This is how an Army mortar works (from an 11C)

The concept is easy and with a good crew, so is the execution.
Students in the Infantry Mortar Leader Course conduct mortar training on the 60, 81, and the 120mm mortars at Red Cloud Range, Fort Benning, Georgia.
Students in the Infantry Mortar Leader Course conduct mortar training on the 60, 81, and the 120mm mortars at Red Cloud Range, Fort Benning, Georgia. (U.S. Army/Joey Rhodes II)

Mortars aren’t glamorous. They don’t have the thunder of heavy artillery or the high-tech appeal of an F-35. But when a rifle squad is pinned down and taking effective fire, mortars are the most beautiful thing in the world.

For the grunts on the receiving end, the first sign is a soft “thoompf” from a direction they can’t see, followed seconds later by an eruption of steel and dirt. This is the infantry’s oldest and most reliable problem-solver, a simple system that wins fights with speed, audacity, and a little bit of high-school physics.

A well-drilled mortar section that really knows its stuff can turn an unassuming piece of earth into a firing point in minutes: plate down, tube up, sight leveled, numbers confirmed. The kit is artfully simple: a tube, a bipod, a baseplate, and a crew that treats micro movements like they matter. This is the infantry’s pocket artillery, a weapon that drops rounds on a steep arc to eliminate enemies who thought a hill or a building made them safe.

The Team for the Job: 60s, 81s, and 120s

Not all mortars are created equal, and the system comes in three main classes, each tailored for a different mission. The 60mm mortar is the lightweight of the group, often carried by infantry platoons for immediate fire support. Stepping up in weight class is the 81mm mortar, the middleweight slugger that offers a serious upgrade in range and explosive effect while still being nimble enough.

At the top is the heavyweight 120mm mortar, a beast typically mounted in a tracked vehicle that blurs the line into true artillery, delivering a massive punch to smash fortified positions: Keep it well fed and moving, and it’ll knock out any adversary within the first round. 

The Anatomy of the Gun Line

A mortar is nothing without its crew, though, and the entire system is built around the team’s flow. The whole weapon sits in the baseplate, a heavy metal dish that absorbs the weapon’s recoil. The tube is just a hardened pipe with a fixed firing pin at the bottom. Aiming is controlled by the bipod, where a gunner uses two handwheels to manage elevation and traverse. Their entire world lives in the bubbles of the sight aperture; if it isn’t perfectly level, the rounds won’t land where they’re told (although a skilled gunner knows how to “play” the bubbles).

The beginning of the end starts with the Assistant Gunner (AG), who holds the round. On the Gun Leader’s command, he simply drops it down the tube. It’s a system of shared responsibility. The gunner translates numbers into intricate turns of a handwheel, while the ammo bearer helps feed the beast by prepping rounds. Each man trusts the others to do their job flawlessly, because a mistake on the gun line can be disastrous downrange.

Cooking with Gas: Charges and Fuzes

Spc. Patrick Wilson (left) and Spc. Evaristo Garcia fire a 120 mm high-explosive mortar round during a coordinated illumination exercise at Forward Operating Base Mizan, Afghanistan, on Sept. 2, 2009.
Spc. Patrick Wilson (left) and Spc. Evaristo Garcia fire a 120 mm high-explosive mortar round during a coordinated illumination exercise at Forward Operating Base Mizan, Afghanistan, on Sept. 2, 2009. (U.S. Army/Sgt. Kris Eglin)

Around the tail of each mortar round, you’ll find removable propellant increments. To the mortarmen, they’re “cheese charges”, crescent-shaped packets of gunpowder that were full cheese-colored. The math is simple: add cheese to go farther, strip cheese to come closer. This, combined with the tube’s elevation, is how a mortar crew dials in the exact range.

The round itself can be told what to do when it arrives. Point-detonating fuzes explode on impact. Proximity fuzes detonate several meters above the ground, creating a lethal airburst of shrapnel. Beyond high explosives, crews can send illumination rounds to turn night into day, or use white phosphorus, “Willie Pete”, to create thick smoke screens that cover a friendly advance, or melt down enemy equipment. It’s all about choosing the right tool to ruin the enemy’s day.

Why We Still Need Mortars

In this era of tactical missiles and drones, the simple mortar system remains an infantry commander’s best friend. Forget about fancy engineering; this system is about filthy, nasty, aggressive effectiveness. Even if a pilot can drop a satellite-guided bomb on a grid coordinate, a mortarman can respond directly to the voice of a panicked squad leader in seconds, and it’s that intimacy that matters the most when the lives of your men are on the line.

A mortar section that knows its drills can put rounds on a target in under 90 seconds; a 120mm mortar can take out everything within 60 meters of the burst radius. Multiply this by ten, and you’ll get its shrapnel radius. It can deliver this up to 4 miles away. It’s almost not fair.

They don’t need a runway or a clear line of sight. They just need good information from the Forward Observer and a patch of solid ground. Master the fundamentals, plate, bubbles, sight, and charges, and the tube will do what it has for more than a century: show up on time and finish the argument.

Next: 9 reasons mortarmen are so deadly

Adam Gramegna Avatar

Adam Gramegna

Contributor, Army Veteran

Adam enlisted in the Army Infantry three days after the September 11th attacks, beginning a career that took him to Kosovo, Iraq, and Afghanistan twice. Originally from Brooklyn, New York, he now calls Maryland home while studying at American University’s School of Public Affairs. Dedicated to helping veterans, especially those experiencing homelessness, he plans to continue that mission through nonprofit service. Outside of work and school, Adam can be found outdoors, in his bed, or building new worlds in his upcoming sci-fi/fantasy novel.


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