Manual Winch for electrics - looking for reference documents

fredthe

Active Member
Many of the schools in my area use manual hand-crank winches (similar to http://jeamar.com/hand-winches/gw-wall-mount) for the on-stage electrics. My understanding is that these type of winches should never be used for this application, but I'm looking for specific reference for this. Just the ANSI standard for rigging not listing this isn't enough, I need something documenting that their use is prohibited (or at least a really bad idea).

Background: One of these winched failed recently, causing the electric to drop rapidly to the stage. The answer from the county maintenance department is to replace it with a higher capacity winch. I *really* don't want them to do that.
 
Many of the schools in my area use manual hand-crank winches (similar to http://jeamar.com/hand-winches/gw-wall-mount) for the on-stage electrics. My understanding is that these type of winches should never be used for this application, but I'm looking for specific reference for this. Just the ANSI standard for rigging not listing this isn't enough, I need something documenting that their use is prohibited (or at least a really bad idea). Background: One of these winched failed recently, causing the electric to drop rapidly to the stage. The answer from the county maintenance department is to replace it with a higher capacity winch. I *really* don't want them to do that.

We used to use hand winches at a facility years ago and used a secondary brake to lock off the load. May not be the answer you are looking for, but it might help.

http://www.tractel.com/us/pdf/BS_Technical_Sheet.pdf
 
For the simple reason that there are no stops that prevent jamming or unwinding completely I won't use hand winches for overhead lifting. Nich makes a good point - ask the manufacturer if they are suitable for overhead lifting - and get that in writing. The short answer is they should all be replaced with something designed and warranted for overhead lifting.

I'm presuming that these are clewed sets as well, so there is no single point failure safe when there easily could be.

BTW, what failed? Pleas help us all understand better the weaknesses.
 
It's a good thought, but wouldn't have helped in this case... it failed while the load was moving.

I'm also curious as to what failed. The brake? The cable snapping cause of the load? The worm snapping?

Also which model was it and what was loaded on the electric?
 
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This is from the catalog of the chain hoist manual linked above. There are very few products that manufacturer's recommend for overhead lifting applications. There are very few places outside of a stage where lifting overheads is even tolerated. Sorry to be a stick in the mud but s batten full of lighting over heads is serious stuff with big hazard potential. If you haven't read all of the product literature and don't understand the mechanics and the laws and regulations and standards governing overhead lifting, don't do it.
 
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This is from the catalog of the chain hoist manual linked above. There are very few products that manufacturer's recommend for overhead lifting applications. There are very few places outside of a stage where lifting overheads is even tolerated. Sorry to be a stick in the mud but s batten full of lighting over heads is serious stuff with big hazard potential. If you haven't read all of the product literature and don't understand the mechanics and the laws and regulations and standards governing overhead lifting, don't do it.

Thanks for digging. I've seen some people use that TYPE of product for lifting truss, but not that specific brand. So either they're also doing it wrong, or the other product(s) are rated for lifting.
 
Thank you all for the replies. It appears that the failure was due to wear, I suspect it was the brake mechanism was what failed, but there was also excessive play in the shaft that is driven by the winch handle which may have contributed. The handle spun rapidly as the electric descended. The electric was likely loaded near, but below, the rated capacity of the winch. I asked Jeamar (through their website) if they had any winches designed for theatrical use, and received no reply. It appears the Thern winch is the ONLY hand winch of this style that would be appropriate for stage use/overhead lifting, and I have forwarded the info to the responsible parties.

As for finding the applicable standards (which was what I was looking for initially) what I found was:

OSHA Simplifies Documentation on Overhead Lifting
http://www.plsn.com/news/21-news/8021-osha-simplifies-documentation-on-overhead-lifting.html

And the relevant OSHA regulation:
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9830

Key paragraphs from the regulation:

1910.179(f)(1)(i)
Each independent hoisting unit of a crane shall be equipped with at least one self-setting brake, hereafter referred to as a holding brake, applied directly to the motor shaft or some part of the gear train.

1910.179(f)(1)(ii)
Each independent hoisting unit of a crane, except worm-geared hoists, the angle of whose worm is such as to prevent the load from accelerating in the lowering direction shall, in addition to a holding brake, be equipped with control braking means to prevent overspeeding.

So, you need both a control brake and a holding brake, without that it's not going to be OSHA compliant. The Thern winch has both, the ones currently in use don't. This is pretty close to what I was looking for, as it's a regulation that would disallow the use of (most) hand winches. Unfortunately they were very common to use in the 1970's and 1980's, and convincing the school system to replace all of them is going to be a tough sell. But at least now we have the combination of a failure, the regulations, and a reasonable replacement to push the issue. If your stage has a similar setup, learn from this and act now!

-Fred
 
For those that asked, this was a Jeamar model WG, marked with a SWL of 2200 lbs. Single cable from the winch, somehow connected to 5 lines from headblocks to the electric. The electric itself was fairly standard, double pipe, with about 10 8" fresnels, a couple of lekos, and two movers that sacrificed themselves to save the rest of the instruments (i.e. they hit the floor first.)

Oh, and for those who really want to get mad at unqualified people doing rigging, the county maintenance department initially just wanted to repair the winch and put it back into service. :eek:
 
Where does OSHA permit a crane lifting overheads? I believe you will find it specifically prohibits people under lifting loads. Google does not an expert rigger make.

FWIW I did stupid things - rode arbors and battens, made scenery with asbestos furnace cement and fibreglass in inadequately vented (unvented) spaces - and thought I knew more than I did - so be really smart and learn from the experiences of others.
 
Where does OSHA permit a crane lifting overheads?
The reference comes from the PLSN article which references the OSHA standards for overhead and gantry cranes as being the closest to cover theatrical rigging, and the referenced regulation makes no mention of people under the loads.

I was looking for regulations/standards that covered this situation, and this was the closest I could find. Is there something else that would cover this from a regulatory standpoint? PLASA/ANSI to the best of my knowledge covers counterweight or powered hoist systems, but is there anything stating that these are the *only* systems allowed to be used a theater, in which case even the Thern winch (which an outside rigging company has already recommended to the school) isn't allowed. If the only solution is counterweight or powered, the county's solution could easily be to convert to dead hung... which really isn't a desired result and has it's own issues.

If you can point me to additional specific regulations, that would be useful.

Oh and I never claimed to be an expert rigger, which is why I'm asking these questions... if for no other reason than to provide ammunition to use to push the county into consulting those properly qualified (which doesn't include their own personnel).
 
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I'm a little out of touch with them and I would need to reread the PLASA standards but I believe both are for overhead lifting by the subject, though neither are statutory standards to best of my knowledge. Neither seem to cover manual winches either.

That leaves Thern, and I'd want a written statement from them about overhead lifting applications. I suspect you would get it.

If you remain stuck, I'll check my sources at Thern later this week.
 
Looks like Sapsis rigging also sells them for theatre. They may just be badge engineering Thern's equipment though, not sure from the photos.
http://www.sapsis-rigging.com/Merch...&Product_Code=07-11-CW-0002&Category_Code=320

It looks to me like one of the key features is
A load holding lockout pin secures the drum to the frame for secondary load holding

reading the literature on this style winch it is apparent that the winch itself cannot be relied on to hold the load. or rather no manufacturer is willing to have the winch the only support of something hanging overhead. some sort of secondary load holding arrangement is necessary.
I have two of this style winch in my small space. So i will be looking to provide some sort of load holding that does not involve the winch. as there was no provision made for such in the original install some 30 years ago.

none of this answers the question of why did the OP winch fail when in motion.
 
So proper operation requires that there be no one under the load while its being lifted or lowered and without load pin in place.

If its a clewed set, consider a chain from the clew to a tie off on the wall or floor or hand winch. Easy to install but some effort if usedca lot.
 

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