times its caliber....

 used in the Second World War. The mortar was produced from 1939 until the end of 1941.

The weapon was a dual-purpose device in that it could also be used as a spade. When a leg was removed from the handle, the spade part of the weapon locked into position as a base plate for the mortar. The weapon was apparently intended to serve as a fire support weapon for every infantryman as it was designed to be operated by one man. There was no aiming device and the soldier simply pointed the mortar at its target. The soldier carried 15 rounds of ammunition on a fabric belt for the mortar.

The German Army designated the weapon the 3.7 cm Spatengranatwerfer 161(r), although the true Soviet designation was simply "37mm mortar" . The weapon was likely an attempt to boost the firepower of Soviet rifle units. Although a rifle grenade-launcher (which the Red Army also had) can fire shells of similar weight, they are slower to load and cannot serve as rifles while firing grenades. The spade mortar was used during the Winter War

Winter War

The Winter War was a military conflict between the Soviet Union and Finland. It began with a Soviet offensive on 30 November 1939 – three months after the start of World War II and the Soviet invasion of Poland – and ended on 13 March 1940 with the Moscow Peace Treaty...

 with Finland where the weapon was found ineffective in the heavy snow. Initially used in the Russo-German War, the spade mortar fell into disuse after 1942.

During the Iran-Iraq War

Iran-Iraq War

The Iran–Iraq War was an armed conflict between the armed forces of Iraq and Iran, lasting from September 1980 to August 1988, making it the longest conventional war of the twentieth century...

, the Iranian Army developed a similar device, the 37mm Marsh Mortar

37mm Marsh Mortar

The 37mm Marsh Mortar was a compact commando mortar developed by the Iranian Army during the Iran-Iraq War. It is very similar in concept to the WWII Soviet 37mm Spade Mortar...

 for use in marshy ground, as 37mm was the maximum shell size for which recoil

Recoil

Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gasses, according to Newton's third law...

did not drive the mortar into the soft ground.