Math formula for load placement

No expert but...

(25,000/45,000)41 = 22.7777777

So, 22.8' from the kingpin would be the center of the load.

Right? Wrong?

 

For the center of a 48 foot trailer that would be about right. According the math that was posted from kingpin to center of spread axle. And would only work if the weights were ideal. (split evenly )

He wants 20,000 more on the rears. The load would have to be farther back. Or the weight of the load.

And when you think about it. The trailer always gets most of the weight anyways. The axles only weigh around 9,000 while the drives weigh closer to 19,500. On my setup anyways.A perfectly balanced load around the middle of the trailer. All axles weigh the same. The trailer is still packing 10,000 more pounds over the drives.

Watching the truck gauges is all i've ever done. Trailer gauges too if available.

Good question. I'll be watching for that new math to be posted.

 

To me the honest answer would be, experience and trial and error. It's every bit as much art as it is science. You'll just have to get some loads and figure it out, every truck and trailer is a little different.

 

Tallest trailers has an awesome calculator on their website. You need to input lots of weights and measurements into it to get it accurate. In your scenario tho you forgot how much weight of the load is going to transfer to your steer so if you want 25k on the drives you need to add the transfer into that number.

 

Here is the Talbert calculator.

http://www.talbertmfg.com/custompage.asp?pg=widetemplate

 

You would need to have your empty weights to start. That load would be maxing a 6 axle rig. Center of trailer is halfway between the kingpin and the middle trailer axle.

30ft long, 70000lbs. 70000/12=5833.33. Dead center would put 35000 per axle group. So to put 45000 on the trailer axles, place it 1'9 towards the rear.

The problem that I see is the trailer used. Haven't seen a 6 axle rig with a 34 ft well.

 

Yes but you could put it on a three axle step with 38 ft down.

 

I've got a couple that regularly see 70k+ with no problems.

 

Ive never pulled one. I don't know the measurements of that trailer. Wasnt for sure if the step would give you the room to move the load. I myself was thinking 4 axle oilfield lowboy, but to max things out had to stay with 6 axles.