Influence of hand grenade weight, shape and diameter on performance and subjective handling properties in relations to ergonomic design considerations.

Three hand-grenade design factors, namely shape (ball, oval, can), diameter (55, 60, and 65 mm) and weight (300, 400, and 500 g), were assessed. The objective criteria were (1) throwing distance from the grenade stop point to throwing point, and (2) error distance from the grenade stop point to the target. The subjective criteria were (3) the overall rating of handling (to hold and control) properties and (4) the rating of perceived exertions of throwing strength. Twenty ROC Army soldiers threw a Mark II practice grenade to familiarize them with the throwing procedure, and then, while standing, threw 21 experimental, mockup grenades at a target indicated by a flagpole 40 m away from the throwing point. Grenade weight had the greatest effect on both subjective and objective criteria. The 300 g grenade had the greatest throwing distance (38.6+/-6.5 m) and had the greatest accuracy (6.9+/-3.9 m). Grenade shape was also a significant influence based on both the subjective and objective criteria; with the ball shape being the best. Grenade diameter, within the range tested, did not affect either the subjective or objective criteria.