Following a routine state inspection that found evidence of corrosion, the Linden Avenue bridge crossing the Saw Kill Creek in Red Hook is now open only to passenger cars.
On June 21, just in time for the last day of school, signs were posted on Linden Avenue/County Route 79, warning of a lower, 3-ton weight limit on the heavily traveled bridge. That means school buses, trucks and any vehicle larger than a passenger car are banned from the crossing.
Greg Bentley, director of engineering for the county’s Department of Public Works, told The Observer that on Thurs. June 20, the state inspection revealed “a significant corrosion had taken place in the last two years,” so the county had to immediately impose a weight limit on the bridge. Before that, the bridge was not posted with any limit.
According to Bentley, his office received the news from the state engineers at the close of business on Thursday and acted quickly to inspect the bridge and post signs on Friday. “The other option was to close it, which was not desirable,” Bentley said.
Bentley went to meet with school officials on Friday, recognizing that the timing of the signs on the last day of school was less than ideal. “They’re aware of the situation and we’re aware of the impact upon them,” he said. Buses and trucks were re-routed to Routes 9 and 9G using such side roads as Rockefeller Lane to the north and Park Avenue to the south.
Bentley said the bridge was built in 1926 and is inspected bi-annually. It’s an older type of bridge called a jack arch bridge. Steel I-beams form the structure, which is then filled with concrete.
“This creates a bridge that is very strong and will last a long time,” Bentley said. “But when they deteriorate at the end of their life, they tend to do it in surprising ways, since there’s only so much of the bearing structure of the bridge that we can see [through the concrete].”
He said that for this reason, engineering analyses of these bridges tend to be conservative and “may indicate a carrying capacity that is less than the actual carrying strength of the bridge.”
Further inspections were made by consulting engineers on June 23, which confirmed the state and county’s findings, and more signs directing motorists from Linden Ave. to Routes 9 and 9G via Rockefeller Lane and Park Avenue are now in place.
Bentley estimated it would take the county two weeks to analyze the engineers’ reports and come up with a plan to either repair or replace the bridge. He thought that if a repair was possible, the county might be able to do it this summer. However, if the entire bridge needs to be replaced, he said it was “extremely unlikely that it would happen this season.”
He said the DPW is aware that the bridge is a “critical pedestrian link” for the recreation park, and that the county would factor that in, along with its proximity to Red Hook’s schools.
Based on a study done several years ago, Bentley estimated that approximately 2,500 cars cross the bridge each day.