Main Reduction (Bull) Gear Segment

Main Reduction (Bull) Gear Segment. . , This segment of the main reduction gear was donated to the N/S Savannah Association in 2009 by the Southern Scrap Company of New Orleans, Louisiana. It weighs about 37,500 lbs, or just about half of the weight of the complete gear. Notice that the hub section is solid, it contains the cut-off section of the stub shaft that connected the gear to the propeller shafting. Notice also the key and slot that fixes the gear to the shaft, and prevents the gear from rotating against the shaft., In 1981, a full decade after Savannah last sailed under her own power, this gear was removed to replace a damaged gear in the naval tanker American Explorer. Although documentary evidence shows that the gear was removed from Savannah, and Savannah's gear boxes inside the engine room are empty, mystery surrounds the evolution. Visitors to the engine room will find no obvious path by which the gear was removed. And there are no marks on the outside of the hull to show where an access hole was cut to allow the gear to be rigged out of the ship. So how did it happen? If you know, or if you know someone who knows (or better, has pictures!), please contact the Association., After receiving a second lease on life from Savannah's gear set, American Explorer enjoyed another long decade of government service before finally being retired to the Maritime Administration's Beaumont (Texas) Reserve Fleet. The ship was sold for scrap in 2008, and during that process this gear segment was acquired by the Association. No mystery surrounded the removal in 2009; the entire engine room was cut away form around the gear before it was lifted out of the hulk of the ship!, In a quirk of fate, the American Explorer almost, became America's second nuclear-powered merchant ship. Construction was suspended after the ship was launched while studies were made to install a compact merchant ship nuclear reactor (a General Electric Model 630-A). The plans were eventually cancelled, and the Explorer was completed to its original conventional design., [Caption:] , The images are construction photographs of the gear and the complete propulsion unit. They were taken at the plant of the De Laval Steam Turbine Company. The lower picture shows the bull gear with the stub shaft showing on the right. The gear was 176.6" in diameter, 48 inches across the gear face, and there were 583 gear originally. A small segment of the gear face appears at the bottom of the propulsion unit.