The Scale Ticket That Fits Gross But Not the Drives
At a scale on the Richardson Highway the ticket reads: steer 11,600 lb, drive tandem 34,900 lb, trailer tandem 32,400 lb, gross 78,900 lb. Ratings: steer axle 12,000; each drive and trailer axle 20,000; each tandem group 34,000; gross 80,000. The trailer tandems sit in the middle of their track and can slide 36 inches either way. The fifth wheel can move 6 inches. Your load, 44,000 lb of stacked steel plate, sits against the trailer's front wall and cannot be repositioned at this stop. The next scale is 210 miles ahead and the receiver closes in 5 hours.
1. Which axles are legal, which are not, and which adjustment moves weight in the right direction? Explain the mechanism rather than just naming a fix.
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Legal: gross 78,900 (under 80,000), steer 11,600 (400 lb of room), trailer tandem 32,400 (1,600 lb of room).
Not legal: the drive tandem at 34,900, over by 900 lb.
The fix: slide the trailer tandems forward. The trailer is supported at the kingpin and at its tandems; the share carried by the tandems grows as the kingpin-to-tandem distance shrinks. Moving the group forward makes the trailer carry more of the load and the tractor carry less, so weight comes off the drives and lands on the trailer tandems, which has the room.
Moving the tandems rearward would do the opposite and make the violation worse - that is the direction drivers often pick by mistake.
The fifth wheel alternative: moving it forward shifts weight from the drives to the steer axle, but you only have 400 lb of steer capacity and you would be eating into front-tire margin for no reason. The tandem slide is the better tool here.
2. You already have a scale ticket in hand and 210 miles to the next scale. Can you roll and fix it later? List the checks before you move.
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No. You now have documented knowledge of an overweight axle. Rolling and "fixing it at the next scale" is a knowing violation, and the overload is not cosmetic - it loads the drive tires and brakes beyond design, changes handling, and counts against bridge structures whether or not anyone weighs you.
Checks before moving:
- Slide the tandems forward the amount needed (a few inches typically moves a few hundred pounds; estimate conservatively), then re-weigh on the same scale if it allows it.
- Confirm drives are at or below 34,000, each axle at or below 20,000, trailer tandem at or below 34,000, steer at or below 12,000, gross at or below 80,000.
- Verify the tires on every axle are rated for the load they are carrying, and check the bridge-formula spacing if the tandems end up unusually placed.
- Inspect tiedowns and the load against the front wall - a 44,000 lb steel stack sitting that far forward is the reason the drives are heavy in the first place.
If the slide cannot cure it, the load comes off or gets repositioned.
3. Suppose sliding the tandems fully forward still leaves the drives over 34,000. What are your options, and what do you tell dispatch?
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If the tandems are all the way forward and the drives are still heavy, geometry has run out of room. The remaining options, in order:
- Use the fifth wheel - forward moves weight to the steer axle - but only if the steer axle, its tires, and its suspension ratings can take it. Here that is roughly 400 lb of headroom, which likely is not enough and may over-load the steer tires.
- Reposition or remove part of the load. With 44,000 lb of plate stacked against the front wall, the load's center of gravity is forward of where the trailer wants it. Shifting the stack rearward, or leaving part of it behind for a second trip, is the real fix.
- Obtain whatever over-limit permission the state actually issues for that route and axle - and only if the highway and bridge postings allow it. Never assume one exists.
To dispatch: state the numbers, the correction attempted, and the fact that the load will not move legally as configured. Ask for a reload plan or a second truck. A missed appointment is recoverable; an overloaded axle for 210 miles is not worth the risk to your brakes, tires, or license.