Swing Cheek Re-direct negative forces

[Carl1991]

That will be fine just get rid of the tape sling. As above, climbing line, bowline end with crab then timber hitched to stem, then id lose the extra setup the closer in you get, as the swing shouldn't be that much if the stems roughly follow the pic

 

 

[TIMON]

Find out the MBS of the weakest component in your system, divide it by 11, that will give you your ‘safe working load’. for the size/weight of the peice. As others have mentioned it’s best to leave out the tape sling. To convert KN to KG simply add 2x zero’s.

[Joe Newton]

1 minute ago, TIMON said:

Find out the MBS of the weakest component in your system, divide it by 11, that will give you your ‘safe working load’. for the size/weight of the peice. As others have mentioned it’s best to leave out the tape sling. To convert KN to KG simply add 2x zero’s.

Is a safety factor of 10 not sufficient?

[carlos]

to the op. can you not move the main block high enough in the tree to enable the pieces to be top tied thus enabeling the swing cheek pulley to just stop or slow the swing? it would obviously require a second rope.

[TIMON]

Is a safety factor of 10 not sufficient?

IIRC a s/factor of ~ 11 is given for blocking down. Least it is on CS 41.
I think it is in the rigging research as well.

[carlos]

9 minutes ago, TIMON said:

 

IIRC a s/factor of ~ 11 is given for blocking down. Least it is on CS 41.
I think it is in the rigging research as well.

 

it is very hard to calculate the weight/load of the piece being lowered though.

[stihlmadasever]

Havent seen a log weight chart since my sectional felling course...

An experienced climber will know what size of chogs to knock off

[john meehan]

to the op. can you not move the main block high enough in the tree to enable the pieces to be top tied thus enabeling the swing cheek pulley to just stop or slow the swing? it would obviously require a second rope.

I was just going suggest that. Definitely what I would. This really decrease the shock load to the system and really is a much smoother way of doing things.

Also for the higher up pieces if you tied them around the balance point you could just use your original anchor as they would have room to run.

Good luck man

[TTownsend]

Ended up using a old bit of climbing line as a deadeye sling with the swing cheek pulley. Worked really well and kept the pieces a sensible size and everything ran smoothly.

Thanks everyone for the advice!

[Sambo]

On ‎10‎/‎07‎/‎2018 at 19:28, TTownsend said:

 

Can a Swing cheek pulley be used in this setup ? Currently taking down a large multi stem Norway Maple and need to stop the swing as it’s surrounding by static homes.

 

An x-ring would be just what I would need but sadly haven’t got one to hand so trying to make do. I understand swing cheek pulleys weren’t designed to take negative force/blocking but is it okay in this situation as it’s used to more to eliminate the swing and impact block will take most the weight.

 

Cheers

 

 

Pretty standard setup as far as my experience goes. The angle of the rope from the centre pulley to your redirect and the amount of rope in the system can help to dissipate some of the dynamic loading when a block is dropped.