Train traffic between Anchorage and Fairbanks was disrupted and in some cases brought to a standstill Tuesday after a highway accident just south of Denali Park damaged an Alaska Railroad bridge.
A tractor-trailer hauling an excavator passed under the bridge at 8:20 a.m. about a quarter-mile south of the Denali National Park entrance. Railroad officials said the bridge rises nearly 18 feet above the highway, but that wasn’t tall enough for the excavator.
The excavator struck the steel support beams beneath the bridge, dragging across the steel, crumpling some and curling some back from the span.
The accident resulted in “compromising the integrity” of the structure, according to an Alaska Railroad statement.
“It was pretty significant force,” railroad spokesman Tim Thompson said late Tuesday afternoon, “We have crews on scene assessing the damage, what it’s going to take to do repairs. When you really get down to it, it’s about safety. We want to make sure that bridge is safe for people to travel on.”
It is a shame the website link doesn’t have a picture of the bridge and the damage done. I’m thinking it’s a regualar “overpass railroad bridge” These are normally made out of steel and concrete. I’m surprised that the tractor-trailer took out three steel support beams, gee I hope no one was hurt.
I do wonder if the birdge could of been a truss bridge as well?? Now, that would be interesting for the tractor-trailer to take support beams out of that one!
It’s nothing for the boom of an excavator to completely ruin a bridge, especially if the truck it’s on is travelling at highway speed. It’s usually the joint between the inner and outer boom that hits the bridge, and being so small (relatively) creates a significant point load on teh bridge girders. I saw a video once where they drove a truck with an excavator on it into a bridge on puropse, and not only did it bend and split the girders, but shifted the bridge off it’s bearings. And the excavator didn’t even come off the back of the truck.
Boats and houses have been known to dammage concrete highway overpasses so bad they have had to be replaced. Not clearingn an overhead structure is the #1 cause of truck accidents, they say. 18ft. is usually plenty high enough to clear any highway traffic. Sometimes equpment has been transported on a route for years without any problem. But then one day it clips something on that same rout. Road improvements (new paving raising the road highth), not loading equipment the same way, or a new or different moving equipment are usually the causes.