The manual lift in action
When you are out in the field or you are not near a splitter with a lifter, sometimes you need to get rounds up in the air (truck bed, on a stack of pallets, etc.). This manual firewood lifter gives you about 4:1 mechanical advantage allowing you to lift rounds you normally could not budge yourself. When constructing this lifter, you want to choose very light and dry wood. Dry Cedar 4x4's would be a good choice so that you don't add any excess weight to the round that you are lifting.
When I first came up with this idea I was watching a show where a team of people were trying to lift a pickup. They had put some blocks under the back of a small pickup truck probably a Datsun or a Mazda - well, maybe even a Toyota, and created a 36 (roughly) foot long (what looked a like a ladder rotated 90° from west to east with support 2x4's along the center. There was a significant amount of bend in their structure but with a large number of people pressing down on the end of the 36 foot length, the pickup was raised into the air and I thought to myself, I bet I could adapt this philosophy to lift heavy firewood rounds - and behold, the manual lifter was born. I built 3 of these: 1x 8' for a trailer and 1x 12' for a trailer, and 2x 12' with the support plank at a different height on my F350.
The interesting part was the responses I would get when picking up firewood. People would walk by and say, what's is that! Some tree services guys thought it was awesome so all in all, it has turned out to be pretty good invention. Maybe you can get some benefit out of it as well. When you build a manual lifter, go out of your way to make sure you are using very light dry wood (preferably cedar, although I understand its expensive).
Physical Usage Instructions
Place the lifter flat on the ground behind your truck with the tailgate taken off if possible. Roll your firewood round in front of the 2x12 plank sticking up. Walk to the end of the lifter that is away from your truck. Pick up the end of the lifter and walk slowly towards the truck repositioning your hand holds one at a time. Make sure the round is balanced, especially if it's odd shaped so you don't lose it on the way up.
Your lifter should now be straight up in the air and the 2x12 plank should be on the bed of your truck. Roll the round off of the plank and move it to its final destination for the ride home.
Depending on the size and variety of trucks and trailers you have, making 3 or 4 of these for various heights would be beneficial.
For a truck - I recommend 12' in length and about 16-20" for width. The firewood round support plank should be about 30 - 36 inches depending on the height of the truck. Some flatbeds are much higher than box trucks.
For a trailer - there are lower beds and higher beds if you have the double doors.