posted 3 years ago
A gin pole as shown would be the way to go for you. Since you don't need to lift the posts off the ground, but just get them upright in the holes, you wouldn't necessarily need to be able to lift the full weight of them.
The first thing to do would be lay out the locations and ground elevations, figure out how much you need above ground at each point, and cut each pole to the right length including the hole with say a foot extra just in case. There is zero benefit to lifting a post much longer than you need. I would guess that you need around 2 x 9' plus 6' in the ground, maybe 2' for a raised floor if you want that, equals 26'. That is a LOT less than 45'. Cut off the tops, as the bottom has the strongest treatment and will last the longest in the ground.
Telephone poles are regularly set directly in the ground without even gravel, let alone concrete, and stay upright for decades without bracing. I think concreting them in is a bad idea, as it will positively trap moisture in the wood. I would just backfill with larger crushed gravel tamped in; this will lock together and stabilize the posts forever. They will brace each other with the framing and sheathing. You can add diagonal braces if you want for extra insurance.
I would dig the holes and cut a small angle in on the side opposite the gin pole, put in a stout plank opposite the ramp, and pull the base of the pole so it hits the plank. As it rises, the plank will brace the base of the post, and at some point it will drop in and sit vertical (more or less). Then you just have to pull the plank, plumb the post, and backfill.
If the posts are really heavy, I might use two gin poles, one directly above the upper post as it lays on the ground, and one next to the hole. Raise the post as high as you can with the first, and then the second will have an easier time raising the post to vertical rather than having to pull at an extreme angle from the ground.
Another way to handle the raising would be to set the gin pole base straddling the hole, connect the top of the gin pole to the top of the post so the gin pole is at a 45 degree angle or maybe higher, and pull on the top of the gin pole so both gin pole and post tilt at the same time. By the time the gin pole is vertical, the post will be up at 45 degrees, and the lifting will get significantly easier as the weight of the gin pole is helping raise the post. At some point the post will fall into the hole vertically and the gin pole will go slack and drop.