WASHINGTON – Residents of Denton, Md., said a state inspection team assured them in February 1976 that the bridge that carried them to schools and jobs was safe. One month later, the bridge collapsed as a car drove over it.
“All 27 school buses and a funeral procession had gone over before us,” said Janet K. Hutson, whose car teetered on the bridge’s edge as it collapsed. “It broke right underneath the car.”
Hutson’s car did not fall into the Choptank River. She and her companion escaped serious injury.
Bridges don’t collapse often. Maryland State Highway Administration officials said there has been only one other collapse in the state in the past 20 years.
The program that prevents those collapses is, ironically, based on them.
Maryland’s bridge inspection program “has basically been evolving through failures,” said Joseph Miller, chief of the SHA bridge inspection division.
It is not unlike the nation’s bridge inspection program, said Charles Chambers, chief of bridge management at the Federal Highway Administration. The FHA in 1971 implemented bridge inspection standards following a December 1967 collapse of the Silver Bridge connecting Ohio and West Virginia.
Its collapse killed 46 people.
“We implemented a very aggressive program that requires bridge owners to inspect their bridges every two years. We’ve made gains in equipment, design and the whole gamut of the bridge program,” Chambers said.
The FHA takes corrective measures when necessary, Chambers said, but “the program evolves as anything else. You learn as you go.”
The Denton bridge was a learning experience for Maryland. Its deficiencies couldn’t be picked up on “normal, routine inspection,” which in the 1970s included eyeballing the structure and banging it with a hammer, Miller said.
He did not dispute residents’ claims that they warned state officials of safety concerns, but said he couldn’t confirm them. He said the state no longer has records dating back to the original structure.
After the collapse, Miller said, inspectors determined from the wreckage that the bridge’s timber pilings had rotted from the inside out.
Now, bridge inspectors armed with drills test for deterioration. They also examine core samples of the bridges, Miller said.
Denton residents said the state should have listened to what they were saying. “It had been obvious to the people around it for a long time that it wasn’t a safe bridge, but the state came around and said it was,” said Denton town clerk Mary Turkington, on the job 25 years.
“A lot of us had been predicting this would happen. We saw the signs,” said Hutson, a retired school teacher from Denton.
Even more recently, the signs of trouble have been there, but inspectors have missed them.
An August 1988 collapse of a 275-foot-long section of the state Route 675 Bridge connecting Somerset County with Pocomoke City followed the gradual deterioration of underwater supports, the National Transportation Safety Board concluded.
State bridge inspectors had noted in 1982 that the pilings were eight inches around, Miller said.
However, he said, no one made the connection that they should have been 12 inches.
The NTSB determined the SHA gave early warning signs an “inadequate response,” a federal statement shows.
Fortunately, no one was hurt.
Inspectors now report any piling with a circumference of less than 12 inches to Miller at the SHA, he said.
“They pay me to have some foresight,” Miller said.
Chambers said this foresight, combined with hindsight, has made the FHA’s program the best in the world.
“We have very few collapses in the U.S. due to structural failures. The majority are the result of some outside force, like a ship impact or a flood,” he said.
Maryland’s recent bridge collapses haven’t been fatal. Other states haven’t been as lucky.
For example, Tennessee’s Hatchie River Bridge collapse in 1989 killed eight people, the FHA said, after bedding materials were eroded by water.
But bridge collapses don’t always leave sadness in their wake.
Turkington recalled the rebuilding in Denton as a happy time.
“Building a bridge was a big thing in our little town. We all walked down to watch,” she said. -30-