Topping a 90' pine

[cairologger]

Good afternoon all,

I have removed a lot of tall pines here in south ga, but saturday I had something happen that I have to get some input on. I have a 57' wh bucket truck and on a average (75-80') pine I use a 3" 27,000 nylon strap or a 1" rope to make a hinge in the tree and just let the top fall over against trunk and then trim it down from there. I had a extra large one ( 52" base at 3' from ground and 30" at 50' and 90' tall) this weekend and had room around it to throw the top down, I wanted to hinge it because I had never done one that big. I put the stap in position made the back cut and got down and moved the bucket truck. I had a 1" rope up in the top and hooked to the backhoe about 150' away, pulled it and it hinged over and kept right on going to the ground. It was a never used strap and did'nt even slow it down. Top was around 4000lbs. Would a 10-12" strap (80,000lbs) have stopped the fall? Or what would have worked better?

Thanks,Jake

 

[Youngbuck20]

i think the shock load would be so large your tree might just give out.

 

[gorman]

learn to climb.

 

[Youngbuck20]

learn to climb.

good call

 

[Slvrmple72]

That would have been an awesome video if an unoccupied house was the target....

 

[treemandan]

It must be a hairy feeling cutting a wedge, making the back cut and then moving around under that large top folding up the bucket truck to get down. It's going to turn out real ugly one day.

Some people you just can't reach.

 

[cfield]

Good afternoon all,

I have removed a lot of tall pines here in south ga, but saturday I had something happen that I have to get some input on. I have a 57' wh bucket truck and on a average (75-80') pine I use a 3" 27,000 nylon strap or a 1" rope to make a hinge in the tree and just let the top fall over against trunk and then trim it down from there. I had a extra large one ( 52" base at 3' from ground and 30" at 50' and 90' tall) this weekend and had room around it to throw the top down, I wanted to hinge it because I had never done one that big. I put the stap in position made the back cut and got down and moved the bucket truck. I had a 1" rope up in the top and hooked to the backhoe about 150' away, pulled it and it hinged over and kept right on going to the ground. It was a never used strap and did'nt even slow it down. Top was around 4000lbs. Would a 10-12" strap (80,000lbs) have stopped the fall? Or what would have worked better?

Always more than 1 way to do a job, but your gonna take sum heat posting that lil trick of yours. All the bs aside these guys just want you to be safe. Just sit and think for a minute if a 4000lb to hit the boom. We've all got away with some "hero shots" or questionable calls. Take this experience and learn from it like a true professional would. Be safe!

 

[Pelorus]

Don't buy green bananas, and please ensure your Last Will and Testament and Power of Attorney paperwork is up to snuff, and that you have an excellent life insurance policy.

The fire chief from a volunteer fire dept in Seguin Twp, Ontario got himself killed a couple of years ago while tackling an oak tree that was a lot taller than the bucket he was in.

Correction: it was a Hydro One worker not the fire chief who died while moonlighting with a Hydro One apparatus. I think this incident was kept pretty hushed up, but I talked to a member of Seguin FD who attended that call, and it was as bad as bad gets. The ground guys tried to lower the bucket from the ground after he got whacked, but he screamed and that ended thatattempt. Next the Sequin FD showed up, who had at least one experienced tree guy on scene. (the guy that I talked to) He was not allowed to climb the tree. So a high angle rescue team was brought in from somewhere, and Lifeflight heli, etc. Guy was pronounced dead on scene from injuries that were likely fatal even if he could have received definitive aid right away.

 

[mr. holden wood]

Good afternoon all,

I have removed a lot of tall pines here in south ga, but saturday I had something happen that I have to get some input on. I have a 57' wh bucket truck and on a average (75-80') pine I use a 3" 27,000 nylon strap or a 1" rope to make a hinge in the tree and just let the top fall over against trunk and then trim it down from there. I had a extra large one ( 52" base at 3' from ground and 30" at 50' and 90' tall) this weekend and had room around it to throw the top down, I wanted to hinge it because I had never done one that big. I put the stap in position made the back cut and got down and moved the bucket truck. I had a 1" rope up in the top and hooked to the backhoe about 150' away, pulled it and it hinged over and kept right on going to the ground. It was a never used strap and did'nt even slow it down. Top was around 4000lbs. Would a 10-12" strap (80,000lbs) have stopped the fall? Or what would have worked better?

Thanks,Jake

My hillbilly is a bit rusty, if you could convert this post into english I might be able to help. From what I can gather common sense is all you need.

 

[Rickytree]

If the bucket was 55 or 60 and the tree was 90 feet then that's a 30 or more foot top and more than 4000 pounds. I thinks. Why use a strap on? he he. Block and whoopie.

 

[rtsims]

So if im picking up what your laying down. You basically tied the top off to the stem, no block, no way to lower it, no way to let it run AT ALL? Thats alot of weight with some pretty good momentum coming to a screaching hault. Seems pretty silly in my book!

 

[k5alive]

you've gotten to used to a bucket, that's a bad thing. why couldn't you climb that 30' and safely peice it down
in a situation like that s**t can go awefully wrong mighty quick.

 

[cairologger]

Thanks, for all the replies, this is standard procedure in my area, leave a lot of hinge drive wedges in the back cut and have a 1" rope in the top hooked to a 4x4 or in my case a 4x4 backhoe and pull hard to make the hinge break. I thought it was better to be 150' away than hanging around up in the action. When cutting smaller stuff (average 12"-18") just put a 1/2" rope in the top leave a 1" hinge and wedges in the backcut, swing bucket back and ground crew pulls the top out by hand, has worked great so far. We have had quite a few more climbers injured down here from mostly cuts and getting slapped around by ropes and limbs. I think the only bucket injuries have been power lines.

 

[MarquisTree]

The issue is you are grossly overloading your rigging gear. Slings are not designed for shock loading. I would question your estimate on the weight of the top. Most people drastically underestimate the weight of the brush on pine tops. (I could be totally wrong here since I have almost no info on the tree you were working on)

Envisioning a 52" dbh pine. Putting a 60' bucket next to it at Max height, in my experience you would most likely have 6k-12k of tree above you. Typically obviously every tree is different .

So let's say the top did weight 4k and you rigged it so it only fell 4' and the sling stopped it in 6". In that case you would put roughly 32,000 lbs of shock load on the sling.
If the top weighed 8k the shock load would be around 64,000 lbs .
No tree guys are working with any rigging that has a SWL rating any where near these loads.
The reason you get away with it for awhile is rigging slings generally have a 5 to 1 safety factor figured in (sling is rated for 10k breaks at a single cycle of 50k).
The practice you described is unsafe and doesn't follow any of ANSI's standards. If you have an accident using this method you are at risk of being found grossly negligent.

 

[MarquisTree]

Energy of falling object

Rough numbers here
Doesn't calculate all the forces involved but close enough for what we do

 

[ATH]

had room around it to throw the top down, I wanted to hinge it because I had never done one that big.

The other thing I don't understand is: If there was room to drop the top, why did you even tie it off? Why not just let it free fall? Was it really just because you wanted to test the upper limits of your equipment? If so, I guess you now know. Don't do that again.

If there was enough room to drop the top, was there enough space to just drop the tree from the ground?

I was jokingly going to suggest logging chain next time, but I am affraid you will take that seriously. IF your rigging lines held, you are risking the tree breaking in half or uprooting with that much force on it (as was stated above...but just wanted to highlight that piece again).

 

[lloyd786]

Weight + friction = heat

The next time you do a hinge with a strap have a ground guy lower the top a little. Feel the bullrope as it slides through the strap. The friction at that point can generate a huge amount of heat. I imagine with several thousand lbs. it would only have to slide a few inches to melt through a nylon strap. That's my guess as to what happened. Just the slide produced in the process of stretching the bullrope is enough. Is there any sign of melting on what's left of the strap ? That's why most use a block. The ropes will last longer also.

 

[TheJollyLogger]

I'm still wrapping my brain around this one. Started calculating forces and got lost in the math. At this point I would be worried about the spar failing. my best estimate is 50 to 60,000 pounds of force at the time it failled. my golden rule of climbing has always been climb higher cut smaller.

 

[Tree Pig]

I'm still wrapping my brain around this one. Started calculating forces and got lost in the math. At this point I would be worried about the spar failing. my best estimate is 50 to 60,000 pounds of force at the time it failled. my golden rule of climbing has always been climb higher cut smaller.

Well that works if you climb. But if you only ever used a bucket then you either buy a taller bucket or go as high as you can and murph it out with a tow strap tied to it and keep your fingers crossed. More evidence that just owning the equipment doesnt make you a tree guy. I doubt this guy realizes how dumb what he did is.:jester::bang:otstir::deadhorse:

 

[MarquisTree]

The next time you do a hinge with a strap have a ground guy lower the top a little. Feel the bullrope as it slides through the strap. The friction at that point can generate a huge amount of heat. I imagine with several thousand lbs. it would only have to slide a few inches to melt through a nylon strap. That's my guess as to what happened. Just the slide produced in the process of stretching the bullrope is enough. Is there any sign of melting on what's left of the strap ? That's why most use a block. The ropes will last longer also.

I don't think he was using any sort of lowering line. I have seen guys do this before. They take a heavy sling and choke one end to the butt and the other end a few feet above the cut. They just crash the whole top. There is no way to reduce the shock load because there is no lowering line. Then they just cookie the whole thing up until they can undo the sling.
Very scary thing to watch someone do.
I think the force estimates I gave are conservative I think in most situations you would end up with more then a 4' fall