Grove AT635E

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  • #676
You know a funny thing about standing up leads like that, often times right at the end of the lift when the piece is vertical you can see zero load on the crane. Now think about that, we have put a notch in top of lead, fat notch obviously and undercut it and lifted so bent all of those hinge fibers 90 degrees but they will still support thousands of pounds. Best not to over think stuff when you are doing it, we just know from experience that it works. Problem with crane work is mistakes tend to be big.....


We are constantly pushing the envelope with tiny baby steps:D
 
Yup. I think it was TreeTx Nate that once said that you never know exactly where that fine line is until you cross it.
 
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  • #678
Spent most of my life crashing bicycles and motor bikes of all forms.Driving cars too fast. Im familiar with the dance but really don't want to pay the piper with the crane. Scares the shit out of me thinking of some of the consequences of flipping the crane.

I love my crane and want her to live a long and trouble free life:)
 
Paul, can you lift something of known weight, like a machine? This can help test you lmi for accuracy.

A nickel weighs 5 grams. You can rest a, cough cough, postage scale this way, in college.

Your wheel loader might be marked.
 
Gotta push it. Also need to learn when to say no. I've gotten away with what most would call stupid shit many times but it was all calculated and I knew it would would withcthe given variables. My boss forced us to back out of a crane pick like that once. The crane op and I were both confident, but he signs the checks. Really sucked as I had to butt hitch the lead and then set chokers. The real kicker is we were with in the chart anyhow. Good work Paul.
 
Badass man, that takes some balls. If you aren't sure if your lmi is reading correct, call the outfit that does your inspections for you, they should easily take care of it or point you in the right direction. I'm clueless on crane assisted tree removals, but I'm fairly experienced in crane work. If the piece is 1700, you are good for 2400, but your rigging (chokers, headache ball) had to be added to that load weight as well. That puts the pick squarely into critical lift limits (75% capacity or more), plus potential shock loading or swinging too. Once again I know nothing of tree work and cranes, but to me personally, a calibrated lmi is vitally important when you are approaching critical lifts and pushing the envelope like that. I might be in the wrong here, and once again I'm definitely not critiquing anything, because I'm uneducated wholly in cranes/trees, but with the consequences so high, I would make sure that the lmi is on point. It would seem to me that since there is a dynamic element in just about any tree pick, and you can't put it back instantly if it's too much (unlike some construction picks), keeping under that 75% limit is a good practice. I almost had a 30 ton hydraulic crane flip over on me once (outriggers sank into asphalt despite pads), it literally happens so fast you don't have time to shit yourself.
 
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  • #684
Kyle my crane is 22 years old. I know how to adjust the feedback from the pressure transducers that the lmi uses to calculate the load and have done so with my stump grinder that weighs 4400. However it seems the second you get it dialed in it changes. I feel it always over reads by a good bit which adds to our safety margin. It used to bother me and I spent a good bit on some wireless load cells that would send a reading to the cab of actual weight however it didn't seem that helpful. If the lmi thinks it's overloaded the crane shuts down certain functions ,that is the pain and I have never had that with an airial lift(many times with but logs). After a while you get a feel for how the crane responds to loads and use that to calculate future picks.

To many this response is probably terrifying, guess work! However that is the nature of tree work and the reason most crane ops hate tree work. In the first vid I posted my biggest fear was the poplar top we were using to rope to would break out which is why I swung Robby out of there so quick. I guessed it would hold and prepared for the worst.

I should add that for at least a year we strived to keep all of our picks within 50% of our limit, i.e. we treated 50% as our tipping load.
 
I haven't met any crane ops that say that they hate tree work. They must not come to jobs. All the crane ops that I've met at work seem quite easy going about it. Nobody is ever reticent about discussing anything before a pick, but sometimes I seem to detect a slight yeah yeah yeah look in their eyes, I mean the pros. I like to ask them sometimes if they've seen many saws get stuck lately. Pretty much it's always a yes. They get called in to work with some iffy people at times, especially since the Pine infestation is offering removal opportunities to people who don't specialize in tree work. I've not heard of anyone refusing to do the work with their crane. I imagine that dealing with stuck saws and not much prepared people must be a nuisance sometimes.

Kyle, crane ops that came into that line of work doing trees before computers were installed, don't much need them. At least that's the impression that veterans give here, and when they have the computers shut off. Lift capacity at a certain extension and angle sure seems like a helpful feature though.
 
I guess once you've done tree work with a crane for a while it becomes second nature. Myself I never wanted any parts of it, to many variables. Calculating the weight of steel and concrete is a no brainer. Once you hook up to something already in the air and cut it loose you're committed, no second chance to recalculate. The technology doesn't exist to produce the sedatives I would require to become accustomed to the stress.
 
Some guys who have the knack along with many years experience, they are just wizards. They make the pick behave as if by telepathy. They land ridiculous picks in spots they basically cannot fit. And they know trees and wood weights and on and on. They make a crane into a miracle machine. The best I ever worked with was Big Ray, he weighed 425lbs and was super easy going and made it all look easy.
 
There are good operators out there, for sure! But on the other hand, the terrible ones can make things ... terrible!
 
I had the honor of working with Earl Keefer years ago, John Grove's number two man, literally, Earls clock number was #2. He was working for John before they were making cranes, building farm wagons. Carried a picture of the very first crane him and John built in his wallet. We were replacing a turntable bearing and boom pivot pin boss on a 55 ton once, neither were wore out, the welds failed. I told Earl the same guy must have made the same welds and laughed. Earl told me to fire it up, run the outriggers out and jack it up. Came down out of the cab and he was standing at the rear. He said come here boy and look at these outrigger beams and boxes, they were damn near "U" shaped. I'm like wtf Earl. He said this crane has been worked its whole life off the chart and that the welds didn't fail from normal use but from abuse. You NEVER depend on the stability of the crane to determine the load limit, you depend on the chart. Said he had inspected many a crane for insurance companies that had went over or had a structural failure and the first thing you determine is the weight of the load and boom angle. It doesn't take a genius to figure out who is at fault. What he was telling me was stay on the chart, that doesn't mean there will never be a failure but if there is it won't be your fault. I was a pain in the ass as a operator, had to know what everything weighed, the distance from center of rotation to the hook, ground conditions, on and on. Yeah I was a dick but I never had a pick go south. Take a look on YouTube of crane accidents, there's plenty. I don't think I could live with myself if I caused somebody to die or worse live the rest of their life a cripple.
 
I guess the points I was trying to make were this:

1. I know nothing of cranes and tree work, so therefore please ignore everything I say. I'm only saying this because I like you, and I'm repeating what I've been taught by people who actually know rigging and cranes. Several operators with decades of seat time running heavy lift crawler lattice booms, to decades of hydraulic crane operation. Riggers that are actually being asked by the international union to write training books on rigging. And other guys with decades of experience building large powerplants, foreman of rigging crews where tuggers are used to make cranes from the building frame to lift and drift pipes weighing tens of thousands of pounds. None of this is my info, this is what they made me learn.

2. The weight of the rigging has to be subtracted from the capacity. If the chart says you are good for 3000, but you have a 400 headache ball and 100 pounds of chain hanging, you can only lift 2500.

3. Making picks at 75% capacity or more is considered a critical lift. In construction, you cannot even attempt a critical lift without having a written pick plan, oftentimes reviewed by an engineer. Now tree work is obviously different, but picking that much is literally living on the edge. If anything goes wrong whatsoever, the crane is likely to tip or damage itself. If an outrigger has settled slightly or bleed down, if you aren't perfectly level, if the gibs are worn past spec (allowing the boom to deflect more than the angle finder is reading), if the slew bearing is showing its age, etc, you are in the red. Will the crane fail on that pick, probably no. But crane work is if you mess up once in 40 years you are remembered as that guy (hopefully still around). I guess what I'm trying to say is that per my experience and training, cranes are not meant to be pushed that far. Stay at 50%, make a few more picks, everything will last longer and be safer.

4. If you ever see a construction job where they are building a new building, and are setting steel (I beams, structural fabrications, etc), most times you will see them using an old school lattice boom crane. Sometimes it's for the reach, sometimes it's for pile driving or setting precast concrete sections, but usually it's there because setting steel is considered "duty cycle" work. They are setting one beam after another, all day, and production is a factor in everyone's mind (this is what tree work is like in my mind). This all day repetitive use is very hard on crane itself, so much so that it is worth it to them to bring another hydraulic crane out there to set up the lattice boom, and the associated trucking costs (multiple semi loads). The lattice boom is superior to the hydraulic crane in every way expect mobility and the ability to boom in or out for very tight spots (that should never happen in regular use, booming in or out under load is very hard on the gibs). Even though the sections of I beam are wayyyyyyyyyy under the capacity of the crane, the speed in which they are moved and the continuous movement makes it worthwhile to spend the time and money to set up a crane that can handle the abuse. Obviously a lattice boom is useless for tree work, but the duty cycle factor is enough reason alone to ease up on the pick size.

5. One more time, I know nothing of cranes and trees, but in good conscience I felt compelled to say something. If I was doing something you thought might be getting dangerous, I hope you would say something too. I could be, and probably am, overthinking this, but I feel better about it now lol. I like you, I wish you the best success, I only was speaking up because I want you to succeed and go home at the end of the day.
 
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  • #694
Kyle, thanks for your concerns. I do know how to calculate critical picks however as previously stated tree work is a guessing game..
 
I was more comfortable removing and replacing a 28 ton counterweight on a UH801 Hitachi shovel with a 30 ton Grove than I was with most half ton picks I made with a 55 ton Grove. Everything depended on the situation at the time.
 
Kyle that was very interesting re the use of lattice booms, thanks.
 
Wind places a side load in cranes, hence the problem. Hydraulics are never stored in the upright position, tower cranes have a wind vane to limit stress, but lattice booms are often left up in busy areas. Probably the best reference for any technical questions beyond that is Shapiro's aptly named "cranes and derricks" which goes into everything from configurations, designs, and forces (it's an engineering text). Did you have a specific question in mind?
 
What Kyle said. There is no wide flat area for the winds to push heavily on. I was only around one once. The op referred to it as a cable crane( cables control the structure ). They're not as common anymore.
 
Oh they are very common still, they just use them when it's advantageous, as opposed to everything because that's all there is. Hydraulics have come a long way, and are more mobile so therefore cheaper to use if you don't need it for a long time or large lifts. But lattice booms are still vastly superior and if they can justify it, they will use one. Peoria just got one moved that was set up for about a year, sister crane to big blue (Milwaukee accident). I think they said it's one of the top 5 biggest in the country, thing was super cool. You could see it from like 5 miles away lol. They had room to lay it down at the end of the day, forgot how much counterweight, it was kinda unfathomable. I should hit up some friends that were there and see if they got pictures...

And I found one, it had over 6 million pounds for counterweight...

PH-222009997.jpg
 
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