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Dry Dock #4 Repairs


Project Name: Dry Dock #4 Repairs
Location: Pearl Harbor, Hawaii
Contract Number: N62742-98-C-1329
This contract performed two objectives in Pearl Harbor Naval Shipyard's Dry dock No. 4. The first phase of the work restored the exterior seating surface of the outer caisson seat. This primarily involved the use of divers to remove and replace deteriorated concrete and reinforcement and the seating plates. There was some over-water work for the upper portions of the seat. The second and larger phase of work involved removal and replacement of deteriorated concrete in the upper 20-ft of dry-dock wall around the entire dock perimeter (approx. 2400-lf). Ninety percent of the work was performed from man-lifts approximately 35-ft off the dock floor. Both of these jobs involved repairs to waterfront infrastructure, heavy lifting for placement of reinforcement, concrete, and form work, use of mobile cranes and boom trucks involved in engineered and critical lifts, over and underwater inspection and repair work, over and underwater concrete placement. Both projects required very close coordination and operational flexibility with ship and docking operations. Both projects involved intimate knowledge of waterfront operations and repairs. Both projects involved the use of high and low-pressure grout injection procedures. Both projects involved the use of high-pressure hydro-blasting methods to remove deteriorated coatings, scale, and concrete and associated containment and environmentally compliant processing of water and residues. All concrete was delivered dry, additives and water were added at the site which required a high degree of quality control oversight. Both projects required full time professional engineer services for the quality control management. There were four unscheduled dockings, which along with increased security requirements due to terrorism led to several major schedule changes that were worked out to the benefit of all parties. Additionally, about half of the work was performed while Navy ships were in the dock. This required very close coordination and control of the repair work and materials management. Several change orders were required due to the differing conditions encountered once the deteriorated concrete was removed. Concrete and reinforcement removal and placement techniques had to be adjusted on a regular basis to account for the conditions. On a recurring basis, Triton had to re-plan the work to accommodate other contractors working in the dock. Triton's flexible management team and close customer rapport were able to accommodate the challenges. In most cases of changed conditions, Triton provided suggested solution that was eventually implemented after review by the Navy's architect/engineer firm.