Getting axles to scale

Think about who has done most of the training over the last few decades. Then add in the ridiculously poor understanding of anything related to even the simplest physics in our culture.

Most drivers only know what the reweigh ticket tells them, they have zero understanding of how repositioning the 5th wheel or tandem moves weight. How many times have you heard "Slide tandem forward to take weight off the drives?" It does, but the reality is that it takes weight of the 5th wheel, and that distinction can be important depending on where the 5th wheel is set.
It's analogous to memorizing the multiplication tables or any other learning by rote: one can learn the answers, but any answer not memorized is totally beyond their grasp, as there is no conceptual knowledge.

 

I’m still hung up on the definition. Do you get 20k on a single axle with adequate spacing, or do you get 40k on a tandem? It can’t be both.

 

Anything over 10' allows 20k per axle {the Federal single axle maximum) in the Federal Bridge Formula.

A tandem is defined as 2 axles more than 40" apart, but not more than 96".

 

So what’s the definition of a single axle. Here it’s whether it is indeed a single axle or an axle of an equalizing group. They’re different things and get different weights. We have way more axle configurations to sort out so it’s specific about that.

 

A single axle is one or more axles whose centerlines are 40" or less apart.

There's no specification in the bridge formula about equalization. Once the spacing is greater than 8', all that matters is that bridge formula is met. Don't know if any are still around, but I've pulled 10'1" spread chassis for ISO containers that were spring ride with ridiculously long equalizer beams, but here they were still considered 2 single axles. Those things would rattle filings loose!

 

Any spring ride spread is harsh, and a trailer suspension makes a #### of a racket. I had a 72” spring tandem with a lift at 9’ that I hauled boards on. The long empty cycles steady beat the springs off the forward axle of the tandem.