The Army's Banana Peel Weaponry

The Army’s new XM1063 artillery round will "suppress, disperse or engage personnel" over a wide area and "deny personnel access to, use of, or movement through a particular area, point or facility." But how does it work, really? Some believe it’s a kind of chemical weapon; others have suggested an anti-traction agent that will coat the entire area with instant banana peel so it becomes more slippery than an ice-rink and controlled movement (by people and vehicles) is impossible. 

US Army work in this area goes back at least to the Korean War. But the latest round of research dates back to the 1990’s and the rise of weapons that are designed to hurt, not to kill. Previously known as the Non-Lethal Slippery Foam Program, it is now referred to as the Mobility Denial System.

One of the best sources for hard facts in this slippery area come from work done by the SouthWest Research Institute and the Army’s Edgewood Chemical Biological Center, with some interesting observations:

– People can walk on surfaces with a COF [Coefficient of friction] <0.4 and surfaces more slippery than ice, if they know of the hazard. It is the unexpected slippery spot that produces a COF < 0.2 that causes slips and falls.

– It is not the COF that determines the difficulty of crossing a slippery surface, it is the localized spots that are more slippery than the rest of the surface.

Unlike in James Bond, it’s not simply a case of squirting some oil in front of oncoming vehicles, though oil is one of the substances considered:

During prior studies by SwRI, it became apparent that a low coefficient of friction (COF) is only partially essential to assure denial. Rheology [that’s the study of the flow of matter under stress, as if you didn’t know], mass, and film thickness are also critical values for resistance to displacement by foot or vehicle traffic. A thin film of slippery material of any viscosity (low or high) is only effective against rapid motion or high speeds where hydroplaning or low displacement of lubricant films occurs.

To effectively address all speeds, masses, and profiles interfacing with the lubricant and the substrate, the film thickness and resistance to displacement by foot or vehicle movement must be considered together with COF. Initial screening studies suggest a film thickness of approximately 100-150 mils (0.010 to 0.015 inches) with sufficient stiffness to resist vertical displacement, is necessary and applicable to all target areas.

Such a film… should prove to be equally effective against all types of terrain and surfaces identified in the military’s requirements.

The key factor here is the thickness. Multiply it by a hundred meters square – the area covered by the XM1063 round – and you get a volume of more than two thousand liters. That’s far too great to fit into a single 155mm artillery round. Even if coverage is a small fraction of the total to produce ‘slippery spots,’ the volume is too great.

But work in this area continues, most notably DARPA’s Polymer Ice Program:

DSO is developing the Polymer Ice Program, which aims to replicate the properties of “black ice” for use in a broad range of hot, arid environments as found in the Middle East. The polymer-based artificial ice material will achieve effective mobility control by the precise and reversible reduction of ground traction. A non-toxic reversal agent will also be developed for both man and machine to achieve instantaneous traction restoration on contact.

It sounds like a worthwhile aim; even though the use of this type of material is likely to be fraught with all sorts of problems — it might very easily cause fatal vehicle accidents, for example. But I’m not convinced that the technology is in place yet.

(Picture Credits: US Army, DARPA)