Articles about this robotic Squad Mission Support System, or robo-jeep, have been floating around a couple days now.
In case you didn’t see this, Army is set to sent four Lockheed’s Squad Mission Support System (SMSS) robot jeeps to Afghanistan where they’ll haul supplies for troops. The trucks are being sent there as part of a test program to see just how useful robot cargo trucks can be. The 11-foot long trucks can carry a half a ton of supplies for up to 125 miles after being delivered to the field in a CH-47 or CH-53 helo.
The SMSS can either lock on to and follow the 3D profile of a soldier using its on-board sensors or it can use GPS to navigate along a pre-programmed route. Oh, and yes, there’s still the option for a man to hop in and drive it.
At about a half a million a pop, that’s a pretty expensive proposition. And it doesn’t solve the problem of the fact that there are a lot of places light infantry go that no vehicle can follow. And that very terrain where the vehicle can’t go tends to be the places where reducing the loads on an infantryman’s back would do the most good, such as extremely steep terrain.
This isn’t exactly a new problem, either. Jeeps, of course, were a handy way to move a lot of stuff around the battlefield, but even so, they were pretty large and heavy, and only had a rated payload of 500 pounds. So the Army set out to find an even better vehicle to support light and airborne infantry. The result was a mechanical mule.
The M274 Mule served from about 1957 to the very early 1980s.
The entire concept of the Mule was to make the lightest, simplest vehicle possible to carry loads. The vehicle was a simple aluminum or magnesium alloy platform. It had a tiny air cooled 2 or 4 stroke engine, no suspension beyond low pressure tires and a little padding on the driver’s seat, and a dirt simple three speed manual transmission. But its 4-wheel drive and 4-wheel steering gave it decent off road mobility. It also had a very impressive load capability. With an empty weight of about 860 pounds, it was rated for a load of 1000 pounds. One Mule might not be able to carry the entire load of an infantry platoon, but you could fit a pretty goodly resupply of water, rations and ammunition on one. And it was simple enough that maintenance was easy even for troops with only the most minimal mechanical training. It also didn’t hurt that the vehicle was dirt cheap.
The Mule was used for more than just carrying supplies. Especially in airborne units, and in the Marine Corps, where weight and space were at a premium, Mules were used as prime movers for supporting weapons. One commonly seen weapon was the 106 mm recoilless rifle mounted on a Mule. The 106 mm RR was the main weapon of the anti-tank platoon of the airborne infantry battalion. Mounted on the Mule, the platoon was able to rapidly move the weapon, crew, and a ready supply of ammunition throughout the battalion area. Other weapons the Mule carried included company 81 mm mortars (though these were dismounted for firing), and occasionally M2 .50cal machine guns. Later, some Mules mounted the M220 TOW missile system.
As handy as the Mule was, it wasn’t without its problems. First, while it wasn’t road bound, it was restricted to the terrain it could traverse. No vehicle, especially a wheeled vehicle, can go everywhere. Like I said, that’s where the infantry really needs something to carry the load.
Also, the Mule was a pretty dangerous vehicle. There was absolutely no protection for the driver. With a fairly high center of gravity and all wheel steering, it wasn’t hard to flip the vehicle over, crushing the driver. An accident at the top speed of 25 mph could easily have fatal consequences. Proper training could mitigate this to some extent, but young troops who have only been driving civilian cars for two or three years, and unused to operating off road were often convinced of their invincibility, and all too often disregarded proper procedure with painful consequences.
After the withdrawal of the Mule from service, light forces either used Humvees, or carried their loads on their backs. But for many purposes, the Humvee is simply too large, and for many others, using soldiers as pack animals wasn’t entirely practical either.
Eventually*, the Army started using small numbers of commercially available utility vehicles to carry loads, particularly for airborne and air assault units. One popular model was the GATOR-M, which has seen use in Iraq and Afghanistan.
I’m certainly dubious that providing an autonomous supply vehicle is worth the investment in development costs or production expense. The vehicle, even if it does work perfectly, will still face the problem that it cannot traverse the very terrain the infantry needs to conquer.
If you really want to provide a means of transporting heavy loads where the infantry goes, you will have to revert to an older technology, older even than the Mechanical Mule.
*Long after I’d left- I always had to carry heavy loads on my back!