Calculation of pic weight accuracy

classictruckman

Participating member
There's a tree company here that rolled their crane while removing white pines for hydro one, in the news paper article he was quoted saying "we work with a safety factor at all times, there is a 15% safety factor built into the crane's load chart".

That 15% is there to make up for being slightly off level, minor ground imperfections, crane age, etc. You should not be counting on it to save your ass.
 

treevet

Branched out member
Location
Cincinnati, Ohio
There's a tree company here that rolled their crane while removing white pines for hydro one, in the news paper article he was quoted saying "we work with a safety factor at all times, there is a 15% safety factor built into the crane's load chart".

That 15% is there to make up for being slightly off level, minor ground imperfections, crane age, etc. You should not be counting on it to save your ass.

hence the qualification of my statement
 

treevet

Branched out member
Location
Cincinnati, Ohio
I really wanted to avoid saying this for all the anal rententive types and pseudo tree/crane guys and youngsters...but alas I cannot. Truth be known, back in the day and more often than not today in tree/crane work much of the work is NOT done with charts and NOT done with greenlog wt. tables but rather by experience...starting small and working up a little and also by the "feel" of the crane. I can/could feel my cranes under my feet. Crane guys I know, and I know a lot ...work mostly by feel and experience. Wannabe treecrane guys and forum treecrane guys....well they are gonna say what they think they are post ta say. (...lol)
 

allmark

Participating member
The seat of the pants or "feeling the crane " might have been ok on the old cranes but not so good on the newer ones. The old cranes were much stronger and heavier built. The newer cranes are designed and calculated in much closer tolerances.
 

treevet

Branched out member
Location
Cincinnati, Ohio
none the less the majority of picks are made that way in tree ops (not picking ac units) and furthermore...how is foliage calculated? Big factor. The majority of picks are way under the chart. Periodic checks of chart and table enhance "feel" picks. When picks become marginal...which is and should be...seldom...then all the calculating comes into effect. This is a vast minority of picks.
 

treehumper

Carpal tunnel level member
Location
Ridgefield, NJ
One man's lifetime of experience doesn't amount to much more than a day for the industry and there are plenty of days that nothing goes wrong. This isn't about individuals it's about the whole industry and today's equipment. Once upon a time, all you had to go by was "feel" and experience. We overbuilt everything based on that, whether it was a crane or a building. Today's gear, like much of what we engineer, is designed to be operated in a way that works with factors and sensors, the new "feel" as it were.

Why continue to operate the old school way when the equipment is not? While it's excellent to know how if ever the need arises (much alike to teaching your kid how to drive manual transmission) it's foolish to not learn and utilize the latest tools available.
 

treevet

Branched out member
Location
Cincinnati, Ohio
Do you check the green log weight table on every pick and then check the chart then confirm the pick weight afterwards? Do you even do any crane work?

Like I said, it is good to occasionally check "pic (pick) weight accuracy" (topic) for future reference...but regardless of your statement re contemporary equipment and the need to "learn and utilize the latest tools available" the fact still remains that the only way you will know the REAL green log weight (or green leaved weight) is AFTER the pick (with no ability to turn back). Most often the piece is taken to fit into an LZ or on a log truck etc. so imo...charting and guestimating weight on EVERY pick...a little silly and even unprofessional. Get the thing down and move on.

Op to newby crane climber: "whatcha ya got there son?"
NCC to Op: (shaky voice)..."I got about 3k here sir, hu hu hu hu how much we good for?."
Op to NCC: "We're good for 12k, now cut the damn thing off and let me get back to my newspaper."
 
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treehumper

Carpal tunnel level member
Location
Ridgefield, NJ
Do you check the green log weight table on every pick and then check the chart then confirm the pick weight afterwards? Do you even do any crane work?

Like I said, it is good to occasionally check "pic (pick) weight accuracy" (topic) for future reference...but regardless of your statement re contemporary equipment and the need to "learn and utilize the latest tools available" the fact still remains that the only way you will know the REAL green log weight (or green leaved weight) is AFTER the pick (with no ability to turn back). Most often the piece is taken to fit into an LZ or on a log truck etc. so imo...charting and guestimating weight on EVERY pick...a little silly and even unprofessional. Get the thing down and move on.

Op to newby crane climber: "whatcha ya got there son?"
NCC to Op: (shaky voice)..."I got about 3k here sir, hu hu hu hu how much we good for?."
Op to NCC: "We're good for 12k, now cut the damn thing off and let me get back to my newspaper."
Yep, do and have done plenty. With veteran ops and with newbies to trees. checking pick weight throughout the day is good. When I get to the wood, I'll reference the log chart in my head, check it against the actual then adjust my calculations. There's plenty of time to figure out the weights between picks. As for the LZ determining pick size, sure. I've worked with LZs that leave me with tons of room to go as big as I can (thus the need to calculate pick weight) and those that limit the crown picks substantially. Being able to run the numbers makes for more efficient operations. But those numbers are relative to the equipment used, the wind, the time of year, LZ and it's distance along with the farthest pick on the tree. So, instead of the op being snide with the newbie, he could put down his paper and teach the kid something.
 

Mark Chisholm

Administrator
Administrator
I did a few removals all tangled up in the powerlines today on a backyard circuit. I was working with my "normal" guy with a 50t grove. He was close. Working with him so many times I knew he was good for over 9k. We talked before I went up and decided to cut the first top between the wires. When I was ready to cut, one of my guys yelled up to me to see how much it should weigh. I was not really thinking about it. I just knew we were good for this. However, leaves are out now and the water is flowing and I really should've given more thought. I was lazy since I could be here. Anyway, I said that it was maybe 4k or a little more. It was 5800. That's a good ways off. Granted I would've been more calculated as usual if we were getting out there, but still I was real off. He was good for 9900 here he told me. I don't like being that wrong even if I was quick to look and answer.
 

limbcontrol

New member
Thats why I enjoy the new technology of digital readouts on our remote. Its telling us the percentage of capacity. Our first brush pick we always pick smaller and call it our "test pick" and go off those numbers to see how much bigger we can go. Same thing when we get to trunk wood. 50% under cap is what we estimate for our test picks, after that its increased based off our initial test readouts. We aim 70-80% on all picks there after if landing zone permits. Not from a log chart or what we think it weighs. I really dont pay much mind to actual weight since thats a guessing game that as Mark mentioned above can be easily guessed wrong. Did I mention I love my remote control?
 

treevet

Branched out member
Location
Cincinnati, Ohio
Mark, I am surprised you guys are "yelling"...No comm sets? Tisk tisk.

The bottom line is that EVERY pick is a guessing game...on the weight of the pick side, not the cap. side. But obviously if you find you are well under cap. on the LMI AFTER the cut, then if the ensuing pick nearby is noticeably visually smaller...you usually can bypass the calculations on both sides, and who doesn't do that? . If you don't, you are wasting so much time...and time is money.

Day before yesterday, a 100' plus 40 plus dbh Eng. elm over a roof. I do a LOT of hanging limbs on a 17k cap. dyneema lanyard and then pick up the butt and release the lanyard . This saves SO much time hitching up the tops and lets you cut trees beyond reach , eliminates the foliage weight from the big wood picks and eliminates shock load on the crano (and you don't have to climb out of the bucket so much on biggies). My bucket is 75' reach. We do these every couple of days in VERY tight quarters...

Little scary blowing a leader out right into the roof space but when the lanyard engages.....


DSCF2186.JPG DSCF2193.JPG DSCF2197.JPG
 
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treevet

Branched out member
Location
Cincinnati, Ohio
Yes, it takes the tension off the hook up (with a second choker) and either un leash the girth hitch or untie the r. bowline first and then recover the lanyard for the next hook up. I usually have 3 in my bucket but ALWAYS have one.
 

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