CORRUGATED PLATING DEFLECTS ARMOR-PIERCING BULLETS (Jul, 1936)
CORRUGATED PLATING DEFLECTS ARMOR-PIERCING BULLETS
BY FURROWING the surface of metal plate with angular ridges, a Philadelphia inventor has materially increased the strength of armor designed for use on tanks, warships, and aircraft. In recent ballistic experiments conducted before ordnance experts, high-powered bullets fired from a distance of fifty yards pierced a test section of flat armor plate one half inch thick. When a slightly thinner section of corrugated armor was used, however, bullets fired from the same distance failed to penetrate its surface, but ricocheted off the sides. Armor penetration depends on a bullet’s angle of impact. Corrugated armor plate, the inventor explains, presents a surface inclined at an angle of forty-five degrees; bullets strike it a glancing rather than a direct blow.
I’ed think getting a decent shot going at speed would be impossible...
This is one of those cases when something looks as if it should work, but there must have been some reason against it or we would be seeing it everywhere. What is wrong with it, though, I can’t see myself.
Comment by Stephen — August 12, 2011 @ 5:40 am
Stephen – My guess is that it probably adds ungodly amounts of weight without offering enough protection against armor-piercing shells. Still, the concept does seem sound.
I love the look of that tank, too. Very Art Deco.
Comment by Scott B. — August 12, 2011 @ 6:02 am
Maybe it was good against antitank rifles, but offered a higher contact surface to explosive cannon shells? (meaning more shrapnel released inside the tank)
Comment by The_WOZ — August 12, 2011 @ 8:04 am
Probably this was abandoned when larger rounds were brought in, but the idea of angling armour is a good idea, look at the T-35.
Comment by Hirudinea — August 12, 2011 @ 9:06 am
Angling armor on a larger scale was more practical, worked better against larger rounds, and was easier to implement with thicker armor.
Angled armor works in many different ways. It increases the cross sectional thickness without increasing weight. It increases the area of contact of a projectile, therefore spreading its energy. It deflects some of the energy of the projectile increasing the chance of ricochet.
Comment by JMyint — August 12, 2011 @ 9:19 am
My guess is the idea simply became obsolete with the development of modern composite armour, such as Chobham, which is far more effective with a lot less weight.
Comment by Paul — August 13, 2011 @ 8:37 am
Paul: It was obsolete at the birth. Any kind of explosive shell would have penetrated that. Chobham was developed in the sixties and there were no armored vehicles using corrugated armor in WW2 as far as I know.
Comment by Jari — August 13, 2011 @ 4:18 pm
The concept of sloped armor goes back at least as far as the Civil War when people began really thinking about armor scientifically. The Merrimack/Virginia got its distinctive ‘floating barn roof’ look because its sides were sloped to help cannon balls ricochet off. As an added measure, they covered them with pork fat to make them slippery. (This was quickly found to be unneeded.)
Comment by Sean — August 15, 2011 @ 4:56 am
grandfather of the batmobile/trumbler,B-2 and F-111!
Comment by J Paul — August 15, 2011 @ 8:21 am
Jari: There was the magnificence, that was the Bob Semple Tank.
Comment by Maunicio — August 22, 2011 @ 6:59 am
Maunicio: I’d rather use the word “monstrosity”. What I gathered around the net, it wasn’t exactly successful as a tank….
Comment by Jari — August 23, 2011 @ 9:18 am