What Puts Holes in Abrams M1A1 Tanks?

'Something' Felled An Abrams Tank In Iraq – But What? Mystery Behind Aug. 28 Incident Puzzles Army Officials. This story hasn't gotten nearly enough media. The M1A1 and M1A2 tank are mainstays of the US Army. And this M1A1 appears to have been holed by something new and somewhat mysterious.

Shortly before dawn on Aug. 28, an M1A1 Abrams tank on routine patrol in Baghdad “was hit by something” that crippled the 69-ton behemoth.

Army officials still are puzzling over what that “something” was.

According to an unclassified Army report, the mystery projectile punched through the vehicle’s skirt and drilled a pencil-sized hole through the hull. The hole was so small that “my little finger will not go into it,” the report’s author noted.

The “something” continued into the crew compartment, where it passed through the gunner’s seatback, grazed the kidney area of the gunner’s flak jacket and finally came to rest after boring a hole 1½ to 2 inches deep in the hull on the far side of the tank.

As it passed through the interior, it hit enough critical components to knock the tank out of action. That made the tank one of only two Abrams disabled by enemy fire during the Iraq war and one of only a handful of “mobility kills” since they first rumbled onto the scene 20 years ago. The other Abrams knocked out this year in Iraq was hit by an RPG-7, a rocket-propelled grenade.

Experts believe whatever it is that knocked out the tank in August was not an RPG-7 but most likely something new — and that worries tank drivers.

Mystery and anxiety

Terry Hughes is a technical representative from Rock Island Arsenal, Ill., who examined the tank in Baghdad and wrote the report.

In the sort of excited language seldom included in official Army documents, he said, “The unit is very anxious to have this ‘SOMETHING’ identified. It seems clear that a penetrator of a yellow molten metal is what caused the damage, but what weapon fires such a round and precisely what sort of round is it? The bad guys are using something unknown and the guys facing it want very much to know what it is and how they can defend themselves.”

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The soldiers of 2nd Battalion, 70th Armor Regiment, 1st Armor Division who were targets of the attack weren’t the only ones wondering what damaged their 69-ton tank.

Hughes also was puzzled. “Can someone tell us?” he wrote. “If not, can we get an expert on foreign munitions over here to examine this vehicle before repairs are begun? Please respond quickly.”

His report went to the office of the combat systems program manager at the U.S. Army Tank-automotive and Armaments Command in Warren, Mich. A command spokesman said he could provide no information about the incident.

“The information is sensitive,” he said. “It looks like [members of the program manager’s office] are not going to release any information right now.”

While it’s impossible to determine what caused the damage without actually examining the tank, some conclusions can be drawn from photos that accompanied the incident report. Those photos show a pencil-size penetration hole through the tank body, but very little sign of the distinctive damage — called spalling — that typically occurs on the inside surface after a hollow- or shaped-charge warhead from an anti-tank weapon burns its way through armor.

Spalling results when an armor penetrator pushes a stream of molten metal ahead of it as it bores through an armored vehicle’s protective skin.

“It’s a real strange impact,” said a source who has worked both as a tank designer and as an anti-tank weapons engineer. “This is a new one. … It almost definitely is a hollow-charge warhead of some sort, but probably not an RPG-7” anti-tank rocket-propelled grenade.

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OK, the M1A1 is a little long in the tooth (mid-80s mostly), overweight, and drinks fuel like crazy. In contrast, M1A2 is vintange 1993, overweight, a fuel hog, but carries improved armor.

Both types of tank have been deployed to Iraq. The idea that the tank has some vulnerabilities is not utterly new.

Coincidentally, another Abrams — the latest model this time — was taken out, a couple of days ago by a “roadside explosion”.