From Wiki:
"These guns were 50 calibers long, 50 times their 16-inch (406 mm) bore diameter with barrels 66.7 ft (20.3 m) long, from chamber to muzzle. Each gun weighed about 239,000 lb (108,000 kg) without the breech, and 267,900 lb (121,500 kg) with the breech.[1] They fired projectiles weighing from 1,900 to 2,700 lb (860 to 1,220 kg) at different muzzle velocities, depending on the shell. When firing armor-piercing shells, their muzzle velocity was 2,500 feet per second (762 meters per second) with a range of up to 24 mi (39 km). At maximum range the projectile spent almost 1+1⁄2 minutes in flight. Each turret required a crew of 79 men to operate. The turrets cost US$1.4 million each, excluding the cost of the guns."