What was a Chicago Piano?

Answer 1

The Chicago Piano or the 1.1-inch Quads was an anti-aircraft gun used on navy ships during WW2. In 1933, the US Navy needed an automatic anti-aircraft gun that was between the machine gun and the larger dual-purpose guns. They were presented the Hudson Gun that fired a 1.1-inch shell. It was developed to fit on a mount that fired 4 guns simulataneously in order to achieve the desired firepower. There was some design problems with the mount and improvements allowed it to enter service in 1938. The Hudson 1.1-inch gun was a water-cooled gun that used a gas-set, spring operated recoil. It could fire 150 one-pound high explosive shells per minute with a muzzle velocity of 2,700 feet per second to a max range of 7,000 yards. The 1.1-inch Quad was mounted onto everything from destroyers to battleships and carriers. It was in action at Pearl Harbor but there is no record of one downing a Jap plane. Soon the 20-mm Oerlikon automatic guns were replacing the .50-caliber maching guns and the 40-mm Bofors in twin and quad mounts began to replace the Hudson 1.1-inch Quad mount. *This can also refer to the Thompson machinegun, or Tommy-gun, used by gangsters in the 1930's.