Driving a single axle and pulling a set of pups is legal up to 80,000 gross. Of course, with any single axle, be it tractor, pup, or gear, the weight limit is 20,000 lbs. As long as no axle weighs more than 20,000 and the gross doesn't exceed 80,000, you're good to go.
That brings us to the dark side, the local dock supervisors. I was lucky, in that, I had an in yard scale available and wasn't afraid to use it. I have taken many trailers back to the dock, which almost always resulted in a late departure. Sometimes, they would give me the old " we do it all the time without a problem" reason but they gave in when I suggested calling safety, for a decision. Usually, it took just a few late departures before the supervisor started paying attention. Bitchy wheel gets the grease comes to mind. When you have scaled enough pup sets you will know, when a set is probably good or maybe a little iffy or flat out dangerous. My personal red line was 42,000 lbs of freight somewhat equally divide between the two pups. If a set was 22,000 and 21,000 then I would pull it but, if the split, was 24000+ and the rest on the rear, we would have to talk about that one. If you are starting, from a non scale terminal, you will just have to raise hell about what you think are heavy trailers. Maybe I was just lucky and they gave in, probably not, or maybe they just got tired of hearing me bitch, probably true, either way, they gave me what I wanted. Good luck.
