The bull gear is the largest movable (rotating) piece of the ship’s steam turbine drive train except for the propeller. It is mounted between the aft end of the turbines and the propeller shaft/thrust bearing and served as a reduction gear reducing the shaft speed to a nominal 108 RPM. This precision manufactured bull gear has a 13.5 foot diameter and a 34 inch face and weighs in at 66,000 pounds. At 108 RPM, the gear face on the bull gear was traveling at a speed of about 55 miles per hour.