Am I bridged to haul 80k lbs ??

What's the wheelbase on your truck, and where is your fifth wheel set at? Is it fixed or can you slide it?

 

Measure from the center of your front drive axle. Or drop if you got one. To the center of your rear most axle. Then google federal bridge weights.

https://www.ok.gov/ohpcmve/documents/Federal_Bridge_Gross_Weight_Formula.pdf

Then look at your state chart. The eastern states seem to have different bridges then us on the west coast.

4 axle dump trucks hauling around 78 where as we can only haul 56.

At one point I drove an end dump. No idea how long that trailer was but bridge wise it was only good for 78.

 

Should go like this, triple trailer axles is good for 17000 X 3 51,000, tandems on the tractor is another 34,000 and to be safe the tractors steer axle 12,000. Technically you should be able to gross 97,000 with the correct permit.

Steer could go as high as 20 K depending on suspension and tire ratings.

 

That's not how it works.

Federal bridge formula allows for 34K on 3 axles if less than 8' between 1st & 3rd, 42K if 8-9', and gradually increases on up to 60K in 32'. So what's the axle spacing on the trailer?

Now, your drives are likely 2 axles and 8' or less spacing, so you get 34K there.

Your steer axle is good for 20K or whatever the lowest rated component happens to be (tires, suspension, axle, etc...)...most likely 12K or so.

Once you figure out how much you can haul on each axle group, go to the next step and expand the axle groups. You'll have a 3-axle group consisting of the steer and 2 drives...and a 5-axle group with your drives and trailer.

What's the distance from the steer axle hub to the hub on the rear drive axle? With a 250" WB tractor, that'll be around 23'...which is good for 53K (34k + 19k IF your steer is rated that high).

What's the distance from the hub on the front drive axle back to the rear-most trailer axle? If it's at least 32', you're good for 68K...which would allow you to run 12/34/34. If it is LESS than 32', the only way to run 80K legally is to move more weight onto your steers to keep the rear 5 axles within the allowed weight limit.

A 6-axle truck only has to be 43' from the steer axle hub to the rear-most trailer axle hub in order to have an 80k gross weight...and with a 250" WB tractor, that won't be a problem.

 

Forgot to mention 60 has to be a non divisible load and I'm sure it would have to be a full axle. Not just a drop axle.

My 3 axles on truck and trailer only allow 43,500 per set.