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Challenge seems to be how to cut them in half. I tried using a recipricating saw, but that did not work at all. Too weak.
Obviously I cant use a table saw, or a circular saw since they have the narrowness limiting their use.

Any ideas or suggestions from people who have cut larger size wine barrels in half?
On trying it again, this time with a simple handsaw, i see the problem is being caused by the slats creating the barrel caving inward after two or three are cut through.
Effectively wedging the blades used to cut. The barrels are made of wooden slats, averaging @ 1″ – 3.5″ in width, running from top to bottom. And as the barrels are a bit old & not securely bound together all around, individual wooden planks move like loose teeth rather than being securely attached to neighboring planks. Thus wedging blades with their relative freeplay.