SOLUTION

Each suspender cable is composed of many small diameter steel wires that are wound in a helical pattern. During WJE's inspection, some cables were noted to have localized discoloration or light surface corrosion beginning between the individual cable strands. Also, near the upper ends of several cables, water dripping from the top row of clevises onto cables anchored at the two rows below caused areas of the lower cables to experience prolonged exposure to moisture. Accelerated wear of the galvanized coating in localized areas and the onset of corrosion began as a result. Spreading of the individual wires of the cables in these areas was observed at one such location. Abrasion of the galvanized coating along the length of the cables was also observed to have caused moderate surface corrosion in localized areas.

The level of corrosion did not pose a structural concern. However, since these cables serve as the primary structural support for the roof, WJE recommended a more frequent inspection cycle to establish the rate of progression of the corrosion on the cables. To avoid the expense of constructing scaffolding around the cables to facilitate access for inspections, WJE was retained to utilize industrial rope access techniques to access the tops of the masts and to inspect the lengths of the cables and their anchorages. Climbing, rappelling, and ascending were utilized to provide arms-length inspection of the cable anchorages at the tops of the masts as well as at an assortment of cables during each inspection.