Underwater Propeller Change,
USS Enterprise, CVN-65

New Propeller Installed

The installation of the new propeller was relatively straightforward. After arrival and visual inspection, the 34 ton, 21-foot replacement propeller was lifted from the flatbed truck and placed on the pier using the 100 ton floating crane. A lifting eye had been installed in the propeller hub. This would allow the dive team to rotate the propeller 90 degrees on its axis before lowering it into the water alongside the barge. This was accomplished by utilizing the 50-ton chain hoist. Before the propeller was lowered into the water alongside the barge, all gland ring studs and dunce cap studs were installed and torqued. The propeller and the attached 50-ton chain hoist were then lowered and secured to the barge is balance beam. The barge was then repositioned alongside the Enterprise at Frame 228 and the divers installed the O-Ring and gland ring on the shaft.

The propeller was rigged from the barge's balance beam under the ship to the aft 50-ton chain hoist in a yard and stayed arrangement. Using a yard and stay arrangement with the foreword and the aft 50-ton chain hoists, the propeller was positioned on to the shaft and advanced up the taper. A 6-ton chain fall attached to the strut assisted in advancing the propeller up the taper to within one-half inch of its final seat.

The pilgrim nut with its attached wire sling and snatch block was yard and stayed into place and screwed on to the shaft until it was hard against the propeller hub. It was pressurized to 14,000 PSI, retightened and repressurized to 16,000 PSI - thus seating the propeller home. The pilgrim nut and the 3, 50-ton chain hoists were then removed. The boss nut, already installed in its speed wrench, was yard and stayed from alongside the barge to the after propeller lifting hall fitting. It was then yard and stayed into place on the threads by fore and aft a rip hoists. The nut was advanced by wrapping and pulling wire about the nut circumference. Once into place it was tightened with the nut wrench. The lock pin hole was lined up, the pin installed and the wrench was then removed.

The dunce cap was rigged under the ship using the after grip hoist wire, it's O-ring installed and rigged into position against the propeller hub, using the forward grip hoist wire. The dunce caps stud nuts were installed, torqued to 575 foot pounds, and the cover plates were screwed back into place. The forward gland rain nuts were installed and torqued to 105 foot pounds. The propeller and dunce cap were flushed with preservative until no water was present. The screw cavities were then filled with preservative. Vent and fill plugs were installed. The dunce cap was pressurized to 25 PSI, checked for leaks, then filled with preservative and plugged. The dive team had successfully completed the propeller change on the waterborne USS Enterprise.

WebMaster Bruce