How blast-proof suits work

By Maggie Koerth-Baker at 8:25 am Tuesday, Mar 9

The protective suits worn by bomb diffusers in "The Hurt Locker" are real, right down to those fabulously popped collars, and they really do save lives. The secret is all in the materials, which provide a barrier against both shockwaves and shrapnel.

The overpressure wave is actually the more dangerous of the two. A microsecond after a bomb goes off, the explosion compresses the surrounding air and blows it outward in a lightning-fast shockwave that ripples through clothing and literally flattens internal organs.

The suit's rigid outer armor layer, the first and most important defense against this threat, is composed mainly of aramids: high-tech synthetic materials that are "strain-rate sensitive." In other words, "the faster something hits them, the harder they become," says Borkar. (Kevlar is simply the brand name of an aramid manufactured by DuPont.) The entire front-facing portion of the suit is reinforced from head to toe with hardened composites of two or more aramids, optimized for strength and lightness. This rigid layer can literally reflect or bounce some of the overpressure energy away from the technician, while also repelling flying fragmentation.

And that's only the first layer of defense. The suits have three total. The downside to all that protection: Weight. Each suit adds an extra 60 or 70 pounds, thus making it even more impressive that Staff Sgt. Jeremy Herbert, the explosive ordnance technician team leader for Marine Wing Support Squadron 271, has run a mile, wearing his suit, in nine minutes and 58 seconds.

Dvice: How Bomb-Proof Suits Work