U.S. Army Yuma Proving Ground (YPG) recently conducted a characterization test of the Sling mobile mortar system. The mortar is a standard 120 mm tube with the sling system and fire control system mounted to the back of a military vehicle. The weapon can be automatically deployed and emplaced in less than one minute and fire up to 16 rounds in the first minute of fire, four rounds per minute for extended periods of time thereafter.
U.S. Army Yuma Proving Ground (YPG) recently conducted a characterization test of the Sling mobile mortar system. The mortar is a standard 120 mm tube with the sling system and fire control system mounted to the back of a military vehicle. The weapon can be automatically deployed and emplaced in less than one minute and fire up to 16 rounds in the first minute of fire, four rounds per minute for extended periods of time thereafter. (Photo Credit: U.S. Army photo by Mark Schauer) VIEW ORIGINAL

YUMA PROVING GROUND, Ariz. — The mortar, capable of firing projectiles at high angles, is the weapon of choice to fight back against opposing forces in mountainous terrain.

U.S. Army Yuma Proving Ground has been at the forefront of improving the venerable weapon for the 21st century, recently conducting a characterization test of the Sling mobile mortar system.

The mortar is a standard 120mm tube with the sling system and fire control system mounted to the back of a military vehicle: in the case of the test at YPG, a High Mobility Multipurpose Wheeled Vehicle. The weapon can be automatically deployed and emplaced in less than one minute and fire up to 16 rounds in the first minute of fire, four rounds per minute for extended periods of time thereafter.

Like all large mortars, the weapon packs a powerful punch. A high energy M933 120mm mortar bomb is capable of killing anything within a 60-meter radius of its impact and is able to send fragmentation as much as ten times as far. The weapon’s effective range is greater than four miles.

Testers want to use the item the same way as Soldiers but are bound by safety procedures such as remote firing. Mortar testing also involves drawing a safety fan around the gun position in which personnel are prohibited when a projectile is being fired. In a combat theater, Soldiers would park the vehicle, get a fire mission and hydraulicly deploy the mortar, which is already attached to a base plate.

“This system holds your cannon in place and acts as your bipod. It can traverse the canon 180 degrees,” said Matthew Lukas, YPG test officer. “The base plate is a little different from the standard — it has additional eye hooks to keep it in place when it is stowed. The base plate hangs off of a socket and needs a way to retain it.”

The weapon’s fire control system sets the weapon’s elevation and traverse before the Soldiers begin to fire. With the mission completed, the operators can hydraulically stow weapon and automatically lock the weapon in place before driving away.

YPG testers were particularly interested in verifying it could handle the stress of repeated firings without cracking or breaking. As is typical in mortar tests, the system was fired numerous times at different elevations and using rounds with different powder charges. The testers also fired rounds with excess propellant to put additional strain on the system as high-speed cameras recorded each mortar bomb as it launched from the tube. Two traditionally emplaced 120mm mortar tubes were fired in the same volleys to compare their range and accuracy.

“They’re trying to characterize the accuracy of the sling mortar compared to regularly emplaced mortars,” said Lukas. “We’re shooting strictly to see if the sling mortar matches the firing tables that already exist for the M933 cartridge.”