The speed reducer shall be a direct coupled, V-belt, or chain driven enclosed concentric type unit with a double or triple reduction ratio. The published rating of the speed reducer shall conform to all applicable AGMA standards. The reducer housing shall be constructed of corrosion resistant, ductile iron with cast internal walls for added strength. All housings and end covers shall be doweled and precision machined to assure accurate alignment for all gear sets. All gearing shall be of single helical design, and crown shaved or ground to provide an ellipsoid tooth form to eliminate tooth end bearing and assure meshing in the strongest tooth area. All gears shall be case carburized to insure a high surface durability and resilient tooth core for greater impact resistance and longer service life.