Crane slings

hseII

Well-Known Member
The hook is designed to be loaded vertically. Side loading is not recommended. The ones to the outer edges would most likely be balancers so it really shouldn’t be an issue but if something were to go wrong that’s where big brother would look
This.


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Crimsonking

Well-Known Member
This is good info that I’ve never heard before. To be honest, I’ve never noticed lines on the hook. Now, don’t look at the team I worked with as cowboys- they are top notch arborists, but it’s interesting that they didn’t have this info. We’re always learning!
 

dbl612

Active Member
its best to keep the included angle of slings below 90 degrees. then there isno gate loading or hook derate.
 

CanadianStan

Well-Known Member
This is good info that I’ve never heard before. To be honest, I’ve never noticed lines on the hook. Now, don’t look at the team I worked with as cowboys- they are top notch arborists, but it’s interesting that they didn’t have this info. We’re always learning!
Same as in rigging principles, the wider you open your rope angle, the more you increase the forces - without actually changing the weight of the pick.

In the case of a crane pick you’re exerting more outward pull on the ring, and more diagonal inward pull on the tree branches themselves.

(I feel really borderline spydey after that last bit)

See the attached vector chart to get an idea of force multiplication

1542100127319.jpeg
 
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Crimsonking

Well-Known Member
Same as in rigging principles, the wider you open your rope angle, the more you increase the forces - without actually changing the weight of the pick.

In the case of a crane pick you’re exerting more outward pull on the ring, and more diagonal outward pull on the tree branches themselves.

(I feel really borderline spydey after that last big)

See the attached vector chart to get an idea of force multiplication

View attachment 55125
I don’t see how the chart applies to crane slings, since each sling is terminated at the branch and at the hook. There is no multiplication of force by pulling midline. I can see how it would relate to a branch, except there is always a central line tied straight downward, negating the forces against branch slings, which then become mostly stabilizers. That may be the thought behind the team’s practice, as they always emphasized the need for the central anchor. Sure, there is some load on the branches, meaning load on the hook- not denying that, but it is considerably less than it would be without a center, vertical leg.
 

Steve Connally

Well-Known Member
I’ve rigged tops with multiple balancers many many times and no central verticle leg. As those slings gain angles they gain them at the eye termination on the hook. Spread them out far enough and you crowd the gate and get critical angles on the hook.
 

Steve Connally

Well-Known Member
the purpose of the shackle or master ring is to eliminate side loading of the hook and keep forces in the bowl of the hook where they belong
Yes that's what I said although you said it much more clearly. Now I reread my own sentence, it makes zero sense. So just to clarify you can still have critical angles on a master ring or shackle.
 

Anthony Barren

New Member
Has anyone used or recommend the Morgan Thompson Crane Sling? The chain with the choking hook, or are round slings the best way to go. I’m a new TreeMek owner and know I’m going to need a sling(s) of some kind for trunk picks. I see use of the round slings and never of the chain style, however, the chain style seems like it could be beneficial with its adjustability feature, I unfortunately don’t have the experience with either. Thank you.
 

Fivepoints

Well-Known Member
Has anyone used or recommend the Morgan Thompson Crane Sling? The chain with the choking hook, or are round slings the best way to go. I’m a new TreeMek owner and know I’m going to need a sling(s) of some kind for trunk picks. I see use of the round slings and never of the chain style, however, the chain style seems like it could be beneficial with its adjustability feature, I unfortunately don’t have the experience with either. Thank you.
I'm a really big fan of round slings. One reason is they are hard to use wrong. You can have someone put slings on that doesn't have a lot of experience. If they can rappel using an 8, they can be taught to put slings on in a few minutes. We regularly use two or three at a time to balance out picks. You can adjust them by sliding the choke up,or down as well as taking additional wraps.
 

deevo

Well-Known Member
Has anyone used or recommend the Morgan Thompson Crane Sling? The chain with the choking hook, or are round slings the best way to go. I’m a new TreeMek owner and know I’m going to need a sling(s) of some kind for trunk picks. I see use of the round slings and never of the chain style, however, the chain style seems like it could be beneficial with its adjustability feature, I unfortunately don’t have the experience with either. Thank you.
Stick with round slings for trunk picks, some like chains some don’t, @Steve Connally can post some pics with his and the hooks he uses on his round slings for setting and adjusting them easier.
 

Steve Connally

Well-Known Member
Round slings are great for log pics but there are much better options for balanced pics. Round slings aren't in my choice matrix for a multi sling pic unless its trunk wood. Adjustability is inferior to a good dead eye sling. I use sling hooks and believe me, if there is a way to use a round sling incorrectly, I've seen it. Shackles are nearly (NEARLY) idiot proof but a complete pain. The sling hooks are idiot proof but even less idiot proof than the shackles. Some guys have a tough time trying to figure out how to set them without loading the gate. I think I'd like the Quantum X material with a gunnebo hook spliced on the end of it and married to a steel ring at the hook for log pics. I just cant afford the splicing at this point. Gonna wait until I wear out the round slings.

I ordered the Gunnebo GrabIQ slings. Double sling with 25' of chain and these crazy hooks that lock under tension. @pctree uses them. I have 4 lengths of round slings for log pics with the fly jib. More for if the jib comes off. By having the GrabIQ I can eliminated all 4 sets. The climber can adjust the length at the hook. I also ordered 2 MidGrabIQ for the rare occasion its easier to take some links out of the system.

My thoughts......Chains are so heavy blah blah blah. 5/16 chain and entire set up with hooks is less than 75lbs. I'm the only one who actually has to pick them up to put them on the hook. Amazingly the crane doesn't mind lifting heavy stuff. It's kinda cooky how that works. It's one leg not 2 so less tangle or for a double sling its 2 legs instead of 4. I love the sling hooks I have, but throwing them around a trunk is a pain. The chain will be easier. The chain hooks are made to lock on tension. Hard to load them wrong. Slinging an ivy covered log? Round Slings are gonna slip. Chain is gonna dig in. For the climber rigging the material I believe the chains are and improvement. My chain set up is rated for what I can pick with the fly jib. 9300lbs is 100%. I wont exceed than with the jib on. When I take it off for massive logs I'll go back to round slings, big ones, and cut wedges for them to ride.

There have been 2 near misses in my area with round slings and the secret handshake method. I had a fairly straight 5 k log slung about 2 to 3 feet down the stem. Secret handshake method. Cut, lift, and getting ready to go over the house. I'm stowing the saw and hear the unmistakable sound of the hoist cable slapping the top of the stick crane boom. If you haven't heard it, try to never hear it. Its awful. I turned around and the log was sitting in the sand exactly where they had removed the above ground pool. 10' from the house. Another local guy who knows his stuff had a similar issue. This wood didn't have a ton of taper either. Just so happens we both were using the same crane company now they will only allow tree guys to use cable chokers. They would rather have an unbalanced sloppy pic than have something slip out. I have spent many hours trying to dissect the events leading up to dropping the log and I have no answers. I've consulted the guys who came up with the method and they have no answers. It's just one of those things. Luckily we didn't kill anybody or crush anything.

Needless to say there is not one single tool in the box for crane slings. I have a pile of stuff and rarely use most of it, however, it's there if I need it and at some point I will.

I'm excited to learn craning with the chain system and get feedback from the climbers. Paul has been using them since the caveman invented the forge. Actually Paul may be the caveman. He's kind of crafty with inventions. The chain system was $520. The 8 round slings at around $80 each is $640. The sling hooks are about $110 each. Fabric wears out quicker than grade 120 alloy chain. I had to replace the roller pins in the sling hook gates twice in 6 months. They take a beating. Shackles are less maintenance but try finding the perfect match pin sold without the body so you can have a backup when the climber drops it into the ivy bed and you don't have a metal detector.

Also keep in mind I have a knuckle boom so I don't have the headspace a stick has. That's why I need 4 different length slings. Sometimes if its a tall pic I need the 10' slings because I just cant get any higher. Low pics I need the 20' so I can keep my boom angle as close to 45/70 as possible. Plus what I pick up, I have to put down. Totally different beast.

So crane slings.........What are the best? Well, when?, In what configuration? What equipment are you lifting with? The answer is YES. all of the above, all the time, every one of them. You wouldn't do tree work with 1 saw? Why do crane work with 1 sling?

Just sayin.
 
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craneguy1

Well-Known Member
I would agree with steve... hard to have only one option...cable crane here, and i use cables for wood picks, unless a nylon eye and eye is easier for the climber and also won't slip off... in terms of cables, i literally have one for everyday of the week; including sunday on the truck at all times. 3 are different sizes with pass through thimbles, 4 are matched sets of 2 different diameters for "a" framing. My diameters run from 3/8" to 3/4"...cables bite well.
 

craneguy1

Well-Known Member
About 15 years ago i met with a master rigger at a large local supply house to discuss a wire cable setup that was like the ones used from our crane rental companies...which i also have. What i ended up with and use regularly are cables that have the same shaped thimble on each end. Each will pass through one another to form a choker...although i always use the one side with the proof tag on the hook, keeping it safe and also the cables last alot longer if only one end is used to form the choke.
 

climbhightree

Well-Known Member
Round slings are great for log pics but there are much better options for balanced pics. Round slings aren't in my choice matrix for a multi sling pic unless its trunk wood. Adjustability is inferior to a good dead eye sling. I use sling hooks and believe me, if there is a way to use a round sling incorrectly, I've seen it. Shackles are nearly (NEARLY) idiot proof but a complete pain. The sling hooks are idiot proof but even less idiot proof than the shackles. Some guys have a tough time trying to figure out how to set them without loading the gate. I think I'd like the Quantum X material with a gunnebo hook spliced on the end of it and married to a steel ring at the hook for log pics. I just cant afford the splicing at this point. Gonna wait until I wear out the round slings.

I ordered the Gunnebo GrabIQ slings. Double sling with 25' of chain and these crazy hooks that lock under tension. @pctree uses them. I have 4 lengths of round slings for log pics with the fly jib. More for if the jib comes off. By having the GrabIQ I can eliminated all 4 sets. .
Are you secret handshaking this setup...or just straight choking both sides of the spar/chain individually?

I like the looks and thought behind this system...make it easy and idiot proof.

Grrrr, and I just bought 2 endless eye slings last night at Gap Arborist (to finally get away from using eye to eye slings on trunk wood)
 
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