flying_kiwiman
Hooked on the Buzz
Reged: 08/07/03
Posts: 300
Loc: Utrecht, Holland sometimes Dun...
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On some pulley's they only give you a MBS ( max breaking strength )rating . Is there a standard factor you can use to work out the WLL ( work load limit )??.
On the ISC pulley's the give a factor 5 ( WLL 2000kg, saftey factor x5 ). Does this apply for all pulley's?? What factor do you use to work out the WLL if you only have the MBS??
cheers Jelte
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MARK_CHISHOLM
TreeBuzzian
Reged: 06/02/01
Posts: 6563
Loc: HOME OF THE NEW JERSEY DEVILS
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That's a good point. The problem I've also seen is that some will give a WLL of 5/1 but don't also split that in half. What I mean is, I like how some co.s like Petzl who will mark each side with a WLL. For example, the little Fixe is labeled for 11KN each side, or 22 KN total.
I think that it is pretty standard to have a 5/1 safety factor over minimum breaking strengths for hardware.
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"In matters of style, swim with the current; in matters of principle, stand like a rock." TJ
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flying_kiwiman
Hooked on the Buzz
Reged: 08/07/03
Posts: 300
Loc: Utrecht, Holland sometimes Dun...
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Yesterday i did a pulling test on a CMI swingcheek pulley with a MBS rating of 71kn ( there was no WLL rating on this pulley ).
At 1200kg there was no sign of any stress or deforming. I went a little further and pulled until 2800kg. At this point the pulley was not looking so good...:)
The cheek's of the pulley were starting to bend outwards at the point where it was attached to the carabiner, also the wheel in the pulley was slightly pulled diagonally.
So i guess the 5/1 ratio is quite correct, in this case it would be about 1400kg
( which i exceeded ).
anyway, that pulley be f@*ked!!
happy rigging, jelte
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NickfromWI
Outta Control
Reged: 09/19/02
Posts: 3442
Loc: Los Angeles, CA
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Jelte, let's see some pictures of the messed up pulley!
love
nick
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Call or email for a splicing consultation! nick@splicesbynick.com 323-384-7770
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NickfromWI
Outta Control
Reged: 09/19/02
Posts: 3442
Loc: Los Angeles, CA
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Some manufacturers use differect SWLs. I've seen everything from 2:1 to 20:1. I wish manufacturers would just give us the MBS and let us decide.
love
nick
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Call or email for a splicing consultation! nick@splicesbynick.com 323-384-7770
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AxeKnot
Buzzin' Hard
Reged: 10/16/06
Posts: 705
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Safety Factors
I use 10:1 for rigging equipment
and 5: 1 for climbing equipment
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Norm_Hall
True Buzzer
Reged: 08/31/04
Posts: 2523
Loc: Wauconda, (Chicago),IL,USA
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Quote:
Safety Factors
I use 10:1 for rigging equipment
and 5: 1 for climbing equipment
I use the reverse. 10:1 for life support and 5-7:1 for rigging.
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Mahk_Adams
Official TreeBuzz Archivist
Reged: 01/24/02
Posts: 1501
Loc: Bloomington, Indiana
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Quote:
Quote:
Safety Factors
I use 10:1 for rigging equipment
and 5: 1 for climbing equipment
I use the reverse. 10:1 for life support and 5-7:1 for rigging.
Norm's is the norm.
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"Speak not to offend and listen without being offended." C.B.
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