ALLENTOWN, Pa. — PennDOT engineers will likely hold new conversations about the vulnerability of bridges and overpasses to fire in the wake of Sunday's Interstate 95 bridge collapse in Philadelphia.
Mike Rebert, PennDOT's deputy secretary for highway administration, told LehighValleyNews.com on Thursday that engineers don't usually design bridges with fires in mind. As a result, the steel beams used in their decks typically aren't insulated, leaving them exposed should a high-intensity fire occur. He said he wasn't aware of a bridge in Pennsylvania that took the precaution of insulating steel beams in its decks.
It's rare for crashes to create temperatures capable of threatening the structural integrity of bridges, but they're not unheard of. Rebert rattled off a number of accidents in Pennsylvania that forced road closures, including a 2013 tanker truck explosion outside Harrisburg that destroyed a section of Route 22-322 and a massive 1996 tire fire that shut down parts of I-95 in Philadelphia. Encasing steel beams in concrete could better protect them from fires, he said.
- Few, if any, bridges in Pennsylvania insulate the steel beams used in overpasses and bridges, leaving them potentially vulnerable to high-intensity fires
- The failure of steel beams in a tanker truck crash led to the Interstate 95 bridge collapse on Sunday in Philadelphia
- Crashes like that are rare, but PennDOT engineers will likely discuss if more protections are necessary to protect infrastructure from fires
"I think we'll have a discussion about it, but can we do it everywhere? Probably not," Rebert said. "We need to at least look at it and determine that if we do do it, where do we do it?"
Factors that could be worth the extra investment include bridges supporting high volumes of traffic and those frequently used by trucks, he said. Tanker truck crashes in particular can produce the high temperatures capable of warping steel, Rebert said. The Lehigh Valley has become a major freight corridor in the last decade, and several bridges along Route 22, Route 33 and Interstate 78 could meet those standards should PennDOT ever adopt them, he said.
Before being promoted in April, Rebert served as the executive director of PennDOT District 5 for 15 years. The district handles engineering work on PennDOT construction projects in a six-county area that includes the Lehigh Valley. He was a guest speaker Wednesday at the Lehigh Valley Transportation Forum at the Mack Experience Center.
He told attendees that he woke up Sunday to learn a tanker truck carrying over 8,000 gallons of fuel crashed on the Cottman Avenue exit ramp underneath I-95. The resulting inferno destabilized the steel beams supporting the overpass. The part of the bridge carrying northbound traffic collapsed, and the lanes for southbound traffic are no longer safe. Clean up crews have recovered one body from the wreckage.
"My eye hasn't stopped twitching since," Rebert said.
While the forum was underway, Gov. Josh Shapiro, Philadelphia Mayor Jim Kenney and PennDOT officials announced demolition of the I-95 bridge should be completed by Thursday. From there, road crews will backfill in Cottman Avenue and pave over it to allow the highway to reopen. Officials did not provide a timeline on when that work will be completed.
