Bill Sosko, Project Designer in our Pittsburgh Bridge Inspection Department, has inspected approximately 2000 bridges over his career. We spoke to Bill for an insider’s perspective on what happens when a bridge is inspected, from the things inspectors look for to the aspects that make him nervous. Read on to get the scoop!
What’s the most memorable LDG bridge inspection you’ve done?
The recent inspect we did of the Ambridge-Aliquippa Bridge in Ambridge, PA. The bridge has a difficult inspection access, which makes the inspection time-consuming because the equipment doesn’t fit through openings between the truss members easily. It takes a skilled operator from the rigging company.
Then there was traffic to contend with because the bridge is only two lanes. The inspection truck doesn’t fit into one lane, which can have an impact on traffic if you’re not innovative with solutions.
What do you look for in a bridge inspection?
It depends on the bridge; each one has its own characteristics, configurations, and construction materials. You get a feel for what types of deterioration to look for and where to look for it. Steel deteriorates differently than concrete, which is different from stone masonry.
What’s your favorite part of an inspection?
I like to do the floor systems underneath the bridge deck, which is what the public drives on. The deterioration generally comes from salt water from northeastern winters. It causes corrosion. You’ll see all types of deterioration through the floor system—cracks from stress, corrosion from salt, etc. Everything you’ve trained for you can find on the floor system of a bridge.
Do you ever get nervous during an inspection?
Not anymore. One thing that can make you nervous is the traffic, because that’s the one thing you really can’t do much about.
For instance, we were recently doing a state bridge in Beaver County, and I was inspecting the floor system with no idea what was happening on top of the bridge. I heard sirens, but they didn’t strike me as unusual because the bridge is near a medical center and ambulances cross it all the time. Suddenly, I realized there was more than one siren, and I thought there might have been an accident. The sirens came and went. When I came up from underneath the bridge, the rigging foreman said there was a high-speed chase that crossed the bridge at upwards of 70 mph. The suspect was hitting the cones on the bridge. Fortunately, at that point, there was no traffic coming on the single lane restriction.
What happens after an inspection?
That’s when you prepare the inspection report. There’s a lot of information that has to be organized, such as photos of the deterioration, maintenance/repair items for the client, etc. For bigger bridges, it can take as long as 40 hours to prepare the report. For smaller structures, it can take as little as 4-6 hours. It varies a lot.