Underwater Propeller Change,
USS Enterprise, CVN-65

Introduction

A waterborne propeller change on one of the Navy's largest ships- The USS Enterprise CVN-65- was completed last Spring (1983) by divers of the USS Hector AR-7 with assistance from the Mobile Diving and Salvage Unit Hawaii. Command and Logistics support were provided by COMNAVAIRPAC, Naval Sea Systems Command, and SUPSHIP San Francisco.

Enterprise's propeller weighed 34 tons and measured 21 feet in diameter. The propeller replacement while Enterprise was waterborne represented the first time the US Navy has accomplished an underwater propeller change on a ship of that size. The operation also gave the participating divers an opportunity to learn and apply special techniques, equipment, and rigging procedures. Finally, and most importantly, by conducting a sucessful waterborne propeller change, the potential delay and expense of drydocking Enterprise were avoided.

Enterprise grounded in San Francisco Bay on 21 April 1983, resulting in damage to the #1 propeller. To avoid conflicts with previously scheduled ships restricted availability, the non-availability of a nuclear certified drydock and insufficient channel depths in the approaches to existing drydocks in the area, it was decided to explore the possibility of changing the propeller in the water. On 09 May 1983 a meeting was held at the office of SUPSHIP San Francisco. Representatives from COMNAVAIRPAC, NAVSEA, Mare Island Naval Shipyard, and Long Beach Naval Shipyard met, e3valuated the results of the underwater hull survery, and decided that there was a high probability for successful waterborne replacement.

In an operation of such magnitude, it was inevitable that divers would encounter some difficulties. For example, the was delayed several days because the divers had to learn and master a new underwater cutting technique to cut the propeller nut. The use or adaptation of other equipment such as air hoists, hydraulic pancake jacks and specialized rigging techniques are further examples of the technical knowledge gained during the Enterprise propeller change.

WebMaster Bruce