Type 91 Grenade - Background and Development

Background and Development

The Japanese Army, noting that grenades were short-ranged weapons, began efforts to optimize these weapons for close-in infantry fighting. The first hand-thrown fragmentation grenade was the Type 10. Soon after introduction of the Type 10 grenade to front line combat troops, a number of issues arose. When hand-thrown, instability and inaccuracy of the fuse mechanism made the Type 10 almost as much of a menace to the thrower as to the recipient. Furthermore, the weapon was regarded as undersized, and lacked desired lethality. In 1931, the Army Technical Bureau developed an improved version intended to address these issues. After carefully studying employment of grenades and mortars on the battlefield, the Japanese Army developed a unified system of hand grenades, rifle grenades, and grenade/light mortar shell dischargers ideally suited to warfare in typical short-range combat environments such as urban, trench, and jungle warfare.

As part of this concept, the Japanese Army had adopted by 1932 a set of fragmentation grenades with almost universal adaptibility. The Type 91 fragmentation grenade could be thrown by hand, fired from a rifle via a spigot-type launcher, or used in a mortar-like grenade discharger, the Type 89.