"For Overhead Lifting"

[Frank Koenig]

The "This looks so dangerous..." thread inspires me to ask a question that's bugged me for some time. Catalogs of rigging hardware have two categories of items: "for overhead lifting" and "not for overhead lifting". Components in both categories are provided with working load limits and, in some cases, ultimate limits. When I look at finished rigging assemblies, as might be provided for a particular model of speaker or general industrial use, they include components such as pins and long D-shackles that I cannot find as rated for overhead lifting in any catalog.

My guess is that engineering approval of the entire assembly, which will indeed be used to hang heavy stuff over peoples' heads, allows the incorporation of not-for-overhead-lifting components much as it allows the use of fabricated parts such as beams made from standard shapes, etc. The notion is that the engineer analyzed the components and deemed them suitable. Is this how it works?

And, while we're at it, what, exactly, is overhead lifting? Is it the temporary, dynamic lifting of objects over people, say what a gantry crane in a steel mill does, or does it apply to static installations (that EON hanging over the dive-bar bar) as well? Where is the line?

And before the rigging police go on the if-I-have-to-ask-I-should-hire-a-rigger tirade, I point out, defensively, that intellectual curiosity that exceeds one's credentials about a subject is neither illegal nor immoral. Even the gods of rigging had a brief moment in their lives when they possessed the knowledge but had not yet passed the exam

Thanks.

Best,

--Frank

 

[Tim McCulloch]

Re: "For Overhead Lifting"

The "This looks so dangerous..." thread inspires me to ask a question that's bugged me for some time. Catalogs of rigging hardware have two categories of items: "for overhead lifting" and "not for overhead lifting". Components in both categories are provided with working load limits and, in some cases, ultimate limits. When I look at finished rigging assemblies, as might be provided for a particular model of speaker or general industrial use, they include components such as pins and long D-shackles that I cannot find as rated for overhead lifting in any catalog.

My guess is that engineering approval of the entire assembly, which will indeed be used to hang heavy stuff over peoples' heads, allows the incorporation of not-for-overhead-lifting components much as it allows the use of fabricated parts such as beams made from standard shapes, etc. The notion is that the engineer analyzed the components and deemed them suitable. Is this how it works?

And, while we're at it, what, exactly, is overhead lifting? Is it the temporary, dynamic lifting of objects over people, say what a gantry crane in a steel mill does, or does it apply to static installations (that EON hanging over the dive-bar bar) as well? Where is the line?

And before the rigging police go on the if-I-have-to-ask-I-should-hire-a-rigger tirade, I point out, defensively, that intellectual curiosity that exceeds one's credentials about a subject is neither illegal nor immoral. Even the gods of rigging had a brief moment in their lives when they possessed the knowledge but had not yet passed the exam

Thanks.

Best,

--Frank

Rigging exams administered by Gravity don't have good outcomes.

You're right that in an engineered solution all components are evaluated for suitability and the RPE whose stamp is on the drawing is liable for the results of his/her design (presuming everything was sourced, built and installed per the drawing and accompanying specification documents).

 

[Brian jojade]

Re: "For Overhead Lifting"

The primary difference in stuff that is rated for overhead lifting is the traceability and testing of the items. Every piece of gear I have seen that is rated for overhead is marked in some way with a date, lot production number, etc. That way, if something goes wrong, the failed piece can be traced back to see if it was a manufacturing flaw, or if it was an installation error. Many items indicate that the actual item itself has been load tested at the factory as an added safety precaution. Obviously, these things cost $$, so rated for overhead lifting pieces are far more expensive.

You can be pretty sure that the Eon at the dive bar isn't using rated hardware for overhead lifting. Be happy if it at least looks to match what rated gear would be for.

 

[Rob Timmerman]

Re: "For Overhead Lifting"

The primary difference in stuff that is rated for overhead lifting is the traceability and testing of the items. Every piece of gear I have seen that is rated for overhead is marked in some way with a date, lot production number, etc. That way, if something goes wrong, the failed piece can be traced back to see if it was a manufacturing flaw, or if it was an installation error. Many items indicate that the actual item itself has been load tested at the factory as an added safety precaution. Obviously, these things cost $$, so rated for overhead lifting pieces are far more expensive.

You can be pretty sure that the Eon at the dive bar isn't using rated hardware for overhead lifting. Be happy if it at least looks to match what rated gear would be for.

Yep. In construction, where common materials are used, proof testing is usually conducted. For important things like foundations, this means that concrete samples are prepared from the same batch, and destructive testing is performed on the samples. In industrial establishments, cranes are load tested with a 100%-125% rated load weight. Additionally, inspection records are kept on file. All this is additional overhead that adds cost, but at the end of the day it's the difference between "this is probably safe" and "this is known to be safe because I can show that a representative sample has been tested"

 

[David Buckley]

Re: "For Overhead Lifting"

Rigging exams administered by Gravity don't have good outcomes.

That is a fabulous phrase. And so fecking true...

 

[Frank Koenig]

Re: "For Overhead Lifting"

You're right that in an engineered solution all components are evaluated for suitability and the RPE whose stamp is on the drawing is liable for the results of his/her design (presuming everything was sourced, built and installed per the drawing and accompanying specification documents).

Tim, thanks for the reply. I guess it's $10 for the hoist ring and $90 for the product liability premium.

As for what constitutes overhead lifting, It must be like porn: you can't define it but you know it when you see it.

Best,

-Frank

 

[Jordan Wolf]

Re: "For Overhead Lifting"

As for what constitutes overhead lifting, It must be like porn: you can't define it but you know it when you see it.

The company I work at considers anything suspended or supported above 6ft. off of the ground to be rigging. It's based off of the fall/fatality height thing, but I agree with it. It doesn't take much movement to make a component fail, and once one part goes, the rest usually follows.


Sent from my iPhone

 

[Jordan Lahr]

Re: "For Overhead Lifting"

As far as what constitutes "overhead" I've heard two things. 1 the rigging moves over someone's head during normal use. IE if a truss flys out during a song while the artist is on deck. Or the other way was anytime its suspended over someone's head. Example any speakers above an audience or lighting hung above the audience. I lean more towards the first definition than the latter

Sent from my XT1060

 

[Brian jojade]

Re: "For Overhead Lifting"

As far as what constitutes "overhead" I've heard two things. 1 the rigging moves over someone's head during normal use. IE if a truss flys out during a song while the artist is on deck. Or the other way was anytime its suspended over someone's head. Example any speakers above an audience or lighting hung above the audience. I lean more towards the first definition than the latter

Sent from my XT1060

Both are overhead, and in the event of a failure, there is risk of injury or death. Both must use extreme caution. With static loads, getting the product up there in the first place can use means that would not be considered acceptable if there was an audience below. However, it must be secured in place in a method approved for overhead lifting.

Stuff that is used for overhead movement is going to require far more safety bits and pieces than simply hooking up a hoist and moving it up and down.

 

[Jim McKeveny]

Re: "For Overhead Lifting"

Catalogs of rigging hardware have two categories of items: "for overhead lifting" and "not for overhead lifting".

In most cases, it has to do with quality control/traceability from raw material processing to out-the-door delivery.

The imprimatur "For Overhead Lifting" is a CYA, which doesn't mean that a particular fastener w/o that conference is not appropriate for the job.

I attended an entertainment rigging/hoist maintenance training conference some years ago, and one of the first things the C/M Hoist reps said was "By the way, none of our hoists are suggested for overhead lifting".

 

[Jim McKeveny]

Re: "For Overhead Lifting"

Catalogs of rigging hardware have two categories of items: "for overhead lifting" and "not for overhead lifting".

In most cases, it has to do with quality control/traceability from raw material processing to out-the-door delivery.

The imprimatur "For Overhead Lifting" is a CYA, which doesn't mean that a particular fastener w/o that conference is not appropriate for the job.

I attended a rigging/hoist training conference some years ago, and among the first things the C/M Hoist reps - jolly and quite aware that thousands of their inverted hoists were used in entertainment - said was "By the way, none of our hoists are suggested for overhead lifting".