Security

Liquid Armor: From "Uban Legend" to Real Defense?

As we have seen, water can offer pretty good protection against bullets — so good, it could, one day, become the vehicle armor of the future. Today, American soldiers are jury-rigging up such defenses — despite their commander’s insistence that they were succumbing to an "urban legend." A Stryker crew had filled hundreds of five-gallon […]

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As we have seen, water can offer pretty good protection against bullets -- so good, it could, one day, become the vehicle armor of the future. Today, American soldiers are jury-rigging up such defenses -- despite their commander's insistence that they were succumbing to an "urban legend."

*A Stryker crew had filled hundreds of five-gallon water bottles with a mixture of sand and water and strapped them inside the vehicle's slat armor (the steel 'birdcage' designed to pre-detonate an RPG warhead) in an effort to protect themselves against an EFP attack. *

*"This is what [soldiers] are doing to try to stop it, and I'm trying to tell them: We tested this, it doesn't work," Fuller explained. *

My guess is that the idea may have come from a Norwegian invention, described in New Scientist magazine:

Tests carried out by the Forsvarets Institute in Norway have shown water is an effective barrier to high velocity bullets: they tumble and lose energy in it just like they do when they hit the body. So the institute is patenting (WO 2004/40228) a vehicle with several large flat watertight tanks built into its sides.

Each tank is thin, like a domestic radiator, and made from plastics or light metal and with a sandwich of several energy absorbing carbon-reinforced fibre sheets stacked inside. When empty, the sandwiches give no protection, but add very little weight. Before a risky journey, the tanks are filled with water. The institute reports that bullets from a rifle are easily stopped by the combination of fibre sheets and water.

It's an ingenious idea, and with some development it might even offer useful protection against something as large as an improvised EFP, which is unlikely to be as tough or as aerodynamically stable as a true military EFP. This makes it more likely to fragment or be turned by the impact with water, degrading its penetrating power enough for it to be stopped by the Stryker's armor.

Clearly five-gallon water bottles are not up to the job – but as with many urban legends, this one may have had a basis in the truth.