Hook for use in clearing a field. The ring was to attach a team of horses to help pull stubborn rocks or stumps out of the ground. That would be my guess.
Looks too hefty for a manhole hook, plus it was found on the edge of a farm - just where one would expect abandoned field-clearing gear.
So this was a great puzzle. It definitely is not a hand tool because of the attached ring and the angle on the bottom part is too steep and flared for prying things. Then if you look at the hole on the bar - it is carefully forged to ensure the directionality of the bottom edge.
Also of interest is that Harborton (the town where it was found) is in Virginia which is coal country. So I started thinking about coal mining - but could come up with nothing miners would use this for. Then I looked around and Viola - I think this is IT.
If you look at that image - there is a mining car on inclined rails. Look at how the car is chained and you will hopefully see this part. This part is called a fishing hook for a mining car here. If the car came loose or the engine failed or it was parked - this thing will fall to the ground (sleepers) and lodge into the tracks so the car would stop rolling backwards (Reminds me of Kramer giving Newman a ride on the rickshaw and what followed :))
I do not have first hand experience and could definitely be wrong. Just going with my engineering intuition here. It could also be a hook to hold other types of carriages from rolling back on slopes.
It has the shape of a tire iron used to mount tires on a rim. That one might be used for tractor tires or construction equipment. The ring doesn’t look very utile, just something to hang it on the wall. The flattened end seems too be too thin for anything that would be lifted with a pry bar that heavy, and the arm is too short to get enough leverage on very heavy items. It might also me a metal working tool for pulling dents in heavy metal.
This is a darn good theory. The only problem I see is that the loop on the end doesn’t seem like a good way to attach it because it wouldn’t ensure that the hook dropped straight down. In your picture, the end is attached by the shaft being bent 180 degrees around an attachment point on the cart, ensuring that the only way for the hook to fall would be straight down. The loop would probably still work, but seems an odd way to go about it.
Unfortunately, “mine cart fishing hook” is hard to search, most of the results are for hooks to catch fish with. The only hit I got regarding mining was the page you linked to. I noticed that your link is for a book written in 1993 for small scale mining, I wonder if larger or older mining operations had a different name for it. I tried “mining cart sleeper hook,” “emergency hook,” “parking hook” and some others but got no results.
These look similar:
The second the last tool on this page looks very similar.
It says it’s a reef tool, used for caulking and plumbing. 
Clearly it’s an art project.
Unfortunately it was found on Virginia’s Eastern Shore, far from coal country. It’s tidewater, rural, with one small rail line and an economy based on fishing and agriculture at most.
Does the back side of the bend show signs of having been hammered?
I thought someone else might ask this, but what hole?
The only hole I see is the one through which the ring is threaded (well, and the whole hole in the ring).
I guess am77494 might be saying that the bend in the bar is deliberate and not the result of damage.
It doesn’t appear to be any kind of hay tool, or manhole/grate pry tool, or the reef tool. All of those have points on them. This has a flat.
It looks like maybe a kind of pry tool - hard to tell because the enlarged picture has a caption box over that part of the image.
I agree the curve in the shape appears intentional.
I agree the ring is purposeful, not merely decoration or for hanging on a wall. I would suspect for attaching with a strap or anchoring in some manner that allows the thing to rotate/swing.
The mine cart emergency brake (fishing hook) looks just about right. That line drawing is hard to tell, but if you look in the area of attachment in the bottom of the cart, it could be a ring that is anchored by another loop of metal to the cart underside, allowing the tool to float with the chain during pulling and hauling, but guiding the point down as it falls free to find the anchor. To me, that is the most likely.
I think the hole through the tool that the ring is set in would control the angle of the fall if the ring were anchored flat against, with a loop to secure it. Imagine the hand in that picture as a solid metal flange bolted flat to the cart. The ring would rotate around that pivot, but not twist out of plane. The bar would fall straight, but would have some side to side float when the chain is being pulled on, like going around turns.
Mystery tool mystery solved with video explanation!
Large baling hook?
That curved, non-sharp, end looks like it might be useful in moving around large, possibly wet, pieces of netting or sailcloth without causing much damage.
Wow!
I’m beginning to think there’s no mystery that can’t be solved here.
Thanks!
No, because the distance the device would push the bundle is too small, it would just make a dent which springs back to original when the force is released to move the fulcrum …
The circular handle shows that it was not for use with any machine or wire attachment or anything. The ring is just a quick cheap handle to add, for tying it and for giving people the option to hold it with their palm at various places (angles… as wrists and hands can be at various angles on arms…and arms vary their angle to the body…)
Its not a lever designed for water grates, as there is no use for the fulcrum with the grate… The grate’s surrounds provide the fulcrum… Well if the surrounds were damaged and eroded then you might need to provide a fulcrum.
But no you can tell it is for plumbers… for putting pipes in the ground. The curve allows for the handle to go straight up … where as the straight bar has to be at some great angle to get under a pipe…
This fulcrum is for lifting pipes… You put the sharp end under one end of the pipe, and lever it up, and then the pipe can be shifted more easily.
It could be used for root removal, perhaps what it was used for at the farm.
Another nice SD moment of fighting ignorance: extremely bored, figured I’d check the thread anyway. Still kind of boring, except for…
“Gandy dancers!”
ETA: "kind of boring, " of course, is a YMMV.
I’m pulling, not pushing.
The edge on the business end looks dull to me. It’s a poor picture, but you could be right. Wouldn’t want something like that anywhere near sailcloth or nets.
Um, it was answered with a video demonstration a few posts ago…
Multi purpose lever used in wells and miscellaneous uses on farms.
