Under the direction of the Naval Sea Systems Command, Supervisor of Salvage and Diving (SUPSALV), Phoenix International Holdings, Inc. (Phoenix) successfully executed a complex underwater operation: dry chamber propeller shaft flange inspections on the USS Dwight D. Eisenhower (CVN-69). The project took place at both Naval Station Norfolk and Norfolk Naval Shipyard (NNSY) in Portsmouth, Virginia.
Mobilizing on September 27, 2024, Phoenix showcased its innovation in Underwater Ship Husbandry through the use of highly trained personnel and specialized equipment. After the removal of fairing plates and fairwaters from all four shafts, divers welded rigging pad eyes onto the ship’s hull to facilitate the installation of custom-designed stern tube cofferdams. These cofferdams-measuring up to 13 feet long, 12.5 feet wide, and 11 feet tall, and weighing as much as 8,000 lbs.-were engineered by Phoenix to form a dry seal while allowing shaft rotation during the flange inspections.
In addition to the stern tube cofferdams, interchangeable intermediate strut habitat cofferdams were also deployed. Divers installed the cofferdams over the Rotating Coupling Covers (RCCs), which were then drained to create a dry working environment. RCCS were removed and recovered to the pier for refurbishment by NNSY personnel…