Army Testing New Version of Third Arm Device

It takes almost all the weight of a firearm off a soldier's arms, reducing fatigue and increasing accuracy.

The Third Arm device takes almost all the weight of a firearm off a soldier's arms and increases stability and accuracy.
The prototype Third Arm device takes almost all the weight of a firearm off a soldier's arms and increases stability and accuracy.photo courtesy U.S. Army

In April of last year, we posted a story about a "third arm" device that was being tested by the U.S. Army that would lessen the physical burden placed on soldiers on the battlefield by taking most of a firearm's weight off their arms.

The thing is, the device itself might shift the weight of a given firearm, but it adds more overall weight to a soldier’s load out.

The post got a fair amount of ridicule on social media, with a lot of readers saying it was absurd and had no place on a battlefield.

Well, it looks like the Army didn't agree. This press release says the U.S. Army Research Laboratory at Aberdeen Proving Ground in Maryland is moving ahead with testing of an "early stage prototype device" that looks like a more advanced design of the third-arm device from 2017.

“Third Arm is a wearable, passive, stabilizing device for the dismounted soldier,” Dan Baechle, a mechanical engineer at Army Research Laboratory, said in the video.

The story addresses the same concerns many commenters did, saying, “weight is a sensitive subject for ground troops, many of whom  likely see the Third Arm device and assume — rightly so, at this point — that it’s just more cumbersome gear added to their kit.”

But, as the engineer says, this is all about testing new things.

“What we want to look at here is [whether] there is a trade-off between potentially added weight and improved lethality, improved survivability,” Baechle said in the video.

It seems they have made quite a bit of progress.

Baechle said the Third Arm helps stabilize a firearm and does takes the load off the arms, and that its made of composite materials to keep it as light as possible and is designed for the widest range of motion possible.

The current Third Arm weighs less than four pounds, and has been tested with the M249 and M240B machine guns.

Baechle says the device took the full 27 pounds of weight from the M240B off a soldier’s arms when tested. That’s impressive, and those extra four pounds might be worth the added stability and reduced fatigue.

The new version of the prototype Third Arm allows for firing from the prone position, something the design from 2017 couldn't do.
The new version of the prototype Third Arm allows for firing from the prone position, something the design from 2017 couldn't do.photo courtesy U.S. Army

The ARL learned a lot from the prototype that was tested in a pilot study, which included live-fire tests, in 2017.

The results showed the device increased accuracy and reduced arm fatigue, but there were notable complaints from the testers.

Soldiers reported that the previous version of the Third Arm made it impossible to fire from the prone position—a pretty big problem in combat.

The press release from ARL says the new reworked device has addressed the issue and can be brought down into the prone firing position.

"We're still refining the device,” Baechle said, adding that they’re “starting to look at heavier weapons.”

As we’ve reported before, the U.S. Military, including the Army, is developing load-bearing exoskeletons, which could someday be used in conjunction with something like the Third Arm to drastically change the way troops interact with their equipment on the battlefield.

In May we reported that the U.S. Special Operations Command (SOCOM) has been working on a high-tech battle suit for special operators that would provide power and resiliency beyond normal human capabilities. The project is reportedly just one year away from actual testing.

This story from ArmyTimes.com says soldiers with the 10th Mountain Division will be the first to test a long-awaited exoskeleton that is desinged to reduce injuries, carrying loads, and help troops move around the battlefield with ease like something out of science fiction. If you've read Starship Troopers or seen Edge of Tomorrow, you get the idea.

The story says the U.S. Army Natick Soldier Research, Development and Engineering Center partnered with the division in February to identify, evaluate and transition exoskeleton technology to the Army.

"NSRDEC has led exoskeleton efforts for the Army for a number of years. One of the more advanced products that will soon hit the division is made by Lockheed Martin."

Army Times says company officials said the ONYX device will go through testing phases beginning as early as this fall.