The U.S. Army has introduced the M111, its first new lethal hand grenade since the Vietnam War, which uses blast waves instead of shrapnel to minimize collateral damage in urban combat.
Historical Background
- The M111 is the first new lethal hand grenade for U.S. forces since 1968, when the MK3A2 was introduced during the Vietnam War.
- The MK3A2 was retired in the 1970s due to asbestos content, which poses health risks like cancer.
- The current standard, the M67, uses shrapnel and is effective in open terrain but risks collateral damage in confined spaces.
Technology and Function
- The M111 employs blast overpressure (BOP) to kill or incapacitate enemies by vaporizing its plastic casing on explosion.
- It is designed for urban combat, allowing troops to clear indoor areas without enemies hiding behind walls, furniture, or appliances.
- The blast wave can cause tissue damage, rupturing eardrums, lungs, eyes, and gastrointestinal tracts; larger blasts may damage the brain or cause limb amputations.
Development and Military Use
- Developed based on lessons from Iraq War urban combat, where the M67's shrapnel risked friendly fire through walls.
- Propelled by RDX explosive, the M111 is palm-sized and cylindrical.
- The M67 will remain in use for open terrain to maximize fragmentation effects, while the M111 is designated for indoor use.
- The U.S. Marine Corps is separately acquiring the M21 blast wave grenade from Norwegian manufacturer Nammo.
Context and Comparisons
- Historical U.S. grenades include the Mk 2 "pineapple" from WWI, the M26 from the 1950s, and the M67 from 1968.
- Thermobaric grenades, which create fuel-air explosions and vacuum effects, are similar in concept but distinct in mechanism.