By: Gavin Jenkins
I have a border collie-mix named Bob, and he loves creeks.
He goes nuts when he sees one. He sprints into the water and clubs the surface with one of his front paws, then barks and bites the splashes he makes.
I laugh every time I see Bob stomping through a creek. I have so many videos of him doing this on my phone that I’m running out of storage space.
We live in the East End of Pittsburgh, and Fern Hollow Creek is one of his favorite spots. We often jog into Frick Park’s ravine on the Tranquil Trail until we reach the Hot Dog Dam, an off-leash area enclosed by fence and logs, under the Fern Hollow Bridge.
When I learned that Forbes Avenue’s Fern Hollow Bridge had collapsed around 6:45 a.m. on Jan. 28, I was hit with a wave of emotions: shock that it happened (this national news story occurred less than a mile from my apartment), relief that no one died, then shock again (this time for the fact that President Biden was already scheduled to come to Pittsburgh to talk about infrastructure), followed by anger—rage, really—that there were no imminent rehabilitation plans set for the bridge.
Finally, shock a third time because I couldn’t believe—and am still having trouble comprehending—how 10 people were hurt, but no one died.
The state of America’s infrastructure is a public health crisis. Not too many people frame it like that, but if the bridge had held up a little longer, more motorists would have been on it, and if Pittsburgh Public Schools hadn’t been on a two-hour snow delay, there might have been a school bus crossing it. We got lucky—incredibly and miraculously lucky.
Here’s a less-obvious statement: Maybe the microclimate under the bridge was one of the many factors that played a role in its deterioration. Kent Harries, a professor of civil and environmental engineering at the University of Pittsburgh, raised this possibility when I spoke to him.
He made good points: The 497-ft bridge stretched over a ravine that runs north to south, and the prevailing wind in Pittsburgh is out of the west.
“You would get inversions in the ravine, and it would kind of trap that moist air down there,” said Harries, who also frequents Frick Park. “That’s one of the reasons why we see probably more deterioration than we would expect on a 50-year-old structure.”
The Hot Dog Dam was so popular because the air under the bridge was cooler than anywhere else on the Tranquil Trail.
On hot summer days, in the shade of the bridge and the surrounding trees, I would sit on a bench and watch Bob run through the creek, maneuvering around rocks and fallen branches as other dogs chased him as if he was Han Solo escaping imperial starfighters in the Millennium Falcon. The other dog owners and I would talk and laugh.
There were probably several factors in the bridge’s collapse, but there’s no denying Harries’ points.
The Fern Hollow Bridge had a K-frame so people would have as much space as possible to enjoy the woods below. The next bridge over the ravine likely won’t do this, which means the Hot Dog Dam might not return.
Though it makes me sad, it’s for the best. Besides, Bob and I have other creeks.
About The Author: Jenkins is managing editor of Roads & Bridges.
