Jump to content

Log in or register to remove this advert

Rigging ropes and pulleys


Sciadopitys
 Share

Recommended Posts

I think most pulleys will take one size up in split tails. This is plenty to give the extra strength required at the anchor point. Squeezing a 19mm split tail into a 16mm pulley is not going to weaken it and certain not by more than you have gained in moving up from a 16mm anyway.

Link to comment
Share on other sites

Log in or register to remove this advert

  • Replies 33
  • Created
  • Last Reply

Top Posters In This Topic

Do you think there is a potential problem with using the larger Split tale with the pulley ?

 

Maybe

 

I once wrecked a isc blue pulley by using a green 2t webbing sling to anchor it. Was hard to close the pulley and big lumps were dropped into it. Didn't seem right after so was put to one side. On the next loler assesment the chap said that the bearing had collapsed. I am not sure whether it was using a sling to big for the design or wether it was the size of the lumps I dropper into it.

Link to comment
Share on other sites

Cheers Bob we have a blue 19mm. The green really only comes out when the blue is to short to get enough tucks on the timber hitch.

 

Do you think there is a potential problem with using the larger Split tale with the pulley ?

 

Yes i do although i obviously do not know what pulley it is

most of the cast pulleys we use tend to have a 20mm bushing but certainly having to force anything in will not help especially as when you load it the split tail will actually flatten and even put more force on the sides

Link to comment
Share on other sites

Time to move out of the dark ages and get myself a lowering pulley (use 16mm double esterlon) as I've recently been alerted to the dangers of the tight bending radius of lowering through a crab.

 

Would like the smallest, lightest pulley that will do the job. What would that be? ISC medium?

 

Also, is it safe securing it with a 30kn webbing strop, or should I be using something beefier?

 

We don't tend to rig down 200ft Wellingtonias too often, so I don't want to over-spec the job.

Link to comment
Share on other sites

 

Also, is it safe securing it with a 30kn webbing strop, or should I be using something beefier?

 

 

I'd say no since the 30kn will be the breaking strain and therefore your SWL on that sling would be 4.2 kn which is a little low for even small jobs. Having said that in the beech dismantle vid I posted recently I am using exactly that:001_tongue: TBH though that pulley and sling are normally used as a redirect or for light work such as that beech, really though I should have changed to the large pulley for the bigger stuff. The other problem with a webbing sling is its difficult to adjust on a single stem when blocking down so a proper round spliced split tail would be better. then it can be timber hitched or cow hitched to suit.:001_smile:

Link to comment
Share on other sites

The really bad thing is I can't remember the makes, I'm pretty sure they're both ISC. I have a small red swing cheek one which is the one in the Beech vid and a larger blue one which has a (i think) 24mm split tail. The blue one is sort of visible in the pine dismantle video from a while back. They're pretty common.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share


  •  

  • Featured Adverts

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.