I had a 26" diameter maple fall in my forest. I cut it into 9 foot lengths. It's now a very nice table on my patio. The very first stage of that project several years ago was realizing that my mini excavator could not possibly lift it to load it on a trailer, and it was too heavy to skid back a half mile with the tractor. So, being rather eager to get it back, and knowing that it would not fit in the sawmill anyway, I split it in half where it lay. It took me two days, and a dozen progressively wider maple wedges. In two halves, the mini ex, and the trailer handled it.
I learned the "it's heavier than in looks" lesson early in life. My buddy had his dad's brand new half tom GMC pick up. We needed some fill for a project. Who do we pass, a road works guy with a back hoe. "Hey, can you spare us a bucket of what you've dug out there?" "Sure!", and he skillfully, and oh so gently pours a bucket load into the box. "You want a second bucket load...?" As I said to my buddy, Ahhh, I don't think that's a good idea, my buddy's already motioning yes. A second really gently poured load of fill had the truck bunged right out with the frame on the axle. It made the trip, but had to have the springs replaced that week.
I work in aviation, where we tend to the more cautious, and weigh everything. My uncle, who was a mechanic on the Berlin Airlift told me about a DC-4 which staggered into the airport with a terrified crew. Apparently the load of aluminum bar which was loaded, and weight calculated was actually steel.