Original German WWI Model 1915 Inert "Turtle" Offensive Discus Hand Grenade - Discushandgranate

With the start of World War 1 in 1914, and its associated Trench Warfare battlefields, came the need for various weapons designed to unseat defenders from their positions. The hand grenade, a development of ancient warfare, found renewed value in the modern war and all sides strived to make for better infantry-level grenade weapons in an effort to gain the upper hand.

The typical grenades of the period were fuse-delayed but it was soon found that an enemy could simply grab and throw the grenade back in the direction of the attacker if the fuse ran too long (or failed altogether). As such, attention was given to development of impact-fuze grenades - those that detonated upon impacting a surface and therefore eliminating the threat of having the grenade thrown back.

The Germans managed an ingenious solution through their "Diskushandgranate Model 1915". As its name suggests, this grenade took on a disk-like design in which two sheets of metal (cast iron) were set over one another and crimped at the edges. The metal encapsulated bags containing the required explosives. Ignition was by way of a star-fish like internal assembly that held inertia blocks and percussion pins. A safety pin ensured that the device would not detonate prematurely.