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[Nathan Riddle]

Nathan, DO NOT use anything not rated for overhead lifting in an overhead lifting scenario.  If the manufacturer won't stand behind their product, you don't want to stand under it.

I agree. But why are current practices not heeding the manual?

(first two images)
http://www.cm-et.com/Public/28916/Classic%20Lodestar%20Maintenance%20Manual.pdf

(third image)
http://www.cm-et.com/Public/31110/ProStar%20Maintinence%20Manual.pdf.

Does that mean the ProStar can HOLD** loads over people, but it isn't certified to MOVE loads over people?

My current understanding from reading the manuals of the CM lifts are not for lifting loads over people unless multiple attachment points are used for redundant safety.

The exception to this is D8+ rated motors.

[Mark Cadwallader]

The reason for the backup or replacement of polyester spansets with steel is that in a fire situation the polyester spansets will melt through and allow rigged equipment to fall on the public and/or safety personnel. The practice started with rigged drapery and has spread to become good practice under all rigged motors.

I've never seen anyone backup a motor or hoist, as those items aren't going to easily melt and allow the rigged items to fall. Certainly the possibility of failure is there, but manufactures such as CM have done everything they can to reduce that possibility. The passive braking systems on CM motors will hold much more than the rated capacity of the motor itself.

IIRC, Global Truss towers are shown in their catalog with a steel cable sling that provides back up support to the chain hoists/chain motors used for lifting. Likewise, Sapsis makes a reference to using one of its products to hold a chain motor on a grid, which allows the load to be dead hung, thereby taking the load off the chain motor "per manufactuer specifications."  I'm not a qualified CM chain hoist tech, and I don't know if the spec is only for non-temporary hangs. That said, I know of safety-conscious municipal venues that use chain motors for part of the house rigging that doesn't use safety backups or deadhangs.

I wonder if the claimed "spec" is primarily CYA from the maker of the hoists.  As with all such matters, consult a qualified rigger for real advice and/or suitable implementation.

Edit:  Nathan, the distiction you make between "lifting", "suspending", "holding", and "moving" loads may well be a crucial one, and they may be terms of art in the rigging world.

[Nathan Riddle]

I would think you would want to rent motors, hire out the rigging too.  I know my insurance forbids us doing any rigging.

WRT the truss.  Don't buy spigoted truss.  You will hate it for the rest of your life.   Get flanged bolt together.  I just bought a pallet more of spigoted trust with the expressed plan to move it all to totem duty as soon as I can afford big boy truss.

I didn't consider insurance, thanks for reminding me!

I agree and don't agree at the same time 

Having used both, I feel like they both have their purposes. Just like everything else they are a tool.

These guys use pinned (spigoted) truss.
http://www.sxsevents.co.uk/
https://www.litectruss.com/
https://www.youtube.com/watch?v=eDMdbx0K6QQ

Nathan, I buy the limited rigging supplies I have from folks like Sapsis and Fehr Bros. - industry standard suppliers. That gives me at least the knowledge that I'm not buying questionable gear. (I also try to buy U.S. made, even at a premium price, but that's just me.) 

Regarding rigging (I am not a certified rigger), it is my general understanding that webbing spansets on truss "should" to be "backed up" by steel cable (unless you have steel-cored spansets).  A suitably-rated steel cable as a back up to a motor or chain hoist is a good idea, even if it is not presently industry practice. Industry "standards" are usually the minimum acceptable way to do things, and not necessarily the preferred method.

I assume you have a safe way of reaching your rigging points for the initial placement of a beam clamp, such as a sissors lift or similar.

Finally, have you used a manual chain hoist to lift something 20 or 30'?  I don't know if it would be a particular labor saver, especially given the need for a person on each hoist. I've used chain-hoist loading dock doors, and it isn't a very fast way to do things.

Food for thought; YMMV.

Thanks, good points. I too try to buy from a reputable rigging supplies store. That was in the past though and you make good points. I should ONLY buy from reputable places and/or manufactures. (sometimes finding deals at other places for reputable equipment is too good to pass up, also used).

Yes, I agree with the span sets, and will only use steel-cored round slings/webbing/spansets going forward (If I continue to pursue this avenue).

Yes. I would use the correct lift, scissor or other.

Perhaps, I still see having manual chain hoists as beneficial at times for known loads & structures. Sure motors would even better, but they require renting (or purchasing) and are expensive and would be further hassle if power requirements weren't met, etc.

The reason for the backup or replacement of polyester spansets with steel is that in a fire situation the polyester spansets will melt through and allow rigged equipment to fall on the public and/or safety personnel. The practice started with rigged drapery and has spread to become good practice under all rigged motors.

I've never seen anyone backup a motor or hoist, as those items aren't going to easily melt and allow the rigged items to fall. Certainly the possibility of failure is there, but manufactures such as CM have done everything they can to reduce that possibility. The passive braking systems on CM motors will hold much more than the rated capacity of the motor itself.

Same here, yet all the material I read it is a best practice and should be done, but not required as of now. I admit, having to safety every single hoist would be a huge hassle. I would just hate to see a chain, shackle, motor, brake, pick, I-beam, whatever fail.

I've always been have a backup for the backup type of guy, even before knowing about rigging.

[Jean-Pierre Coetzee]

I would be mildly sceptical about second hand rigging gear, generally anything that has been dropped should be discarded(more specific to shackles and clamps and other forged stuff but it still applies) and you really don't know how it has been used in the past.

[Jean-Pierre Coetzee]

Our goto structural engineer here in sa(and hang needs to be coced) demands a safety.

[Nathan Riddle]

Nathan, DO NOT use anything not rated for overhead lifting in an overhead lifting scenario.  If the manufacturer won't stand behind their product, you don't want to stand under it.  Rigging accidents happen, and the Chinese and other low-cost manufacturers are very good at making nice-looking but dangerous pot metal junk of which one batch may be perfectly fine, but the next may have weak spots that will fail.  As an example, I have several load straps where you pull the webbing through a spring loaded clamp to secure.  After a few years of use, on more than half of them the spring end has pushed through the pot metal friction clamp.  I don't know what they put in that thing, but it's sure not any normal metal.

I agree with the other posters - floor-mounted stands and truss is relatively easy to do in a safe manner, and it's a known system.  Attaching to the building structure brings much more liability, and for good reason - a lot more can go wrong.

Regarding truss - Scott is correct in that the big boys use bolted/plated truss as it's easier to assemble when things aren't perfectly aligned. That said, spigoted truss is actually stronger than plated truss and works fine in reasonable quantities.  If you go this route, I would recommend the Cosmic F34P "premium" truss, which is 3mm tube wall instead of the more usual 2mm tube wall.  This is much more rugged and will withstand more bumps and scratches before the tubes deform.

Okay, I think I'm narrowing in on what I want/need to do.
No rigging from the structure, as that's a hassle.

But, It's more expensive, but the footprint of a short tower with sleeve block & 30" base is less than that of a crank tower's legs fully extended.

Thus I can maintain ease of setting up equipment (attach & low height, raise for performance, lower for teardown), and keep the smaller footprint in the front. (which are my primary goals/desires).

Still that requires, top hats for hoists, chain hoists, and sleeve blocks.

F34 GROUND SUPPORT TOP SECTION
http://www.globaltruss.com/ProductDetails.aspx?ItemNumber=294&MainId=16&Category=36

1 TON MANUAL CHAIN HOIST
http://www.globaltruss.com/ProductDetails.aspx?ItemNumber=274&MainId=16&Category=39

SLEEVE BLOCK FOR 12" TRUSSING.
http://www.globaltruss.com/ProductDetails.aspx?ItemNumber=293&MainId=16&Category=40

At a minimum I'm looking at this, AND/OR purchase the crank stands that I finalize in my crank stand thread.

What would be a comparable company that is considered premium for the previously stated items?

I would be mildly sceptical about second hand rigging gear, generally anything that has been dropped should be discarded(more specific to shackles and clamps and other forged stuff but it still applies) and you really don't know how it has been used in the past.

I concur, which is why if I ever buy used rigging materials it would ONLY be motors/crank stands & it would be from a company who would have it inspected and re-certified before shipping.

[Tim McCulloch]

We have truss and tower from Applied, Tomcat, Thomas, and Ultimate Structures.  We have other aluminum parts from Penn-Elcom.

I don't recommend anything by Global based on negative impressions from actual use.  Ditto for Chauvet.

[Nathan Riddle]

We have truss and tower from Applied, Tomcat, Thomas, and Ultimate Structures.  We have other aluminum parts from Penn-Elcom.

I don't recommend anything by Global based on negative impressions from actual use.  Ditto for Chauvet.

So I believe you're more in the Pro-LAB arena..?

Can you detail what your negative impressions were?

All of my truss is Global, if I'm going to either replace my entire inventory or buy a different style I need a compelling reason.

It absolutely makes sense for you big boys to have legit truss. For me it makes more sense to have cost effective trussing, in my (current) opinion.

[Scott Holtzman]

We have truss and tower from Applied, Tomcat, Thomas, and Ultimate Structures.  We have other aluminum parts from Penn-Elcom.

I don't recommend anything by Global based on negative impressions from actual use.  Ditto for Chauvet.

The Tomcat basic 12x12 plated is about a 30% premium over the Global.

I have to ask the business question.  Have you met the 5 rent criteria yet?  The labor is the largest part of providing a system "up in the air".  If you have rented 5 times and at least covered the rental and the labor then you have customers that understand the value.  If you plan on acquiring it and introducing your customers to the product I think you are going to end up doing a lot of work for free and never seeing the ROI on the investment.

[Tim McCulloch]

The Tomcat basic 12x12 plated is about a 30% premium over the Global.

I have to ask the business question.  Have you met the 5 rent criteria yet?  The labor is the largest part of providing a system "up in the air".  If you have rented 5 times and at least covered the rental and the labor then you have customers that understand the value.  If you plan on acquiring it and introducing your customers to the product I think you are going to end up doing a lot of work for free and never seeing the ROI on the investment.

I'm not sure what this has to do with our product choice but I find Global truss to be difficult to use, the lacing braces do not line up correctly end to end and their spacing means many moving lights with half-coupler clamps can only be mounted in specific places.

If you can recoup a truss purchase in 5 rentals you have better paying clients than we have.

[ProSoundWeb Community]