Arborist lifting from 2 part block?

[basspro]

hey all I’m doing trees with a Liebherr ltm1095. It only has shy of 13k line pull. So we are leaving it 2 parted with the block on. The climber is tying off to the hook itself and his 2nd tieoff is on the reliefs on the block itself, with no way of coming out. It has been asked if that is legit. There are 2 welded bars at the top of the block that would prevent the block from falling if the seave disentegrates. Is this a legit or approved way of flying the climber?

 

[crane operator]

A picture of the block would help. Why would you need more than 13k in tree work? Have them cut smaller pieces .

Just to be clear- you fly the climber up in, he ties off in the tree, and you attach to what he's cutting off? And he wants/ needs two different tie off points on the hook/ block. On ball he's tying to the hook and then above the becket around the cable, and you're wondering what to do with block in that is similar?

If you want to keep the 2 part in, I'm not sure what else he's going to hook too, aside from the hook. Honest- you will know more about cranes than the osha man (if he shows up), but you aren't going to find it as a "approved" tie off point in the liebherr book.

 

[Tugger2]

I agree with you crane operator on the single part line for tree work , working with the single line keeps your lift plan more conservative especially at longer reaches .This being said i know the load chart tells you exactly what you should be lifting at a given radius with x number of parts but tree work isnt an exact science when it comes to irregular shaped trees covered in branches. Its easy to figure the weight of a nice straight 100' fir compared to a gnarly old oak or arbutus with 2' branches sticking out everywhere. In regards to a man basket on the 2 part block i done it for years pile driving on barges as that drum on the machine always had the power lowering on it as required. My 2 blocks all have odd number sheaves and a tailhold eye on the block for running 3 or 5 part. We just used that eye and never had any issues. Ive worked with hyd cranes where they would drop the block every time and go single part, they had quick reeve but still an extra move in the middle of things.Am i missing something deep in the regulations regarding personel lifting on two parts?Is there any recorded failures of a hook or becket during the lifting of personel, requiring this extra strap to run up to the becket?Two blocking or operator error is the worst failure i can imagine while lifting personel .

 

[crane operator]

All the liebherr hooks I've been around have the 3-5 part becket attachment in the center top, not on the side, so that would kind of eliminate it as a tie off point, too easy to get that tangled up.

 

[John Griffin]

Ansi Z133-17 is what covers arborist safe working practices. This is what osha uses as they do not have their own specific arborist rules. I'm an arborist with his own crane. We are now supposed to tie in to a wired shut shackle that is around the load line above the ball with a friction saver routed through it. I don't see this working on two parts of line.