Internal combustion is loud and so is war.
The roar of vehicles is as expected a part of modern combat as the booms from explosives and the staccato ring of gunshots, but not all of war has to be. Electrical engines are quiet, and especially against the din of battle, the softer sounds of a humming electrical engine can achieve something like stealth. In this light, Textron’s Grizzly unmanned ground vehicle could fine a quiet niche on future battlefields.
Despite its ursine namesake, the Grizzly is fundamentally a pack animal, more than a deadly foe. It is a mule-drawn cart in function if not form, a tracked platform built to lighten the loads of the soldiers it accompanies into battle. The Grizzly is a tracked vehicle powered by a hybrid diesel-electric engine, and aimed at the Army’s “Squad Multipurpose Equipment Transport” (SMET) program.
For the SMET program, the Army wants a vehicle that can carry about 1,000 pounds worth of soldier equipment — likely lightening the loads of nine soldiers across an infantry squad. In summer 2018, the Army tested multiple robot-wagons by having them transport nine rucksacks, six boxes of MREs and four water cans, or roughly the long-range load for a unit of light infantry. (Developed by Howe & Howe, the Grizzly participated in the 2018 exercise as the RS2H1. Textron acquired Howe & Howe in December 2018)
The SMET program wants the robots to be able to travel 60 miles over three days, and it must also be able to provide a spare kilowatt hour of power while moving, and at least 3 kilowatt hours while stationary. According to Howe & Howe, the Grizzly performed a 60-mile trek in less than half the time required.
The Army is set to makes is selections in the SMET program next month, and if a showing of the Grizzly in its booth at a tradeshow in March 2019 is any indication, Textron is optimistic about its robot’s chances. There remains the chance that the Army will decide the technology just isn’t there yet for any machine, and hold off on any of the robots for the near future. They wouldn’t be the first service to do so; after years of work and tests in exercises, the Marine Corps ultimately turned down the Legged Squad Support System, a robot mule designed to carry rucksacks on the march, for being too loud in the field.
Infantry is quieter than most, and if a SMET-selected robot, like perhaps the Grizzly, can operate electrically at the same volume or quieter than the soldiers around it, that’s a boon.
Kelsey Atherton blogs about military technology for C4ISRNET, Fifth Domain, Defense News, and Military Times. He previously wrote for Popular Science, and also created, solicited, and edited content for a group blog on political science fiction and international security.