The Flying Fortress
Plexiglas is used for a number of different applications including submarine periscopes, windshields and gun turrets for airplanes. During WWII, acrylic sheets were used as bullet-resistant glazing on fight planes. They were also implemented into B-17 bombers for gun turrets later in the war. The B-17 bomber, or Flying Fortress, was a strategic bomber that was capable of sustaining heavy fire, although in early missions there was a 25% lose rate. The nose of the plane was made out of Plexiglas and was used as a turret for the front of the plane.
There are two methods used to form Plexiglas, hot bending and cold forming. The main difference between the two methods is implied in the name. Cold forming forms Plexiglas at room temperature. The curve of the bend in the Plexiglas must be a minimum of 180 times the thickness as the sheeting. Cold forming isn’t suitable for sharp bends. For hot bending, the Plexiglas needs to be head to about 290 degrees and is only bendable for a little less than a minute.
Perhaps one of the most notable Plexiglas turrets was the ball turret on the bottom of the B-17 bomber. The ball turret was a small, hollow Plexiglas sphere of death. It was designed to rotate to allow the gunner to shift positions in attempt to hit enemy planes. Gunners were cramped in these turrets and cut off from the rest of the crew. They were exposed to enemy aircraft fire and were seen has the most dangerous place to be on an airplane, although statistically it is the pilot.
After noticing the highest casualties were the bombers that broke formation, the planes started flying in a combat box formation. This allowed all B-17s could safely cover the other planes in their formation. German Luftwaffe fighters likened it to attacking a flying porcupine. It took a significant amount of bullets from German planes to down a B-17 Bomber unless hit in small, vital areas. The planes were an American symbol of power and air superiority during the war and are still remembered by many today.