Caterpillar power all the way
Light-weight on the truck itself is 26,500 lbs.
A typical heaped tri-axle load of PA bituminous coal gross weighs at roughly 70,000 lbs or so. It's hard to get the legal 73,280 when you are hauling prepared soft coal, if it is a nice load with lots of lumps. Thus the reason why it is stacked to the moon in those photos.
Anthracite is usually heavier so there isn't much trouble making legal weight, and then some. When we still hauled coal out of the Pine Creek breaker, we topped the loads off by hand with a shovel as it came off the shaker. We got to be so good at judging it that we could usually come out within 100-200 pounds variance from one load to the next.
Sorry Dremel for hi-jacking your thread