How long is Temporary?

[Tyler Herron]

I posted a thread awhile back about all of my rigging being installed using chain baskets. Someone mentioned thats pretty common but it's better to use beam clamps on installs. I've heard chain baskets are good for temporary things, as well as things like wire rope slings with burlap.

Last year I also had my building inspected by a structural engineer in anticipation of bringing in a rigger to do some special event stuff. The report came back as follows: Each beam can hold an additional 750 lbs of weight within 60ft of the proscenium. Outside of 60 ft, the beams can only hold an additional 500lbs and it can only be temporary.

My question is, how long is temporary? A week, a month, overnight?

I VERY rarely have the need to hang anything out that far, the reason I ask is because we change sets out about 3-4 times per year. Some sets stay up longer, others don't. You know how it goes. If I'm wanting to hang some sticks of truss from our beams, can I get by with burlap and wire rope baskets? Or chain baskets? For 3 months? What are you're thoughts?

Or should I just suck it up and grab a bunch of beam clamps? Also, while on that subject another quick question. The rigging company that helps us out a bunch obviously has plenty of equipment. They typically use 3 Ton beam clamps when they hang stuff. Obviously pretty overkill as each beam can only less than a 1/2 Ton. What do you guys think of the 1 ton beam clamps from rosebrand? I bought a couple to use for a one off event but was unimpressed. They are stamped with manufacturer (Peak Trading?) and made in..china. They also came with certificates of inspection. That all makes me feel better, but I'm having a tough time getting over the china made nature of it. And it just doesn't "look" like I should be using it to hang stuff. I don't know. Something just doesn't sit right with me. Have any of you used them?

What are your thoughts on the temporary question?

 

[Footer]

Your fear of Chinese stuff needs to die. They can make things just as well over there as we can here... if not better. If it is load tested it is load tested. This "all Chinese stuff is crap" thing needs to come to an end.

The temporary thing is a real issue.... and one you won't get a straight answer for. I would go back to that engineering firm and ask. It could be they are using the snow load on your building to cover the rigging. Many summer sheds do this. Temporary is as long as you want it to be and as long as it can be.

 

[gafftaper]

Throw out the Chinese beam clamps and get some new ones. I do most of my rigging shopping at Sapsis Rigging or Fehr Bros. I have some of these adjustable beam clamps from Fehr Bros and they are excellent. If you want a little cheaper single size bolt on beam clamp, Sapsis sells them.

 

[Tyler Herron]

Hmm. That reassures me quite a bit actually. I guess it's just one of those things that's been passed down to me. The skepticism of Chinese made products. Consider it dead in me at least.

Thanks for the reply!

 

[Tyler Herron]

Thanks for the sites gafftaper! I'll check those out!

 

[de27192]

Speaking as a rigger!

- I don't like chain baskets at all. Chain links are strong end-to-end, but not strong across the link. So if a link ends up side on to the square edge of a beam, you could very easily damage the chain and cause it to fail. Chain baskets need a great deal of care to install properly hence I never use them, I only advocate the use of Steel Wire Rope - with burlap - for use as baskets.

- For temporary rigging, a SWR Basket is easier & safer than a beam clamp, really. You can haul the whole chain and basket as one go and tie it on. However I would not recommend leaving a steel basket on an I Beam for more than a week or two. Beyond this time, you do risk it starting to seriously deform. I have seen a SWR basket left over a beam for 3 months and there was serious deformation in the steel and some of the outer cores on the sling had started to break. So you can see - if you're leaving stuff in place for 3-4 months, a SWR basket is not the one for you.

- Strictly speaking, a scissor type beam clamp is not designed for permanent installation, but for temporary. As has already been alluded to, the point at which permanent becomes temporary is a vague line and nobody ever knows the answer. But 3-4 months, in my book, is at least semi-permanent. Talking common sense, you would be safe with a beam clamp for this job.

If you're frequently rigging in house, getting a structural engineer in to do the survey was the right thing to do, now the next right thing to do will be to get a rigger working on your books rather than trying to do it yourself. He'll be able to tell you these things in person, and help you to choose the right equipment to do the job.

I agree about not throwing out the chinese beam clamps straight away. China is capable of producing the same high quality goods as found in the west. However China is also capable of producing utter crap that is no good to anybody. The key is to make sure yours are from the former category. So - do they have American standards markings? IE an ANSI number? Have they been quantified as good by an American body or have they come straight from China? In the former instance - use them, they'll be fine. In the latter, be much more cautious. Chinese goods are harder to prove as being up to the grade, so if they've not been marked and supplied by an American company, I would be inclined not to take the risk, and to buy some more from an American dealer who will supply either US-made or at least US-stamped goods.

But again, see what your rigger thinks. There are people below suspended loads so it is not a question to ask the internet.

 

[porkchop]

Temporary is a sticky situation that's had to answer. I know a group that was clearly permanently installed, but did silly sounding things like unplug everything (load-out) and plug it back in (load-in) once a month so they could claim it's temporary. It never became an issue, but I have my doubts if that would have stood up against an inspector. I could argue for 3 or 4 months being temporary, but wouldn't be surprised if an inspector or an insurance company didn't like that definition.

As far as you beam clamps go I would prefer to have larger capacity beam clamps to give additional safety factor and to allow points that aren't straight vertical if need be, but 1-ton sounds like it would do the job. China makes some great stuff like your cell phone and probably the majority of the components inside your computer. They also have some good steel companies that sell certified products that are just as good as anything else on the market. They also have companies that will produce knock off products for as cheap as possible. What you as rigger need to do in selecting your rigging hardware (and by need I mean are required by law) is look into how it's been tested against it's listed rating. ANSI has testing standards that are commonly considered standard in the US and things that have been tested to European standards will have a CE approval. Rosebrand has a good reputation, but their website doesn't say anything about their 1-ton beam clamps being certified or approved by a standards writing body. Hopefully it's stamped on the product and it's just not listed on the website. If not I would contact them and see how they ensure that the clamps can actually hold the rated capacity.
If we where talking about a non-standard product (not a beam clamp) and, for example, they destructively tested 100 of them to find the MBS, derated appropriately from that, and continue to test 5 out of every batch to ensure continued quality. In that case, I'd probably be willing to use them. If on the other hand the only response was "That's what the manufacturer says they can hold" and they have no information on how the manufacturer came to that rating then I'd look elsewhere. Beam clamps though are a pretty common product that are made by a lot of vendors so I'd just look for something with an ANSI approval since I'm located in the US.

 

[techieman33]

Your fear of Chinese stuff needs to die. They can make things just as well over there as we can here... if not better. If it is load tested it is load tested. This "all Chinese stuff is crap" thing needs to come to an end.

The temporary thing is a real issue.... and one you won't get a straight answer for. I would go back to that engineering firm and ask. It could be they are using the snow load on your building to cover the rigging. Many summer sheds do this. Temporary is as long as you want it to be and as long as it can be.

They can absolutely make good quality stuff. They also make a lot of cheap knock offs that look just like the good stuff, but would fail to pass the same standards. It can be a challenge sometimes to tell the two apart. It's just easier to buy domestic steel and take all of the guess work out of the equation.

 

[BillConnerFASTC]

The temporary is a good question, and the duration varies widely. From the National Design Standards for wood structure, some values (for design formulas): So hard to say. IBC uses 180 for temporary structures (like a shed to sell Christmas trees or a construction office or whatever). LSC uses 30 days for platforms - like a head table in a ballroom or a boxing ring in an arena. I believe the NEC uses 90 days for wiring. You need to ask the engineer.

 

[robartsd]

If I were reporting on the capacity of a structural member to resist additional load, I'd use a "live load" duration as the basis of my analysis unless I had specific reason to use a different duration. I might use the word "temporary" as a laymen's term for the live load not being permanent.

There are various reasons for allowable "temporary" loads being different than permanent. One reason would be the properties of the structural material. Wood can be very resiliant over short durations, but develop permanent deformation from long-term loads (thus the NDS values for various load durations). The IBC and NEC definitions of "temporary" are more about risk management. Structures and wiring that are removed after a short duration have less time to develop/experience problems and there is a greater chance that deterioration will be noticed and corrected when it is taken down or set up again.

 

[Tyler Herron]

For what it's worth to everyone, I bought some extra beam clamps from Sapsis rigging. The first batch I bought from Rosebrand and they were the "China" made ones I was skeptical about in the beginning. I went with Sapsis after hearing some responses from you guys. It turns out, the 1 Ton beam clamps from Sapsis are the exact same ones Rosebrand sells. Sapsis is just $.50 more expensive at $43.50 so it doesn't really make a difference either way. Just figured I'd throw that out there.

 

[egilson1]

In 2009 when we started the task group for ANSI E1.39 the first topic we debated was the name of the document. The original title was "Selection and Use of Personal Fall Arrest Systems on temporary Structures Used in the Entertainment Industry". One of the task group members worked in Hollywood with the film studios and brought up the point that by using the word temporary we were inherently looking ourselves into defining how long that time period was, and as previously mentioned there are a vast number of "codes" that you can choose from to try and determine how long that is. If they built a set for a shoot and called it temporary, the local building inspector for instance might say it had to come down in 90 days. But what if the need for that set extended because the TV show it was for renewed for another season? We wanted to avoid using the word temporary so we could try and not be confined to a time period. That's when I had what I often joke about being the only retaliative input into the standard.

I recalled that article 520 of the National Electrical Code which is what theatres, studios and most live event venues fall under often used the term Portable to describe equipment. If we used portable in the fall arrest standard then it solved the time period issue, as well as tied the definition of portable to a already accepted and used code. And when you look at what we do in the live entertainment industry most of it is indeed portable. Of course there are exception to this idea such as a show on Broadway that has been running for multiple years,. but for the mot part the equipment is designed to be moved from location to location. Based on that I like to refer to non permanently installed equipment as portable and not temporary. You can argue that it's semantics but in code/standards/OSHA a lot of things come down to semantics.

Regards,
Ethan

 

[MikeJ]

Throw out the Chinese beam clamps and get some new ones. I do most of my rigging shopping at Sapsis Rigging or Fehr Bros. I have some of these adjustable beam clamps from Fehr Bros and they are excellent. If you want a little cheaper single size bolt on beam clamp, Sapsis sells them.

Those are nice clamps, I have used them a lot, and actually The Dayton models sold at grainger and anywhere else, are 2X the price, so thank for the link. The 3 tons are useful for wider beams even if you don't need the extra rating.

 

[egilson1]

The discussion of Imported vs. Domestic hardware is no longer as black and white as it use to be. As has been pointed out more and more distributors are selling products made overseas and verifying their quality and strength before they are shipped to the end user. A great example of this is ETC and the wire rope used on the Prodigy hoists. When they receive the imported wire rope they take a sample from each spool and break it to verify its ultimate strength. In addition they load test the entire hoist assembly before it ships. Understandably not every company has the resources to proof test imported materials, but there are some do. The point is you can buy imported hardware if you do some research on who is importing it and who is going to be responsible should something fail.

Regards,
Ethan

 

[de27192]

The discussion of Imported vs. Domestic hardware is no longer as black and white as it use to be. As has been pointed out more and more distributors are selling products made overseas and verifying their quality and strength before they are shipped to the end user. A great example of this is ETC and the wire rope used on the Prodigy hoists. When they receive the imported wire rope they take a sample from each spool and break it to verify its ultimate strength. In addition they load test the entire hoist assembly before it ships. Understandably not every company has the resources to proof test imported materials, but there are some do. The point is you can buy imported hardware if you do some research on who is importing it and who is going to be responsible should something fail.

Working abroad in the Middle East and Asia I also have experience on this. It's not the same as such, but ultimately it is not practical (or, realistically, affordable) for us to out-source all of our material requirements to the West, and inevitably have to buy local on a number of things. The price of 48mm tube in the UAE (they seem to produce a lot there) is about 10% of it's price in the UK and on the whole as long as you drive down to their yard, verify that the stuff you're buying is the spec that you asked for, it seems to be just as good as anything you can buy in the West. You have to do the check - else they will send you something so thin you can bend it in your hands. But on the whole, it's fine.

Likewise, wire rope, I have a hydraulic pull tester and a basic manual load cell which I use to proof load SWR. If we're making a batch of steel drifts I will produce 10% extra (so if we're making 20 I'll make 22) and after finishing, pick 2 at complete random, and load them til they break. This should represent the drum it's come off.

Ultimately you CAN get good kit out here, but you can't assume it to be good as you would with kit made to a standard in the West. But if you are prepared to properly monitor your suppliers and proof test the kit before committing it to a job, you can do it safely.