Rusty cables could mean a $20 million repair bill
The Hale Boggs Bridge (Luling Bridge) needs new cables and the Louisiana Department of Transportation is opening the bids as early as July 2008 for contractors interested in applying to make the repairs.
Brendan Rush, public information officer for the DOTD, said despite the three structural rating the bridge received recently, it’s safe.
“If a bridge is not in good condition, we close it down,” Rush said.
“But these rating systems can be misleading and confusing and alarm people unnecessarily,” he continued.
“The Federal Highway Commission assigns ratings after we’ve conducted our maintenance inspection,” he said.
“These ratings let us know how often a bridge should be inspected.”
Rush said that anything can change or affect the score a bridge receives after an inspection.
“In 2001 the Luling Bridge received a seven, which is a good rating,” Rush said.
“Since that time, weather and old age, a natural progression, has caused the rating to drop, and we continue to make repairs to the bridge and inspect it annually,” he continued.
Rush said there is a $14 billion backlog in making structural repairs to roads and bridges all across the state.
“We need the funding to keep up our bridges and the state needs to look at new ways to address this issue,” he continued.
“But we don’t want people to think the bridge is unsafe,” he said.
Rush said other measures taken to ensure drivers are kept safe when a bridge has been determined structurally unstable are to change load size and reduce speed limits.
“When the twin span collapsed (bridge connecting New Orleans and Slidell), we made major changes,” he said.
“We made sure that the speed limit got reduced and there was a weight limit for vehicles traveling back and forth across the bridge.
Federal law mandates that bridges spanning more than 20 feet be inspected once every two years.
“The Luling Bridge gets inspected annually in some areas, because it has some structural problems that need to be checked on a more frequent basis,” Rush said.
Gill Gautreau, engineer of bridge maintenance for the DOTD has 35 years of experience, and explains the rating.
“The Luling Bridge got a three because the cables holding the bridge are bad and need to be replaced,” he said.
“What residents need to understand is that this bridge is very unique in its structure and design and it will require a certain kind of bridge repair company to change the cables,” he continued.
Gautreau said the Luling Bridge was the first major cable stay bridge in the United States.
The cables that support the bridge are deteriorating — they are rusting more rapidly than anticipated and need to be replaced.
“We don’t know how long they’ll last as they are,” he told the Herald-Guide.
Gautreau said the cables have a multi-task protection system that was good enough in 1983, but is not good for our standards today. “The bridge was designed in the late 70’s,” he said.
“It was developed after World War II,” he continued.
“Given enough time, if the cables are not replaced the bridge could collapse.”
“Repairing the cables could be very expensive,” he said.
“Replacing the cables would be smarter and that is what we are planning to do.”
Gautreau said only one company, has done this type of cable replacement, and they’re located in France.
“We had some preliminary meetings with the firm during the earlier half of this year, and they are working on cost estimates right now to do the work,” he said.
“Lane closures could be possible when we begin making these repairs, but we shouldn’t have to close the bridge down, however it’s still too early to determine that,” he continued.
The cost of replacing the cables is between $10 million and $20 million dollars.
Gautreau said this money will come from the Bridge Replacement Program, money provided by the federal government for bridge repairs.
“Once the cables are replaced, the bridge will get a much better rating,” he said.
For right now, Gautreau said, sensors will be used to detect whether or not the cable wires are ready to snap.
“There are 72 wires holding up the Luling Bridge. The Fred Hartman Bridge in Houston, TX has a similar system to measure whether or not a cable is getting ready to break, “ he said.
“And the laser method will also be used to determine a possible split in the cables.”
Gautreau said a consulting firm out of Illinois will be contracting with them to monitor the Luling Bridge.
“This bridge is so unique we’ve always had monitors on them to detect cable movement for possible deterioration.”