Pipe load

I have a 48’ spread and I always center the load about 3-4 feet behind the centerline of the deck FWIW. By your figures your rare weight is 34k? Seems heavy

 

I usually split the difference.

 

You dont need to split weigh a spread on The cat scales, yes as shown above the axles are slightly different, but unless youve got 39000+ on the spread, youre going to be fine, just take trailer weight and divide by 2 for individual axle

For exact weight center, though this can vary somewhat (usually about 6 inches +/-) as a rule of thumb, mark where the center of trailer axle grouping is, mark where your kingpin is, in the center of that is your weight's center. Now mark there.

For a uniform load as you stated at 40 foot, 20 foot forward lay a block, no peice should go forward of that. Tadaaa, your load is now balanced between trailer and drives. Worried about weight? Open the spread and load it 2 feet closer to the rear, now youre tail-heavy but not by nearly 9000 lbs

 

I run into this more than I like to with big loads. Pretty much have to walk in and tell the cashier how to weigh the truck. The horror in their faces when one wants to weigh 11 to 13 axles of joy.

 

For a CAT scale to do a split weights, all they have to do is press the split weight button on the main screen, then follow the instructions. If needed, they can call the number that comes up on the screen. A direct line to support.

 

Center of the load between the king pin and the center of the trailer axles and you will be good.