Grenades and Mortars
As described in a report of the Prussian Engineer Committee
On 25 February 1909, the president of the Engineer Committee of the Army of the Kingdom of Prussia promulgated an overview of recent innovations in the realm of siege warfare. The following, which translates portions of this document, describes developments in the closely related realms of hand grenades, rifle grenades, pistol grenades, and trench mortars.
English words in bold type translate German words that were underlined in the original document.
Hand Grenades
Whether thrown by hand or fired by hand-held weapons, hand grenades are used against living targets.
The Hand Grenade Commission (Handgranaten-Komission) has built prototypes of a factory-made hand-thrown hand grenade and has begun to work on the development of grenades fired by hand-held weapons.
Operational units should practice the assembly and use of large numbers of improvised hand grenades. These should be simple types that use time or burning fuzes. This will allow the use of a variety of explosives and containers, thereby enhancing ease of assembly and the building of large numbers (of grenades).
Do not use impact fuzes.
A grenade should weigh about one kilogram (2.2 pounds)
To preclude the creation of fragments that might injure the thrower, the body of the grenade should be as thin as possible. The effect (upon the enemy) comes chiefly from the explosive.
This consideration does not apply to hand grenades designed to be thrown by men behind cover. These should use thick, cast-iron bodies, filled with small pieces of iron and such, to enhance their effect.
These two paragraphs may win the prize for the earliest expression of the distinction between ‘offensive’ and ‘defensive’ hand grenades.
Appendices I and II provide instructions for the building of grenades to be fired by rifles and flare pistols.
Appendix I
Rifle Grenade
Appendix II
Shooting Explosive Charges from a Signal Pistol, an Experiment Conducted by a Battalion
(The soldiers who built this projectile) …
placed one to three cylindrical charges (Bohrpatronen) into container made out of soldered tin,
fitted the shell with a pointed tip made out of cast tin and a base made out of wood.
put a five-second time fuze behind charges, one that reached back into the two or three grams of loose propellant placed in the chamber.
smeared the projectile with a thick lubricating agent of an unspecified type, thereby ensuring a tight gas seal
With the largest propellant charge, the projectile could reach out to two hundred meters.
When you experiment with projectiles of this type, take care to avoid premature detonations.
Wurfminen
We define Wurfminen as explosive charges thrown by devices that resemble artillery pieces.
Large Wurfminen, with charges weighing fifty kilograms or more, are usually used to destroy obstacles as well as cover made out of weak concrete, or, when possible, armored plate.
Small Wurfminen, with charges weighing one kilogram or so, are used against living targets and improvised cover.
Large Wurfminen
Operational units should experiment with the ‘earth mortar’ (Erdmörser) described in Appendix III. Needless to say, the accuracy (of this device) leaves much to be desired. Nonetheless, the important thing here is the detonation of the charge. One can use beer barrels, fitted with iron hoops that hold multiple time fuzes, to hold the explosive.
The Engineer Committee has built, for the Pioneer Siege Train and the equipment of fortresses large trench mortars (Minenwerfer) that fire one hundred and twenty kilo mines (which carry fifty kilo charges) with great accuracy out to a distance of three hundred and fifty meters. Operational units can use these results as a baseline for their experiments.
Small Wurfminen
We cannot recommend further research into mechanical throwing devices. The Engineer Committee has concluded that its own efforts in that regard have proved futile.
One battalion recommended the use of 8cm rescue rockets (Rettungs-Raketen) as a means of delivering explosive charges. After conducting a preliminary investigation, the Explosives Laboratory (Feuerwerks-Laboratorium) rejected this proposal. The rockets, it observed, proved highly inaccurate, hazardous to transport, and dangerous to handle.
The rockets mentioned here had been used for several decades to deliver lines to (or, to be more precise, on top of) ships in distress.
Source
Engineer Committee (Ingenieue-Komitee), Zusammenstellung der Erfahrungen über pioniertechnische Angriffs- und Verteidigungsmittel im Festungskrieg (‘Collection of Lessons Learned about Combat Engineer Equipment for Fortress Warfare, both Offensive and Defensive’) (25 February 1909) Folder PH 14 84 Bundesarchiv (German Federal Archive) pages 1-9
For Further Reading
Pistol grenades ...
Lots of ideas, some work out.
Do not use impact fuzes.
No. Don’t.