Air Force testing lighter, transparent ALON armor

“The metal front shield limits your view,” said Sgt James Murphy, 31, of Lavallette, N.J. “You should never have to stand up to see what’s going on around you. Right now, everything from your head to your chest is exposed.”


Cost concerns an obstacle to using new material in Humvees

By JEFF SCHOGOL | STARS AND STRIPES Published: October 30, 2005

ARLINGTON, Va. — The Air Force is testing a new, light-weight transparent armor that is much tougher and harder than the layers of glass currently used to shield troops, said an Air Force officer involved with research into the new armor.

While the Air Force is looking to employ the new armor on aircraft and other equipment, no government agency has started a program to use the stronger transparent armor to protect Humvee gunners, said 1st Lt. Joseph La Monica.

La Monica said that one stumbling block to using the new armor to protect Humvee gunners is its cost — about three to five times that of glass.

La Monica is head of research into the new armor at the Air Force Research Laboratory Materials and Manufacturing Directorate at Wright-Patterson Air Force Base.

He said the new armor owes its toughness to its ingredients including alumina, a ceramic found in the metal aluminum; oxygen and nitrogen; hence its name: ALON transparent armor.

It takes half as much ALON to stop a .30 caliber armor piercing round as it does glass, La Monica said.

As of yet, no government agency has come forward with a formal program to put ALON on Humvees, La Monica said.

“In the opinion of this office, the reason that ALON is not being used in Humvees is its cost,” wrote La Monica’s supervisor, Robert Ondercin, via e-mail. “It can be fabricated in Humvee sizes, but it is costly compared to bullet-proof glass layups.”

Glass costs about $3.25 per square inch, while ALON runs between $10 and $15 per square inch, he said.

But in the long run, the new transparent armor could save money, La Monica said.

Because it is lighter than glass, it would put less wear and tear on Humvee engines and would save on gas, he said.

However, ALON has not been shown to be effective in large panels and is currently only suitable for small windows, a Defense Department spokesman wrote in an e-mail.

“ALON use in large windows will require significant investments in manufacturing technology and test and evaluation to demonstrate the required protection factors, especially against a multi-hit threat,” the spokesman wrote.

Countering the spokesman’s comments, La Monica’s supervisor at Air Force Research Laboratories wrote in an e-mail that “large size” is a relative term.

“ALON can be fabricated in 25-inch lengths, and it can be tiled to larger sizes,” wrote Ondercin. “In the opinion of this office, the reason that ALON is not being used in Humvees is its cost. It can be fabricated in Humvee sizes, but it is costly compared to bullet-proof glass [layers].”

Ondercin wrote that Air Force Research Laboratories are trying to reduce ALON’s manufacturing costs to equal what it costs to put bulletproof glass on Humvees.

“This accounts for such items as wear and tear on vehicles due to the added weight and needed replacement due to permanent clouding of the glass in service due to sand abrasion from the use of the current glass product,” he wrote. “These issues would be greatly alleviated by the use of ALON, not to mention its greater ballistic protection.”

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