Washington state has seven other highway bridges with clearances as low as the Interstate 5 Skagit River bridge, where an overheight load destroyed one of four spans last week.
That fact suggests that without tougher oversight of cross-state hauling, the same kind of accident could happen again.
These seven bridges measure 14 feet 6 inches or less at their lowest overhead clearance. They are “fracture-critical,” meaning a single broken beam could cause collapse.
They were built from 1927 to 1949 except for a short bridge at the Tacoma ferry terminal, built in 1994. Yet another old and low-clearance bridge, over Ebey Slough on Highway 529 near Marysville, is being replaced with a new crossing this spring.
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These are by no means the only bridges that can get hit.
According to the state Department of Transportation, there were 24 known hits on its bridges last year, 17 in 2011, and 14 in 2010.
A Whatcom County bridge near Ferndale was closed and repaired last year when an oversize excavator on a trailer hit five beams.
Washington state allows haulers to obtain oversize-load permits online, unless the load is 16 feet or taller.
The load that struck the Skagit bridge was estimated at 15 feet 9 inches in its state permit to Mullen Trucking of Alberta, which was taking an empty case for a giant drill south to Vancouver, Wash.
The Skagit bridge also was hit northbound last year, prompting a special inspection.
Besides the eight very low-clearance bridges, 52 more bridges are between 14 feet 6 inches and 15 feet 6 inches at their lowest point — so conceivably they could have been hit by that drill case.
When the load struck the Skagit River bridge, it sent one of the spans plummeting to the water, along with two vehicles. The three people inside the vehicles weren’t seriously injured, but the bridge will be closed for weeks while a temporary fix is installed.
To clear the bridge, driver William Scott would have needed to move into the left lane, with a clearance of 17½ feet to 18 feet. The right lane measures only 15 feet 6 inches at the white fog line.
“There are hundreds of oversize permits sold per day,” said Jim Tutton, vice president of the Washington Trucking Association, so overheight trucks shifting lanes would not be unusual.
But Scott told investigators he was passed by another truck on the bridge, which would have prevented him from moving over. He also said he heard no warning from the pilot car in front of him, according to Deborah Hersman, chairwoman of the National Transportation Safety Board. The NTSB expects to interview the pilot-car driver Wednesday.
By state law, the pilot car must have a pole 3 to 6 inches taller than the load, to detect possible dangers.
The federal investigation is pointing up some potential gaps in state regulations:
• There is no state requirement to post bridge clearances unless they are 14 feet 4 inches or less, and this bridge wasn’t posted, said Hersman. Truckers can find clearance information for all bridges on a state website.
• Washington has no requirement for the truck to use a pilot car in the rear, which might have deterred passing what was both a high and a wide load.
Devices are available to reduce risks of an overhead hit; light beams can trigger an alarm if a tall load breaks the beam.
The Mullen Trucking load did trip such an overheight warning at or near a weigh station, but that “was no cause for alarm” since the truck was labeled overheight, said State Patrol spokesman Bob Calkins. “The company has a decent safety record; they come through that port of entry regularly,” he said.
Jerry Ely, a Skagit Valley trucker who has been urging NTSB personnel to focus on the pilot car, said, “They [DOT] need to start making new laws and cleaning up their act in this state.”
Harvey Coffman, state bridge-preservation engineer, said that as of Monday he hadn’t yet looked into any possible reforms because he is working full time on designing the replacement span so traffic can resume.
Truckers can self-apply for a permit online, for $10 in the case of last week’s drill load.
“Last year we issued 135,000 permits. Right there, that gives you the value of truck freight that comes through the state,” said Lars Erickson, DOT spokesman in Olympia.
The State Patrol’s commercial-vehicle enforcement unit last year issued 251 citations or warnings statewide for loads that either lacked or violated an overheight permit, said Lt. Dennis Bosman.
Tutton, from the truckers group, said: “Everybody involved in the permit process, from the truckers, the pilot-car drivers, the companies and the people that issue permits for the DOT, need to really take explicit care in identifying the size of the load, so they know exactly what happens.”
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