By Jeremy B. White
It’s perfectly safe to traverse the Williamsburg bridge by car, bike or subway. This hasn’t always been the case.
A video clip from the TLC show “Understanding: Bridge Infrastructure” illustrates the dire state of the Williamsburg bridge in the late 1980’s. Ominous music plays over shots of decaying supports under the bridge, twisted metal girders, and a hole with sunlight streaming through. A man in a hardhat cautions that “this is what can happen when you turn your back on a bridge” and adds that “mere bandages” are preventing the bridge from total collapse.
That man is Sam Schwartz, who was the chief engineer for the New York City Department of Transportation from 1986-1990 and oversaw massive repairs to the Williamsburg Bridge that included closing the bridge for traffic in the summer of 1988. The city had not conducted a full inspection of the bridge until 1979, and ultimately launched a $800 million, 15-year rehabilitation that was split into eight different contracted phases.
As a result of the massive project, the bridge is in much better shape — perhaps the best of any bridge in the city, according to Denise Richardson, managing director of the General Contractors Association, whose members frequently do work on the bridge. She said the city has made a commitment to funding regular maintenance, which reverses a pattern of neglect that stretched from World War II to the bridge crisis of the 1980’s.
“We didn’t make the kind of investment in infrastructure maintenance and upgrading that we should have and we continue to pay for that,” Richardson said. “We’ve put ourselves in a situation where we’re in a state of constant catch-up.”
The state requires inspections of bridges every two years, but the Williamsburg Bridge is on a constant regimen. This includes painting “splash zones” that are susceptible to corrosion from water and salt carried by cars; cleaning the drainage system; maintaining the bearing plates that slide back and forth as the bridge expands and contracts with the weather; and working on the rocker arms that allow the structure to sway like a huge rubber band.
“Although it’s imperceptible to the naked eye if you stood in the middle of the bridge and looked at the horizon as the train passed, you would see yourself drop several feet,” Schwartz said.
The Williamsburg Bridge is a partial suspension bridge, which means that some of it hangs from cables and some of it is supported by towers underneath the bridge. Each cable is composed of a bundle of 7,696 steel wires, but unlike the cables girding the Manhattan and Brooklyn bridges, the Williamsburg bridge cables lack a protective zinc coating. Raymond Betti, a professor of engineering at Columbia University who has extensively studied the effects of cable corrosion, said this poses a problem.
“They are subjected to an aggressive environment like the Manhattan Bridge or the Brooklyn Bridge, but they do not have this extra protection,” Betti said. “That is part of why in the 1980’s that bridge was scheduled for replacement.”
Replacing the cables or re-enforcing them with zinc would be prohibitively expensive, Betti said, so engineers instead sheath them with protective coatings like linseed oil and fish oil. The question of shielding the cables from the elements came up when Schwartz led a comprehensive inspection of the bridge in 1987, but he said the cables were in good shape.
“Our projection at that time was the bridge should make it to the 23rd century,” he said.