The concrete staves fit together a bit like tongue and groove lumber. Each one has an edge that is just narrow and plain....
...and a side that is thicker and has a groove that receives the narrow edge of the adjacent one.
The lower fifteen feet or so of the inside of the silo is really showing deterioration. Silage is acidic and that environment eats concrete over time. The inner surface is spalling off and making the staves thinner.
"Oh my gosh, that shape - if I squint I think I see....Elvis?!"
The squares areas are wooden doors that can be removed wherever the forage level is when you need to access the silo as it's being filled or emptied. The bottom two (above) have been taken out and you can see the staves that form a tube surrounding the access ladder. They are undamaged by time and acid since forage never touches them.
The view looking straight up at the scaffolding the Hoovers will walk on to disassemble the silo. It's essentially a very strong pipe that the spoke assembly ratchets itself up from the bottom. Each time it's raised a pin is put through the shaft so it can't drop, then it gets ratcheted up again. It's a bit hard to describe but basically it climbs the pole and the workers get on and off it wherever it is through the little square doors in the wall.
These skinny little arms look wholly inadequate for anything but their only purpose is to keep the center pole from wobbling or starting to bow. They don't carry any weight. You can see the small square wooden doors better here. Also notice that the staves aren't so badly eaten up higher in the silo. They have not spent as much time in contact with silage as the lower staves.
The Hoovers indicated they would need a bigge pile of dirt to drop the staves onto so Andy went to a field that had a ridge of earth built up from plowing and scraped some up.
Gotta love hydraulics!
To answer Bow Street Flowers' question - in our experience around here most Mennonite groups allow powered vehicles but they have to ride on steel, not rubber. As best I understand it, it has to do with staying in contact with the earth. The Amish orders tend to be more strict than Mennonites and allow gas powered engines - for example, hay balers - but they are stationary during work and the Amish use draft horses instead of tractors or other powered vehicles. Mennonite folks have all the "modern" agricultural equipment - tractors, combines, riding lawn mowers - but they all have steel wheels. This is a real problem on paved roads and some are adapting to rubber tires BUT with steel knobs or cleats embedded in the rubber so they are still compliant with the Mennonite tenet of always touching earth. To travel on public roads for activities such as this they hire drivers.