Army Research Lab Show Off Latest Prototype of the ‘Third Arm’

The US Army’s ‘Third Arm’ first emerged in 2015, designed to redistribute some of the weight soldiers carry in their arms and shoulders to their abdomen. This, in theory, could make carrying heavy equipment and weapons over long distances much easier, lowering short and long-term impacts on troops’ health.

Recently engineers from the US Army Research Laboratory have been showing off the latest iteration of the ‘Third Army’. Mechanical engineer Dan Baechle, explained the concept: “It can help stabilize the weapon and take the load off of their arms,” he said. “It’s made from composite materials [including carbon fibre] to make it as light as possible, but also to ensure the range of motion that Soldiers need.”

Baechle explained that ‘Third Arm’ has been “tested it with the M249 and M240B machines guns. The M240B weighs 27 pounds, and we were able to show that you can take the weight of that weapon completely off of the Soldiers’ arms.” The latest version of the arm can allow soldiers to go prone with relative ease, something earlier prototypes could not.

The US Army Research Laboratory shared a video of the arm in action, demonstrating its ability to support an M249 and show the range of movement available to troops using the prototype:

Baechle noted that the arm was also getting a lot of attention online: “right now it’s a prototype device, and it’s a fairly early stage prototype device. It’s been getting a lot of interest higher up in the Army, but also online with some of the stories that have come out. We’re using some of the interest to help motivate further development of the device.”

Army Sgt. Michael Zamora assumes a prone fighting position using a prototype Third Arm exoskeleton device during testing at Aberdeen Proving Ground, Maryland, March 14, 2018. (Photo Credit: U.S. Army photo by Conrad Johnson)

The Army Research Lab is hoping a larger live-fire study with troops will happen later this year, following a small-scale trial in 2017. Baechle explained that user feedback drives their development of the arm and that he hopes “in the future what we’ll end up with is something that will help the Soldier. Whether or not it’s in the form you see today, that’s less important. Helping the Soldier is what I really hope for. I think this year is really going to be a good one and an important one in showing what this device can do.”