The Navy Shaft Revolution Indicator System, created by the Electric Tachometer Corporation in December 1942, is a highly sought-after collector’s item due to its historical significance and technical sophistication. It was critical for the US Navy during WWII to monitor and maintain the speed of ships’ propeller shafts. The system comprised a tachometer generator, transmitter, and indicating unit, with the generator attached to the ship’s propeller shaft. The generator produced an electrical signal corresponding to the shaft’s rotational speed, which was amplified by the transmitter and displayed in RPM by the indicating unit. Its accuracy and reliability made it a crucial component in modern naval operations. Some systems are still in use today, over 80 years later, which attests to its durability and precision engineering. As a collector’s item, it holds practical and historical value, making it a fascinating addition to any collection of military or technological artifacts.
Glass Diameter: 8 1/2″
Weight: 50.5 lbs.