Report: Some Bridges in County Problematic

CREST HAVEN — Of the five bridges the County Bridge Commission owns and operates here, only the Ocean City-Longport Bridge is not considered “structurally deficient” and “functionally obsolete,” according to a report issued by Dale Foster, county engineer, as part of Gov. Jon Corzine’s order to inventory the status of New Jersey’s bridges and ensure their safety in the wake of the Minneapolis I-35W bridge collapse.
The commission owns and operates the Ocean City-Longport Bridge, Corson’s Inlet Bridge, Townsend’s Inlet Bridge, Grassy Sound Bridge and the Middle Thorofare Bridge – all toll bridges.
None of the bridges has a structure similar to the Minneapolis bridge which collapsed on Aug. 1, Foster told the commission.
The terms “structurally deficient” under the category of “sufficiency rating,” and “functionally obsolete” can be misleading out of context, Foster told commissioners Aug. 9.
Federal Highway standards require a load limit of 40 tons on all bridges. Anything that is designed for less is considered functionally obsolete. All the commission bridges were originally built with 17.5 ton load limits. All of them now have a load limit of 15 tons, except for the Ocean City-Longport Bridge, rebuilt and in operation since 2002. It has no load limit posting.
“If these (four) bridges were built brand new, they would still be functionally obsolete,” Steven O’Connor, county administrator, told the Herald this week.
“These (four) bridges were designed for passenger cars, not truck loads,” Foster told the Commission.
According to an Aug. 9 statewide Department of Transportation report issued to the governor, “structurally deficient” are “those bridges whose deck, superstructure and/or substructure are deteriorated; however, this does not mean that these bridges are unsafe to travel on.”
Besides the Bridge Commission bridges there are 22 county bridges and the Beesley’s Point Bridge which is privately owned. Of these, the Marshallville Road Bridge is deficient and closed. Beesley’s Point Bridge is also deficient and closed, pending rehabilitation.
The sufficiency rating is a guide by the federal government to identify bridges for priority in receiving federal funds, O’Connor said, so any bridge with a rating of 50 or less gets top priority for replacement; under 80 for repair funds.
A large component of the sufficiency rating is derived from the structural adequacy and safety assessment, comprised of a combination of the live load, and the lower of two condition appraisals: the superstructure and the substructure of the bridge.
The sufficiency rating for the Ocean-City Longport Bridge is 87.4; Corson’s Inlet Bridge is 12.4; Townsend’s Inlet Bridge is 2.0; Grassy Sound Bridge is 2.0; and Middle Thorofare Bridge is 7.0. All four of the lower county Bridge Commission bridges would have priority for replacement under this designation, Foster said.
Foster reported the Corson’s Inlet Bridge was the subject of emergency repairs due to deteriorated condition of the steel stringers and bascule girders, part of the mechanism that draws the bridge. The emergency repairs restored the bridge from 3 tons to a 15-ton load posting. The Townsend’s Inlet Bridge and the Grassy Sound Bridges are currently under contract for repairs with Bergmann Associates and PB Americas, Inc. for similar problems relating to extensive steel corrosion in the bascule span – the metal grate roadway that raises and lowers – and/or steel stringers, spalling or chipping, on the concrete piles, bearings and bearing plates issues, fender system and/or severe scaling of concrete, or flaking, in some piers.
“If you would lose a stringer in the approach road all you’d have was a dip in the road, not a failure,” Foster told commissioners.
Of the four, the Middle Thorofare Bridge is currently in the design phase for replacement, while all four deficient bridges will eventually be replaced as federal funds become available, O’Connor said. They can only be replaced one at a time.
“There’s just not enough money to replace them all at once,” he said.
The priority now for the bridge commission is the Middle Thorofare Bridge, a draw bridge, located between Wildwood Crest and Lower Township. Commercial fishing vessels use the waterway here constantly. The bridge has become obsolete for the commercial fishing industry, O’Connor explained, as there are vessels which simply cannot fit through the draw.
There are two designs being considered for the Middle Thorofare Bridge – both of which would be fixed-span bridges, similar to the Ocean City-Longport Bridge: a cable stay, and a concrete cemented bridge, with the two designs being comparable in cost. After public input at hearings held several years ago, the cable stay was determined to be the preferred design for its attractiveness. One issue still being resolved, however, is the impact the cable stay design would have on flight patterns of birds. The New Jersey Audubon Society is in the second year of a two-year study of bird flight patterns as part of an agreement with the county to determine any negative impact the design might have on bird migration and flight patterns.
“We recognize especially in this area that birding is very important, and we agreed that if they did a scientific study we would go along with their finding,” O’Connor said.
Last week, the bridge commission authorized two emergency appropriations of $15,000 each to replace two electronic gates on the Middle Thorofare Bridge after one failed.
Last year, O’Connor said, the county bonded $10 million for maintenance and repairs to commission bridges.
“Of that $10 million,” he said, “about $4 million is earmarked for bascule span replacements … then structural repairs — $3-4 million for all four, and another $2 million is set aside to paint the underdeck of the Corson’s Inlet Bridge,” he said.
Painting is a huge cost factor in maintaining the commission’s bridges, because of the corrosive effects of salt water and sea air. Keeping the bridges painted protects the structural integrity of the steel. It costs $2-2.5 million to paint each bridge, O’Connor said.
“You can only get six to eight years out of a paint job before you have to do it again.”
The Townsend’s Inlet, Grassy Sound and Middle Thorofare Bridges were built in 1938, Foster said. The Corson’s Inlet Bridge was built in 1948. Steel was used when these bridges were built in the 1930s and 40s. The connections were riveted, not welded; riveted connections do not normally cause cracks in the steel, whereas welded connections can, Foster said. Nowadays, concrete is used, a much more appropriate material in a marine environment. The steel requires constant maintenance and repainting. The time frame from conception to replacement of a bridge can take a decade or more, he said. The newest of the five commission bridges is the Ocean City-Longport Bridge, which was finished in 2002. Planning for that replacement began in 1992.
The county anticipates bonding for another $12 million in 2009, O’Connor told the Herald, to go back and continue to do structural repairs and repaint the underdecks.
“All are beyond their life expectancy,” he said. “They were all built with federal money. The only thing the commission can do is continue to rehabilitate them and maintain their safety.”