Aiming the Big Guns

When the USS New Jersey (BB-62) was designed in the late 1930's, warship guns were still aimed by visual spotting, with an observer watching where an initial broadside landed and correcting the aim for the next shells. By the time the USS New Jersey (BB-62) was commissioned in 1943, U.S. Navy gunnery radar allowed more accurate shooting, so its gunfire control system used both visual and radar data to aim the guns. Information including a target's speed, course, distance, position relative to the USS New Jersey (BB-62), and the fall of shot from earlier broadsides was fed into the Mark 1 Able Main Battery Computer. This analog computer combined that information with ballistics data including the curvature and rotational spin of the Earth, wind speed, gunpowder temperature, and the USS New Jersey's (BB-62) own course and speed to produce a firing solution. The Mark 1 Able Computer was a technological masterpiece of its time and a main reason U.S. naval gunfire was the most accurate in the world by the middle of World War II, and it remained in use throughout the USS New Jersey's (BB-62) 48 years of service.

Camden, New Jersey · United States