Pulling Tree Stumps Safely

[BigMccorm]

I was taught that to prevent the whipping action if/when a chain snaps one way is to put a blanket over it. We use an old army surplus blanket. I guess it is supposed to absorb some of the energy of the chain. Couldn't tell you if it works or not because I have never snapped a chain (knock on wood).

 

[IslandTractor]

I was taught that to prevent the whipping action if/when a chain snaps one way is to put a blanket over it. We use an old army surplus blanket. I guess it is supposed to absorb some of the energy of the chain. Couldn't tell you if it works or not because I have never snapped a chain (knock on wood).

Given the massive stored energy in a chain stretched to breaking, I would imagine that all an army blanket would do is provide you with a quarter inch of blanket between your head and a thirty pound mass of chain travelling at over a hundred miles an hour. No way a blanket would slow down or stop a lethal shot of chain.

 

[TheDingy]

I just now remembered this, Mythbusters did a special on a cable breaking that was very extensive. There was nothing that could kill you. They were doing this with very heavy cable that I would be comfortable pulling on stumps with.

 

[N80]

I think the Mythbusters determined that it would not slice you in two. I saw that episode and I don't think they made any determination on lethality...at least in my opinion. Blunt trauma can kill you just as well as penetrating trauma.

What I don't remember was how they got the cable to its breaking point. It seems like they did it in a fairly continuous, steady fashion. Is that right? Or maybe they cut it. Anyway, I'd be more concerned about a breakage due to a sudden, violent shock load.

Regardless, I would not want to be hit by any of these options.

 

[greggh]

At this point if the trees are already cut down, I would suggest that you dig around before removal. If that is not a solution you would like to pursue, then I would hire someone with a BIG dozer to finish the task.

By the way if you want to see sparks fly on a dead tree, we have one that is called Bois d'ark (pronounced bow dark, unsure of the spelling) in my area. in the days before t-posts, they were used. They would shrivel up and were tough as iron. I never saw anyone drive a steeple into them if repairing wire fence. They had to tie the wire up on the post. Sometimes it was called iron wood.

 

[psj12]

I cut the tree 8 to 10 feet high. Wrap the chain (a long one) to the highest point you can reach. Pull it over with your tractor. I have removed quite large trees with this method. The long trunk gives you a huge lever. usually the whole stump and roots come up on the first try. If it doesn't try pulling it from the other side. After a few pulls from different angles you will find the wealk point.
On another point chains don't tend to strech and store energy. When they fail they yield and then break. Use a large enough chain.

 

[IslandTractor]

On another point chains don't tend to strech and store energy. When they fail they yield and then break. Use a large enough chain.

Are you sure that is correct? I know that marine chain is rated by several parameters and one of them is % stretch before failure. All that energy from pulling with 40hp or whatever your tractor puts out has to be stored somewhere if you are tugging away at a stump. The stump itself must have some of it but a sudden failure in the chain must release a fair amount back towards the source of the energy too (ie tractor).Any physicists, mechanical engineers or material scientists out there?

 

[gemini5362]

I just now remembered this, Mythbusters did a special on a cable breaking that was very extensive. There was nothing that could kill you. They were doing this with very heavy cable that I would be comfortable pulling on stumps with.

AS a rule I love the Mythbuster program and find it very interesting. However on the cable breaking show I have a tendency to disagree with them. Anyone that spent time on a naval ship or other big ship can probably tell what a breaking cable looks like. There are plenty of documented case of what happens on an Aircraft carrier when a catapult cable breaks or an arresting cable.

 

[gemini5362]

Are you sure that is correct? I know that marine chain is rated by several parameters and one of them is % stretch before failure. All that energy from pulling with 40hp or whatever your tractor puts out has to be stored somewhere if you are tugging away at a stump. The stump itself must have some of it but a sudden failure in the chain must release a fair amount back towards the source of the energy too (ie tractor).Any physicists, mechanical engineers or material scientists out there?

I believe the difference is in the way chains are made and cables made. I am no engineer but I have seen chains break and they jump then seem to fall down. Cables tighten to a smaller dimension before breaking and that seems to allow more stretch. Cables will whip pretty bad when they break. To see something really stretch watch a piece of nylon rope break especially the bigger stuff like 4 inch in diamater. It is similar to watching a rubber band snap

 

[Reg]

One solution is to use chain that will NOT break, i.e. has a rating way beyond what your tractor can possibly put out - and do NOT jerk it.

Another is to thread rope through about every 4th or 5th link, tie it off to the tractor and to the load with an extra 2 or 3ft of slack at each end. More time and trouble than the army blanket, probably safer - as long as you use appropriate sized rope. I think this is more predictable, but still favor the chain that is so overspec'd that you will not break it without jerking - and just don't do that.