The 633' (190m) Greek bulk carrier Sea Trident made a three-week dockside stop in the Portland Shipyard for the replacement of most of the frames in two holds. Substantial deterioration, caused by corrosion, was detected by an ABS inspector after the ship had discharged cargo in Los Angeles. The ship's owners, Marine Managers Ltd of Piraeus, Greece, selected Cascade General to make the necessary repairs, and the ship detoured north to the Columbia River in June.
The project required that three levels of staging be erected to give the ship fitters safe access to the 50'-high sides of the hold. The old frames were removed in an alternating pattern to maintain hull shape. The curved frame shapes in the forward sections were lofted onto plywood templates before removal to ensure an accurate fit.
Replacement frames were cut from 5/8" plate and hoisted into place using temporary lifting eyes welded to the side-deck beams. Many port and starboard structural brackets were also replaced at the bulkheads, and covered with new shed plates. Over 100,000 lbs of steel was replaced and inspected by the ABS representative in Portland. Cascade General completed the repairs on schedule in two weeks, using approximately 120 men per day in three shifts.