The United States South Dakota II and Iowa class battleships have an outboard STS armored plate of 1.25 to 1.5 inches.
Heard it discussed both ways as both being effective as a decapping plate and not effective.
The US armored belts though work of the idea that a shell with hit the armor at a steep angle, both lessening the energy delivered to the belt by deflecting and the armor itself being thicker than it would otherwise be.
What I am curious is if the outer plate, assuming that the decapping effect does not work, would it cause the shell to increase its angle and therefore further reduce the energy striking the belt and to angle it such that the belt is effectively thicker.
So people understand how I am comparing armor thickness due to the shell's angle of fall compared to the belt armor.
Using the chart, a 4 degree increase in angle at 22 k yards vs the 16 inch would result in almost a 7% decrease in energy and about an inch of additional armor.
Edited by DesertFox, 31 October 2010 - 2019 PM.