Playing with a 100 tone crane

[Bodean]

I set up a crane choker on a euc stick as a climber, 30" x 30' for another guy to cut.

The guy had a hard time cutting it, the crane op had too much on it and it popped the stick off the stump,
Squirting the whole inner heartwood tube right out the bottom. My heart sunk, both guys got out of there with pre-planned escape routes.
It also missed the whole side of the apartment building and the gutter. I thought I killed somebody.

I set and cinch the sling in a notch or leave a stub or knuckle, everytime now.

 

[Bodean]

I liked the video, music and fog...

What's with the tarps on the wall? no scratches...?

 

[woodworkingboy]

Cool vid, looks like a fun job. Have definitely seen wire rope slip on Pine bark...up close. Another way to roll to get more bite is to first loop the wire around the pick then over itself, then clevis off a couple feet below. The wire pulls up tight at both points of purchase. Spreads the load with a little backup. Same with taking picks with rope.

 

[cory]

I set and cinch the sling in a notch or leave a stub or knuckle, everytime now.

Good policy.

 

[Mick!]

Cool vid, looks like a fun job. Have definitely seen wire rope slip on Pine bark...up close. Another way to roll to get more bite is to first loop the wire around the pick then over itself, then clevis off a couple feet below. The wire pulls up tight at both points of purchase. Spreads the load with a little backup. Same with taking picks with rope.

In my head I'm imagining a half hitch, but I'm probably wrong, any chance of a little drawing to illustrate that please?

 

[pantheraba]

Thanks, Mick.I was having a little bit of trouble too

 

[RegC]

If in doubt, just have the crane op cable up (pre-tension) beyond the estimated load.....BEFORE you make the cut. If all looks good have him drop it back down to whatever and cut the thing off. I can probably count on one hand the amount of logs I had to notch....and they were short wide ones.

 

[MasterBlaster]

Same here.

 

[sotc]

Yeah, that

 

[Altissimus]

If in doubt, just have the crane op cable up (pre-tension) beyond the estimated load.....BEFORE you make the cut. If all looks good have him drop it back down to whatever and cut the thing off. I can probably count on one hand the amount of logs I had to notch....and they were short wide ones.

... Was thinking of Gerry's pull tree where the D7 guy did the same w the winch. He wanted to know he had the thing.

 

[BlackSmith]

Not all cranes have a scale which makes that hard on the rigging.

 

[cory]

The two times Ive heard of it happening-one mentioned above and one that Tucker told us about happened to his uncle, the pieces had already been picked and were in midair when the logs released inside the bark so I'm not sure what Reg is saying is fool proof.

 

[squisher]

Do you do much crane work Cory? I've had limited experience with it and have only ever used slings or wire rope with a clevis. I'm guessing my limited experience has limited my exposure. Ive never had an issue with slippage and mostly I've used cranes for cottonwoods or lombardis where I'd assume the risk of bark slipping would be high.

 

[cory]

I probably do 10-15 craners/year, use wire rope with clevis 99% of the time. Those 2 incidents above were both tulip trees. If you don't have them out there, they can grow extremely tall and straight with slow taper. So some trunk picks can be totally smooth and straight with no bumps or irregularities and once in a while the bark just isn't up for retaining the log. Where the log has shed bark, the wood feels 2x more slippery than a teflon banana peel.

 

[Altissimus]

So how does a climb lower operation deal w that. Pieces smaller but rigging still has to work. Also why did George Washington plant these things ...

 

[pantheraba]

...frikkin' George!

 

[RegC]

The two times Ive heard of it happening-one mentioned above and one that Tucker told us about happened to his uncle, the pieces had already been picked and were in midair when the logs released inside the bark so I'm not sure what Reg is saying is fool proof.

Its pretty standard, Cory, logical too. If the sling holds good at 2000lb then its not going to come loose if the same log only weighs 1000lb after you cut it. The only thing that could alter things is if your slinging position is poor so the load dramatically changes its orientation after you cut it off. I dont do much crane work now but Ive done lots previous. Never even came close to losing a pick.

 

[cory]

That makes sense Reg, although during pretension, the bark and the whole piece is uncut, after cutting it seems the bark might be more easily shed.

How bout a thought experiment: choke a section that weighs 2000lbs, apply pretension of 4000lbs without causing any issues. Then slack the tension to 2000lbs and deeply girdle the trunk instead of the cutting all the way thru the pick, then apply 4000lbs of tension, perhaps the bark would be pulled off the piece.

Not doubting your process, Reg, just thinking about the issue. The species in question is key- tulip. Ive never had logs slip out of a crane pick thank god, but it is common to see tulip logs lose large shells of slippery bark when they are dumped in a log pile.

 

[RegC]

That makes sense Reg, although during pretension, the bark and the whole piece is uncut, after cutting it seems the bark might be more easily shed.

How bout a thought experiment: choke a section that weighs 2000lbs, apply pretension of 4000lbs without causing any issues. Then slack the tension to 2000lbs and deeply girdle the trunk instead of the cutting all the way thru the pick, then apply 4000lbs of tension, perhaps the bark would be pulled off the piece.

Not doubting your process, Reg, just thinking about the issue. The species in question is key- tulip. Ive never had logs slip out of a crane pick thank god, but it is common to see tulip logs lose large shells of slippery bark when they are dumped in a log pile.

If the barks that weak Cory, the sling generally cuts right through it with excessive choking of a sling or chain....so the sling ends up biting into solid wood as opposed to a piece of bark.

 

[climbernz]

I liked the video, music and fog...

What's with the tarps on the wall? no scratches...?

last time we were there a colleague put a small mark on the newly painted wall................ the owners demanded that the entire wall be renewed and unfortunately we couldn't do anything about it, in the end it cost a very very large sum of money , just for a little scratch ..... Only in Germany