The Army Wants Armored Turrets Packing 120mm Mortars For Its Strykers And Other Vehicles

The service says it wants better mobile mortars, but it could add suicide drones to the mix in the future, too.

byJoseph Trevithick|
Loitering Munitions photo


The U.S. Army wants a new turreted 120mm mortar that it can put on various armored vehicles, such as the Stryker and the up-coming Armored Multi-Purpose Vehicle. The service is also eying it as an option a variant of the future Next Generation Combat Vehicle and wants the complete system to eventually be able to fire loitering munitions, too.

The Army’s Picatinny Arsenal in New Jersey described its basic requirements for such a system in a notice that it posted on FedBizOpps, the U.S. government’s top contracting website, on Aug. 2, 2018. The announcement said the service hoped to find a company to develop the system, formally called the Future Indirect Fire Turret (FIFT), and begin production by the end of 2021.

“The 120mm Mortar FIFT is a 120mm turret that provides protection from enemy counter battery systems and insulates soldiers from the effects of both noise and blast overpressure,” the Army explained. “Additionally, the FIFT shall feature a level of automation, such that physical burden on crew is reduced, while supporting a high rate of fire capability.”

This new system would replace wheeled M1129 Stryker Mortar Carrier Vehicles and tracked M113-based mortar carriers. These existing designs both use 120mm mortars mounted inside the hull of the vehicle and fired through large hatches on the roof that expose the crew to enemy fire and other potential hazards.

An M1129 Stryker Mortar Carrier Vehicle. A member of the vehicle's crew and the mortar's 120mm mortar's muzzle are visible at the rear protruding through the large open hatch., US Army

The requirements say the turret can be manned or unmanned and needs an automatic loading system that at least moves the mortar rounds from a rack into the weapon itself. The objective goal is to acquire a system that doesn’t require a human to move the ammunition around inside the vehicle at all.

This desire for automation extends to the firing process, as well. The Army wants a gunner to be able to receive a request for a fire mission and respond within 30 seconds with the help of a ballistic computer.

If the vehicle is on the move when it gets the call for support, the service wants the crew to be able to stop, get into position, and fire the first round within a minute. There is a hope that the weapon system might even be able to work without the vehicle having to stop at all. This would make it more flexible and more survivable since it would be harder for an enemy to determine its position and then fire its own mortars or artillery in response.

The entire system needs to be relatively fast, too. The Army wants the turret to be able to lob 16 rounds in a minute if necessary, followed by a more sustained fire of 6 rounds per minute thereafter. The objective is for a crew to be able to get up to 24 rounds in the air in the first 60 seconds and then keep firing 12 rounds every minute indefinitely afterward.

A US Army soldier prepares to fire the 120mm mortar in an M1064 mortar carrier, which is based on the M113 armored personnel carrier., US Army

This volume of fire has to translate into so-called “Multiple Round Simultaneous Impact” fire missions, or MRSI, with at least six rounds hitting the same target area, or bursting overhead, within four seconds of each other. This would enable a single vehicle to saturate an area and give an opponent little time to react and try to seek cover.

The system needs to be able to engage targets at ranges of at least 5 miles, which is roughly equivalent to the capability of Elbit’s Cardom Recoil Mortar System 6-Light, or RMS-6L, on the existing mortar-carrying Strykers. The required minimum range, including for direct-fire targets, is no more than 220 yards.

A prototype of BAE System's Armored Multi-Purpose Vehicle, which the Army says would also receive the new mortar turret., BAE Systems

Not surprisingly, the Army wants the new weapon to be able to fire all of its existing 120mm ammunition, but it has also left the door option for future developments, which could include precision-guided types. The service is also interested in the mortar having a direct-fire capability, as well as an indirect one, which would require new types of rounds.

The most immediate option would be for Elbit, or another firm, to develop a full-enclosed turret and ammunition handling arrangement for the RMS-6L and improve the existing computerized fire control systems. Army crews in the Stryker mortar carrier variant and special operators using versions ground-mounted firing platforms, also known as the Enhanced Mortar Targeting System (EMTAS), can already move their weapons 180 degrees left or right from its existing position in just 12 seconds with the existing system.

The Army has also been experimenting with a mobile and highly automated 81mm mortar, known as the Automated Direct Indirect-fire Mortar, or ADIM, which it might be able to scale up to 120mm. This system has proven to be complex and expensive, though, which might push the Army to look at more readily available options if it wants to have something in production within three years.

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The service requirements actually seem very close to the capabilities already present in Finnish defense contractor Patria’s NEMO – a contraction of “NEw MOrtar.” This is an unmanned turret with a 120mm mortar capable of direct and indirect fire that features an automatic loading system and can fire bursts of three rounds in 12 seconds at targets up to six miles away. It’s a smoothbore weapon, just like the Army's present 120mm mortars, which means it should be able to fire the same ammunition.

Its maximum one-minute rate of fire is 10 rounds, which wouldn’t meet the Army’s requirements, but its sustained rate of fire of seven rounds every 60 seconds would. But it’s definitely a good starting place. NEMO is already in service in various countries on 8x8 wheeled armored vehicles similar to the Stryker and even small boats and demonstrated a shoot-on-the-move capability. 

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In 2016, Patria unveiled a containerized version that could fit on the back of a truck and that troops could emplace as a fixed firing position, a configuration that might make the weapon even more appealing to the Army. Since at least 2015, special operators have been interested in a mobile version of the EMTAS to give that system more flexibility. A truck-mounted NEMO could offer significantly more capability with added mobility for extended operations in remote areas.

The Army is also interested in building in additional growth potential into any FIFT system. It wants the turreted mortar to be able to, in some fashion, accommodate loitering munitions, such as the Lethal Miniature Aerial Missile System (LMAMS) or Single Multi-mission Attack Munition (SMAMS). These are the service’s names for the AeroVironment Switchblade and the Raytheon Coyote, respectively.

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It’s not clear whether or not the Army is talking about being able to fire these drones from the mortar itself, or if it just wants the FIFT to be able to also mount a separate launcher. Raytheon has already developed a four-tube SMAMS launcher as part of a separate truck-mounted system that the Army plans to use to knock down small unmanned aircraft.

Regardless, integrating the loitering munitions could significantly increase the overall capability of the Army’s mortar carriers. Beyond just offering the crew another means of attacking the enemy, the drones could help search for targets or offer additional local surveillance and defense around the firing position.

The SMAMS can act as a swarm and could potentially carry electronic warfare systems or other payloads in the future, as well. This could ultimately turn the Army’s mortar carriers into more multi-mission vehicles that could launch non-kinetic attacks or conduct limited surveillance and reconnaissance missions in addition to providing traditional fire support.

This sort of self-contained multi-purpose capability could be especially valuable in future expeditionary or distributed missions where relatively small units might find themselves operating for extended periods of time detached from traditional supporting ground, surface, and air assets. This would be a particularly likely scenario in the Pacific region, where ground forces could easily end up conducting operations spread out across a wide area, such as a chain of islands.

It’s a capability that could also be attractive not only to special operations forces, but to the U.S. Marine Corps, which focuses heavily on these types of operations and just recently retired its own 120mm mortar system. It is now in the process of exploring other fire support options, including rocket artillery and loitering munitions.

So, whether the Army decides to pursue a system based on its existing RMS-6L or chooses a new weapon, such as NEMO, the vehicles carrying these turrets could significantly increase the capabilities of its combat units beyond just giving them access to an improved mortar system.

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