Norfolk Ship Support Activity Performs CPP Hub Replacement on USS Taylor
Norfolk Ship Support Activity (NSSA) provided technical support to Naval Sea Systems Command Under Water Ship Husbandry (NAVSEA 00C5) during the successful replacement of the Controllable Pitch Propeller (CPP) Hub aboard USS Taylor (FFG 50) in Souda Bay, Greece, Apr. 30.
Taylor suffered significant damage to its propeller blades while underway in the Black Sea, Feb. 12. Repairs to this portion of the ship are typically performed in dry dock, but an in-water hub change was performed to assist the ship in meeting its mission.
“NSSA RMC Quality Assurance (QA) Department dispatched Non-Destructive Testing (NDT) technicians overseas to perform an NDT examination of the Main Reduction Gear, to assess its capabilities after the sustaining damages,” said NSSA Hydraulics and Ship’s Controls Branch Head Richard Krewinghaus.
Inspections of the CPP system by NSSA’s Hydraulics and Ship’s Controls Branch in conjunction with NSSA’s QA Department and Steam and Main Propulsion Branch, indicated that the damage was isolated to the CPP hub and propeller blades.
“Underwater replacement of the hub created several unforeseen challenges, which our guys had to overcome on the fly. It was a tremendous learning experience,” said Krewinghaus.
NSSA, working with NAVSEA and the original equipment manufacturer, were given guidance during removal of the damaged hub and installation of the replacement hub.
NSSA’s dive locker also provided assistance, logging 221 dives (equating to more than 41,000 minutes of bottom time assessments and repairs).
“NAVSEA provided our team with guidance and procedures on the hub change out via their engineering technicians and we performed the work as quickly as we could,” said NSSA Master Diver Kelly Polk. “We went out there to solve a problem, got in the middle of the job and we were able to complete it. This repair hopefully set the standard for completing waterborne hub repairs.”
To aid in a quicker repair, assets were removed from a decommissioned FFG and transported to NSSA headquarters in Norfolk where they were disassembled, repaired, cleaned and packed for shipping.
“Within one hour of the valves’ arrival in Souda Bay, they were installed and the system was adjusted and operating properly. This allowed the pier side portion of testing to be completed that night and the ship was then prepared for underway testing,” said Krewinghaus.
Taylor made all required preparations to get underway in parallel with the repair effort. Underway testing included a full power run with a hull vibration survey, and an emergency crash back – all of which the ship successfully completed – thereby ensuring she was fully capable of resuming her mission in support of the U.S. 6th Fleet.
Press Release, May 6, 2014; Image: US Navy