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.