The background: My small Iowa town wanted to dispose of its old, iron, enough-momentum-to-crush-bones merry-go-round, so they put it up for auction. A relative of mine put in the only bid. Being the handy ones, my father and I got the job of disassembling it, with an eye towards eventually putting it back together again somewhere new.
Step 1: Remove Planking
The wooden planking was in mixed shape. Some had been recently replaced, and some was rotting away. A Sawzall and a crowbar made quick work of it.
Step 2: Remove Wood Frame
The underlying boards were in remarkably good shape, considering the age of the thing. However, we weren't going to keep them. Two cuts with the Sawzall to separate them, and the square-nutted bolt through the pipe came off easily with a crescent wrench. That allowed the wooden frame to drop off. In the photo you can see the 2 "butterfly" pieces. Like most of the machine, they're good cast iron. There is another L-shaped piece that wraps around the outside of the joint and reinforces the bottom side. It has 2 knobs sticking out which helped it align the mitered wooden parts.
Whoever assembled this used the wrong size of carriage bolts, so the square heads of the bolts just spun around in the square holes in the casting. To get these old bolts off, I had to grab the round end of the carriage bolts with vice grips and use an impact wrench on the nuts.
Step 3: Bottom Hub
With the wooden parts removed, it was time to start on the pipes. First, we removed the bolts that ran through the bottom hub of the central shaft. They ran up from below through a hub, a bracket attached to the radial boards, and a casting at the bottom of the S-shaped pipe.
Step 4: Handrail/Crossbraces
There were little short pipes between the spokes, held together with a pair of castings. 2 bolts, and off they come.
Step 5: De-Spoking
Having removed the crossbraces and the bottom hub bolts, the spokes are held in by only one bolt each in the top hub. Remove that bolt, apply a bit of force to break through decades of crud, and they come off.
Step 6: Hub
Hopefully by now your merry-go-round has been reduced to a funny-looking post. The post was actually composed of 4 sections: a top hub casting, a chunk of pipe, a bottom hub casting, and a central pillar running through all three, which was embedded in concrete. The hubs and larger pipe just lifted off the central pillar.
Notice that there are 3 grease fittings; 1 on top and 2 on the sides. The 2 on the sides of the pipe had been painted over and not greased for years. Naughty park custodians.
Step 7: What's in the Hub?
We pulled the small bolts connecting the top hub to the pipe, and peered inside. It turns out that the hub is the world's simplest ball bearing. There's a cup in the top of the central pillar, a ball bearing the size of a ping-pong ball, and another cup inside the top of the hub. Fill it with grease, and it will serve for decades.
The cup in the top of the pillar is a separate casting, which came out pretty easily. The top of the pillar was milled down to give the connecting bolts some clearance (we think).
Step 8: Pillar Removal
We can't really just leave a steel pipe sticking out of the ground in the middle of the park, so we had to cut it off. A big angle grinder was the tool of choice, with additional motivation from a sledgehammer. It still took 20 minutes. As we discovered, that was some HEAVY pipe, with 5/8" thick walls.
And that's the end of it. Now the pieces will sit in our shed until we figure out where they're going.