Pearl Harbor Naval Shipyard, HI
UT Inspection & Repair Caisson, Drydock 4, Pearl Harbor, HI
This project required visual and UT thickness inspections of the existing caisson plating in Drydock 4 per Mil-Std-1625. The caisson was constructed in approximately 1943. Repairs were made based on the deficiencies found in the inspection.
Additional caisson repairs were also required based on previous inspections. This work included removal and replacement of exterior caisson anodes and support rings, replacement of corroded caisson ventilation intake housing, installation of support bars on the main ballast tank hatches, repair of a corroded transverse structural member located in the main ballast tank, replacement of operating shaft and supports for one discharge valve, replacement of operating shaft and supports for two trim equalizing valves, replacement of operating shaft for a flood valve, addition of new supports at operating shafts, repair of numerous pinhole leaks within the caisson, installation of a lifeline within the ballast tanks, installation of ladder cages for ladders into the main ballast tank, and suction grating re-centering on a discharge pump B.