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Time-Delay Grenade Mechanics

Jun 23, 2025

Overview

This lecture explains the mechanics and design of time-delay fragmentation grenades, including how they function, their key parts, and operational challenges.

Time-Delay Fragmentation Grenades

  • The most common battlefield grenade is the time-delay fragmentation anti-personnel hand grenade.
  • Its primary function is to kill or injure enemy troops by launching metal fragments in every direction when it explodes.
  • The grenade's outer shell is made of serrated cast iron to enhance fragmentation.
  • Inside, a chemical fuze mechanism is surrounded by explosive material, poured in through a filling hole.

Firing Mechanism and Operation

  • The striker lever on top is kept in place by a safety pin to prevent accidental detonation.
  • To use, depress the striker lever, pull the pin, and throw the grenade.
  • Once released, the spring-loaded striker hits the percussion cap, creating a spark.
  • The spark ignites slow-burning material in the fuze, providing about a four-second delay.
  • The delay element ends at a detonator, which is then ignited, causing an explosion.
  • This explosion sets off the main explosive, shattering the grenade and propelling metal fragments outwards.

Advantages and Disadvantages

  • Time-delay grenades are durable, easy to use, and effective for area damage.
  • They may vary in timing (two to six seconds), making them somewhat unpredictable.
  • The delay allows enemies the chance to throw the grenade back before it explodes.

Alternatives to Time-Delay Grenades

  • Impact grenades explode on impact, removing the risk of enemies throwing them back.

Key Terms & Definitions

  • Time-delay grenade — A grenade that explodes after a preset delay, not immediately on impact.
  • Fragmentation — The process of breaking into pieces, causing damage by flying metal.
  • Fuze — The ignition system controlling the timing of the explosion.
  • Striker — A spring-loaded part that initiates the ignition.
  • Percussion cap — A component that creates a spark when struck.
  • Detonator — The device that causes the main explosive to go off.

Action Items / Next Steps

  • Review how the firing sequence of a time-delay grenade works.
  • Read the next section on impact grenades for comparison.