Crane removal techniques

[Toddppm]

Seein as how I never done a crane job as the climber I've got a couple questions for you guys. What is the jib /gib ??? Monkeypuzzle Are you saying your dad leaves his rope tied into the hook while it's taking a piece to wherever it's going ?? How long are your ropes???

 

[TheTreeSpyder]

Jib is extra extension nose for some cranes, allowing longer boom, allowing steeper angle on boom to hit same spot, allowing more weight to be handled more positively and with less shake during movement. The angle of the boom determines changing support capacity every time, next would be outrigger setting i would think, assuming proper strength/power in all else.

We use braided steel chokers provided by crane company and screw shackles. i tighten screw all they way and back off an 1/8th turn to prevent jamming. Good idea for groundy to have piece of rebar or something for tapping/vibrating stuck pin screw on shackle anyway. Pliers are a lil better, in case need to grip pin with leverage, but usually tapping is all that we need from time to time.

i wouldn't recommend riding with load on crane, too much can happen as it is taken, moved, swinging etc. especially pieces big enough you need seperate man to set connections. i'd imagine you have favorite company and operator that allows such things (trying hard to be nice!!).

 

[rbtree]

The jib is a lattice structured section that can be attached at the end of the hydraulicly operated boom sections. It reduces the load carrying capacity quite a bit, but certainly extends the reach.

Most of my craning is of 20-60 foot conifer trunk sections. Some crane operators dont allow riding the load line, even if I show them the Ansi guidelines. After choking the section, usually with steel, I rap down off the hook. I have the guys put my saw on the lifeline, which comes up to me, or close. Then, I start my cut directly below ( imagine a plumb bob) where the log is choked, and usually just make one cut straight through. As the operator lifts, the kerf automatically opens up. If this method is not practical, I will make two cuts, just barely mismatched, and overlapping.

 

[rbtree]

Another

 

[rbtree]

Takin her away...

This job was in Somerset, about 500 vertical feet above Seattle. That is downtown, Mercer Island, the East Channel Bridge, and the Olympic Mts in the background. Eye Candy, eh?!

Don't you all decide you want to move out here, now....!!

 

[treeclimber165]

In response to my question about what he does while someone else rigs for him-

Originally posted by monkeypuzzle
I just hang and keep a birds eye view of the ground work,and yes I do have to move about from time to time.What should I be doing?

I just cannot see the efficiency in this method. I would imagine that this would take more crane time for each setup (35 ton prices are $100 per hour here), not to mention wasting one man.

Every crane removal I have ever done was climbable, never had one I couldn't climb (yet). By keeping an extra sling with me, I can set up the next cut while the crane swings the last to the ground and unhooks. When I get the hook back, I only need to hook it and move back to my cut point. Probably takes me less time than your father rappelling to the ground and clearing his rope. But I should not criticize, as I haven't seen how you do it. And it must work for you, so that is what matters.


Nice pics, Rog! Is that an 18 ton with 60' of stick? We had one just like that at a local city I worked for, quite handy for most jobs. Only needed to call in a big one a couple times.

 

[John Paul Sanborn]

Only when the responsible person determins there is no other safe way to perform the task.

Will you find a crane company to go along with that?

 

[rbtree]

87 feet of boom, or total reach, I think it is, and only 17 tons. We pick some pretty heavy stuff, for sure. Mike charges 85 per hr, 2 hr min, 35 bucks travel, which is unheard of!! A regular crane co is 3 hr min (or 4), and at least 135 per hr for a 35 tonner.

 

[rbtree]

A close shave....?


....nah

 

[rbtree]

see.....

....I dont shave......

..much

 

[Toddppm]

Very cool pics!!!
Maybe someday I'll run into a job where they'll pay what I want and I can use a crane too, always seems like theres either too many wires or too far to access. Priced a job today to remove 4 Hemlocks + a Maple all only about 60 ft. or so in the backyard. I priced it well , don't know if I got it yet but seems like a pretty easy rigging job, didn't even consider a crane, need to get out of that mindset I guess.

How do they put the jib on anyway? I've always wondered how they put up those huge cranes like on top of highrises, do they use a smaller crane to assemble the big one? Or does it kind of assemble itself somehow

 

[rbtree]

todd,

60 feet into the backyard is quite a bit, if the crane cant get back there. That would take a pretty big crane. I recently found a 50 tonner with 166 feet of boom, that would work. cost is about $160 per hr. But with hemlock, there is little wood value compared to doug fir, which off sets our crane costs, and then some...

A mobile stick crane, with no hydraulics, only cable, has a fixed boom, and must be assembled with the help of another boom, I think. (Much like a tower crane) So setup/teardown runs minimum $1400. I've never used our local guy, who does trees all the time. They can pick 100 foot plus firs, from the backyard, whole!!! But, with 166 feet of boom, he needs the whole street to set up in, not too practical most of the time, I'd say.

 

[kf_tree]

rb, from your pics it looks like you guys get some great views from the tree tops.

 

[monkeypuzzle]

I never said he rides the load(piece of tree) back to the ground...It takes minimal time to place the sling(s) and get to the ground, and clear the rope,and yes that is the fun part for the ole fellow,at least he wants to be part of the action at 60yrs.On pines it is easier with just one climber but with these large H2O and Laurel oaks I find it hard for one climber to beat us.

 

[Kneejerk Bombas]

Now that I understand that he rapels down, it seems like an efficiant wat to do the removal. He gets lifted, does his thing, then rappels down before loading, it does sound fun.
I would be concerned if he routinely rode the peice because it opens up so many things that can go wrong.

Most of you probably saw the crane accident we had here in Milwaukee, while building the stadium. One crane failed, due to wind loads, and hit the second crane, with the manbasket.
Even with the best operators and the best equipment, things can go wrong.

 

[monkeypuzzle]

35 ton @ 100$ per hr. 3hr. min. here. There is a break when you pay cash,.....so if I use him for about 2hrs. it will cost me about 250-275$ plus his tip.

 

[Treeman14]

Originally posted by rbtree
The jib is a lattice structured section that can be attached at the end of the hydraulicly operated boom sections. It reduces the load carrying capacity quite a bit, but certainly extends the reach.

Au contrare, mon frere. The jib actually INCREASES lift capacity since the boom is at a higher angle.

Also, I didn't see any mention of a technique we routinely use for attaching the chokers to the cable. We shackle the choker above the ball so that after the piece is choked, the climber can be lowered on the ball to the cutting position. With a long choker, you've got almost 20 feet of lateral movement and infinite vertical movement. After the climber is unhooked from the ball, the cable is brought up and snugged.

 

[TheTreeSpyder]

Yo Mr. Tree Man;

i was about to post that i had been corrected; for i called 3 crane places that see it RB's way!!

i questioned pretty good on'em too! i directly asked if the jib let the boom be 10 degrees higher (and reach over same spot) wouldn't that capacity be better than lower boom without. Actually, i thought that it was going to come out that wee were both right, and that nearer horizontal, RB was write and that nearer vertical i was right; but all 3 said across the board that RB was.

They said it just put boom higher with loss of capacity, so i asked then why if you had enough boom would you put on jib? ; they said so it would be higher (Oh, that part slipped by me!!!). Then when there was enough clearance why did the operator insist on stopping and putting on jib? To make it higher..........

After getting off phone and trying to draw this in head, i can only imagine this would be for better stability of load from higher point of support or something. Now this is for hydralic cranes, putting lattice nose on solid boom, not cranes constructed on sight from 3 semi loads that are all laticed construction in the boom.

But, otherwise than this issue of lattice jib being so much lesser capacity than solid steel arm, the more vertical the boom the higher capacity the boom angle position, and the less leverage on outriggers anchoring the whole show too. So be as close as ya can and put the boom up, proper craning would also be to be over your load always i think. So if ya try an 18T rental (U operate) please, don't just put the boom up but not over load cuz some dum-me was talking about it on the freakin' inter-net!!!! Especially someone with screw loose calling'em self a tree spider and can't sp'ill write!

Brett (or anyone else) if ya have any sources on all this i think we would all like to know more.

Enquiring minds need to know!

 

[TheTreeSpyder]

This doesn't address the gib question, but very good at expressing the imperative of proper boom angle to load:

"The Boom Angle, Radius, Weight Factor

Any crane under load has some critical operating factors that have to be considered to ensure the whole outfit doesn't become unbalanced and tip over. These factors are boom angle, boom radius, and the weight of the intended load. If the weight of the load is a constant, then the only possible variables are the boom's angle and radius. However, changing any one of these two variables will not only affect the other, but could also cause the weight of a properly calculated safe load to change to an extremely unsafe load.

For instance, if the boom angle is decreased and the boom's radius increased, the maximum weight of the load has to be reduced. If the load weight is not reduced, a tipover is very likely. So, naturally, it's imperative the crane operator pay keen attention to this "weight/angle/radius" formula before the operation is started and especially during an actual lifting operation.

In this particular tipover incident, the mishap load was over 2,200 pounds more than the crane's boom angle and boom radius allowed by tech data. The difference in what the tech data called for and the mishap crane's actual boom angles and boom radii at the time of the mishap were 19° and 9 feet, respectively. Big differences, eh?

Supposedly, the criticality of this weight/angle/radius formula wasn't stressed or emphasized during the crane operator training course. The course lesson plan didn't even have an instructor's note to do so. So is it any wonder the base crane operators might not pay very close attention to this important factor during lifting operations?"

From body of article in:
http://safety.kirtland.af.mil/magazine/htdocs/julmag97/pg28jul.htm

 

[MasterBlaster]

I found this good thread, and I thought I would bump it.

I have allways just cut straight through, as I have stated in previous posts.

But several of you stated the merits of putting a backcut, or even an underbed.

I tried that out today, and I can see where it has its place.

Each cut is different, and requires individual approaches.

Smaller wood, up to 20", you can saw through with no problem.

Bigger, a back-kerf cut worked well for me. Even a shallow underbed. Just hold your hinge til the right moment.

See? I can change!