Shot trap
A shot trap is a location on an armoured vehicle where, depending on the angle of impact, an impacting shell that fails to penetrate may bounce off in such a manner that it hits another area of the vehicle where it is more likely to cause damage to the vehicle and/or injure its crew. Areas on the vehicle where the described phenomenon can occur may be referred to as shot traps, and should obviously be redesigned.[1]
For example, initial turret design of the Panther and Tiger II tanks had a curved gun mantlet and a curved turret front plate respectively, both with a thickness of 100mm. The lower part of the armour plates acted as shot traps by deflecting incoming shots downwards towards the hull roof (16-17mm thick on the panther, 40mm on the Tiger II), or into the turret ring where the shell could potentially jam the traverse mechanism. On the Panther a new flat "chin" on the mantlet solved the problem. The Tiger II production turret did not feature the curved front of the early turret, instead using a flat 180mm plate sloped back 10 degrees from the vertical.[2]