This is a real puzzler. No moving parts, no adjustments possible, and those barbs in the center shaft... Can't be a trap, and I can't believe anybody put a piece of meat into a well in a way it would be in direct contact with the water, and besides, the iron would rust away.
No need for the barbed shaft in digging post holes, but the barbs would hold something to be withdrawn.
Some kind of drain cleaner could use these elements, but 26 inches long won't follow many curves or angles. It won't reach very far either. It's usefulness would be limited to 14 inch plus or minus drains. There might have been an extension that fit over the square piece at the top, but it wouldn't take a lot of torque. Did it originally have a T handle?
Any way it could have worked with silage, cutting in to pull out a chunk?