Inspection findings not a threat to structural integrity, DOT engineer says
The French company that installed the Arthur Ravenel Jr. Bridge's 128 cables found the equivalent of leaky shock absorbers during a recent in-depth inspection; but the leaks were minor, and overall the cables are holding up well, a top state bridge engineer said.
Inspectors with Freyssinet Group spent a month late last year checking the harp-like cable system and opening "shark fins," the white tubes that connect the cables to the bridge deck.
These shark fins enclose hydraulic systems that help dampen side-to-side movement on the bridge road deck. Inspectors found leaks in two shark fins and fixed them on the spot, said Lee Floyd, state bridge maintenance engineer for the Department of Transportation.
Floyd said the leaks weren't a threat to the bridge's structural integrity but that it's important to keep the dampening systems in sound shape. On windy and rainy days, rivulets of water can flow down the cables and make the them vibrate in a way that makes the deck move back and forth. "You wouldn't want to drive a car with bad shock absorbers," Floyd said.
The month-long cable inspection cost $275,000.
With the $637 million bridge's third birthday approaching this summer, the only major construction defect found so far involves the giant rubber bumpers that hold the bridge deck in place between the two diamond towers.
The rubber is cracking, and crews are expected to replace them this spring, Floyd said. That work is covered under the bridge's warranty. "Overall everything seems to be working fine," he said.