Bridge Ratings and Tractors

Anyway, in Connecticut, crossing a posted bridge exceeding the weight limit "shall constitute reckless driving" which puts it right near the top of stuff you don't want on your driving record.

Fortunately, most of the bridges are in good shape and I know very few that haven't been rebuilt over the last 20 years.

Rod

So is this a dead end road or is there another way in????? ?? That makes all the difference.

They make 2 kinds of weight signs. Yellow for caution and white for law in stone. If you go over a white sign bridge and break it you bought it. The sign will also have a different weight for straight trucks and trailers if it applies to this bridge.

I live on a dead end road that is posted. Our road department says we can bring what we need to in or out but he would just like us to be advised that the bridge is not concrete. If we can cut the load a little he would be happy.
It has a yellow sign.

Now with that said a bridge will hold a lot more than its rating. You need to take into account that you may have 2 trucks on the bridge at the same time. 1 each way. This is why the log and milk trucks can get across them and not break them. You may go across this bridge for years along with all the other local traffic but one day you may also be the one poor sucker it breaks on.

I know a guy that had the same cavalier attitude as one of your respondants. One exception he was knocking these bridges out on purpose. He was always hauling this D7 on a lowbed, just as tractor was about to leave bridge he'd let the dozer blade hit the side rails so only dozer and low bed went down. He got about 4 bridges and finally he had to pay for one. One day that proceedure turned the dozer crossways. He found his dozer and low bed impounded until he posted a bond to value of bridge. Some jurisdictions may not be that lenient.

This is one of those things that you really should get the intimate details about, with the resident engineer in the munincipality and or whomever the presiding authority is.

When you think about a span, you have to realize that it does have a maximum live load, hopefully with some safety margin beyond that.

When you drive your rig over the span, each of the axles are going to impose/transfer a portion of the gross overall weight of your truck/trailer combination onto the span. Like was mentioned if it works out that none of the axles point load the span in excess of the maximum allowable load, it's possible that it may work, but I'd make sure someone gave me authorization like the engineer after doing some calculations and or whatever it takes.

I recall while in college, we used to build beams of concrete and place them in a machine that had a roller that imposed a live load to the beam, you could apply enough weight to it until failure, then analyze the results depending on what section of it failed, left, right, or middle section. The roller is kind of like an axle of a loaded truck, deflecting the beam until failure, with the exception it's just one beam not an entire structure.

Not trying to lecture here, it's an interesting subject, how things like this actually work.

Another thing to consider, the design may say one thing on paper, but what is the actual condition of the bridge,is it of modern construction or an older one? Has it been de-rated, or inspected recently to insure it's still capable of it's original design loads ? That is an important aspect of this. If it's even remotely questionable, I'd not even go near it until it was properly inspected and evaluated and the ok given.

In addition to that, because I'm such a detailed orientated pain in the behind, having worked with structural engineers closely on many projects, I'd measure the axle to axle distances, width of the axles etc. get the loaded truck and trailer weighed, and include that for submission to the engineer, requesting permission to cross the bridge as configured and or something along these lines, I'd want some sort of approval in writing. Providing this information is not all that complicated, get to a scale, measure everything, call the person up, ask if any other information is needed and send it in, let them bear the responsibility of providing a definitive response of yes or no.

Guessing, like was mentioned, it's like gambling, with the odds stacked against you.

..... ....Jim

Here in Iowa if you get caught crossing an embargoed bridge you pay a fine.

If you break the bridge you may be paying for a new bridge.

You decide.

Gary