# Your opinion on this rigging



## Dagger (May 2, 2016)

Saw this on a gig.

What's your opinion on it , 
Looks sketchy to me what you guys think


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## danTt (May 3, 2016)

It's hard to know how much weight that booth is, and this may be relatively safe, but I would say it's certainly not best practices. In a lot of places, the webbing that the chain hoists are connected to would need to be backed up with steel. Quicklinks are always a less than ideal option, and hanging a hoist from the center of a piece of schedule 40 on what looks to be at least a 10' span is certainly not ideal. Jr Clancy lists the point load at 1/3 deflection of a 10 piece of sched 40 to be 133lbs.


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## egilson1 (May 3, 2016)

Not a great plan to use pipe like that. 

Sent from my iPhone using Tapatalk


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## bobgaggle (May 3, 2016)

I don't understand the quick link at all. Why not hook the webbing directly and eliminate another point of failure from the system? I haven't done much event rigging but I've never seen webbing used to hang anything. Span sets or chain. Also in the fourth picture we see a hoist hanging on the far right end of the pipe, outside of the two points. Enough weight will lift the left end of the pipe and potentially let the hoist slide right off the end of the pipe.

Concur with the others that pipe is not the way to go. Truss or bridled points...


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## DuckJordan (May 3, 2016)

Takes the stress off the hook and puts it in the quick link. Same reason you never hoor directly to a basket or bridle


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## danTt (May 3, 2016)

DuckJordan said:


> Takes the stress off the hook and puts it in the quick link. Same reason you never hoor directly to a basket or bridle


That would make sense if this were a shackle, but I think a quicklink is only designed for linear loads as well. So you aren't really making anything safer by putting the stress on the sides of a quicklink vs the hook, and I think I'd trust the hook to hold in this case more than the quicklink... Not that I'm saying it's the right solution, just that the quicklink doesn't make it less wrong.


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## DuckJordan (May 3, 2016)

Oh absolutely this shows a little knowledge is dangerous thing


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## What Rigger? (May 5, 2016)

I would definitely not use the maillion/quick link to attach to that hook- that's a job for a properly sized shackle. I've used webbings to hang systems before, but with the understanding that they melt just as fast, maybe faster than, a non-Gacflex roundsling.


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## porkchop (May 7, 2016)

The quick link is my largest concern. I'd be willing to believe someone that told me it was rated for the weight it's holding, but have some serious doubts that it's rated for the 5:1 minimum safety factor required for overhead lifting.
The nylon webbing probably has more than adequate lifting capacity, but depending on the state this is happening likely doesn't deal with fire in an acceptable manor.
As previously stated, in a situation where all the connecting means where more ideal I would question the pipe the hoist is connected to, but looking at your pictures that seems like it would be a second order concern. 
It's one of those things where I would expect this to work, but not like it. This is why there's such a thing as safety factor and why you can't get manufactures to tell you information like MBS.


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## Dagger (May 17, 2016)

If not possible to make
Bridle or truss

Would hanging the chain fall of a double steel pipe ( two steel pipes attached parallel with chesseboros) 
work?


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## Footer (May 18, 2016)

Dagger said:


> If not possible to make
> Bridle or truss
> 
> Would hanging the chain fall of a double steel pipe ( two steel pipes attached parallel with chesseboros)
> work?


No. Truss/beams gets their strength from how far apart the top and bottom cords are and how often they are connected together. Connecting two pipes with cheeseborough does not put the pipes far enough apart and not often enough to do anything useful.

Once again, this thread scares me.


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## Dagger (May 18, 2016)

I showed

Footer said:


> No. Truss/beams gets their strength from how far apart the top and bottom cords are and how often they are connected together. Connecting two pipes with cheeseborough does not put the pipes far enough apart and not often enough to do anything useful.
> 
> Once again, this thread scares me.



I showed the pics to one of the guys on a gig he suggested using 2 steel pipes w cheeseboros

Also he says looking at the high steel 
You can't Bridle from there ...


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## rochem (May 18, 2016)

Dagger said:


> Also he says looking at the high steel
> You can't Bridle from there ...



Why not? The hoist would land slightly below the level of the low steel, but assuming that you're not extremely limited by trim height, that's an easy bridle to make. And if you do need it tight to the low steel, you may be able to DO ALL THE NECESSARY CALCULATIONS AND POSSIBLY make a slightly looser bridle that will keep the hoist above the low steel - emphasis on the calculations, as bridles start to get scary when you increase the angle even slightly beyond 90°.


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## Dagger (May 18, 2016)

rochem said:


> Why not? The hoist would land slightly below the level of the low steel, but assuming that you're not extremely limited by trim height, that's an easy bridle to make. And if you do need it tight to the low steel, you may be able to DO ALL THE NECESSARY CALCULATIONS AND POSSIBLY make a slightly looser bridle that will keep the hoist above the low steel - emphasis on the calculations, as bridles start to get scary when you increase the angle even slightly beyond 90°.




90 degree u are referring to where the two bridle Legs come down to make the point?

This was a huge gig 120 points

Looking at it i am not sure
But don't some of the bridles look like they are pass 90 degrees??

(Specifically the one in the front on the top right corner a little above the catwalk )


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## Footer (May 18, 2016)

Dagger said:


> I showed
> 
> 
> I showed the pics to one of the guys on a gig he suggested using 2 steel pipes w cheeseboros
> ...



He's correct. You should not build bridles off roof trusses like those, they can't take horizontal loading.


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## Dagger (May 18, 2016)

Footer said:


> He's correct. You should not build bridles off roof trusses like those, they can't take horizontal loading.



Then how to rig his particular thing at this venue ??

Can't use pipe ,can't use bridles , can't put a truss ....
What's the solution???


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## Footer (May 19, 2016)

Dagger said:


> Then how to rig his particular thing at this venue ??
> 
> Can't use pipe ,can't use bridles , can't put a truss ....
> What's the solution???



Ground Support. Or stick truss instead of that pipe. Granted, that pipe could be used if the math was able to back it up. You can do anything you want as long as your numbers are good. 

If that pipe is 1-1/2 sch 40 and you have a 10' span you can do 200# center point load. Way over that here. Best case scenario they are using 2" sch 80 structural pipe and can do roughly 450# CPL with a 10' span. If the span was 6' they could smash 1200# on that pipe... but I don't think that is the case here. Either way, that leaves little wiggle room. 

Ground support is sometimes the way to go.... especially in rooms like this that were never built for additional roof load. Those light duty roof trusses are meant to hold tar and AC units... not dynamic loads.


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## Dagger (May 19, 2016)

Footer said:


> Ground Support. Or stick truss instead of that pipe. Granted, that pipe could be used if the math was able to back it up. You can do anything you want as long as your numbers are good.
> 
> If that pipe is 1-1/2 sch 40 and you have a 10' span you can do 200# center point load. Way over that here. Best case scenario they are using 2" sch 80 structural pipe and can do roughly 450# CPL with a 10' span. If the span was 6' they could smash 1200# on that pipe... but I don't think that is the case here. Either way, that leaves little wiggle room.
> 
> Ground support is sometimes the way to go.... especially in rooms like this that were never built for additional roof load. Those light duty roof trusses are meant to hold tar and AC units... not dynamic loads.




It's hard to tell from Those pics but no span sets were used . Those are all slings on high steel . Ur thoughts ?


1)I am trying to look for the chart Christie LITES provides , it basically states how much weight vs how long truss weight can take 

Ex. 32 feet of truss has CPL of 250lbs. ( I could be wrong with the 
Numbers , I have seen the chart I just can't find it anymore )


2)Also 
What is 1-1/2 sch 40 or sch 80

Is there a chart I can refer to?

3)The shorter the spanset the more weight it can take? Does it matter how many wraps around the pipe or steel you making ?

Thx


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## josh88 (May 19, 2016)

When Footer says span he doesn't mean spanset the distance its spanning. IE 
|-----10'-----| vs
|---6'---|

the shorter distance between the two points means there will be less deflection and it can support more weight before it all comes crashing down.


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## Footer (May 20, 2016)

Dagger said:


> It's hard to tell from Those pics but no span sets were used . Those are all slings on high steel . Ur thoughts ?
> 
> 
> 1)I am trying to look for the chart Christie LITES provides , it basically states how much weight vs how long truss weight can take
> ...



All truss is different. There is no hard and fast capacity for a given stick at a given size. You have to look up what the capacity is per manufacture spec. 

You need to start reading more. 
http://www.amazon.com/dp/024080354X/?tag=controlbooth-20
http://www.amazon.com/dp/0692309896/?tag=controlbooth-20
http://www.amazon.com/dp/0809327414/?tag=controlbooth-20

And Donovan's book that you already bought. Until then, I'm afraid we can't really be too much more help. What you don't know is what makes you dangerous. I would be afraid to give you too much info that you can't backup with numbers down the line. There is no hard "rules" to rigging. Every job is different. Every space is different. There are standards that you can lean on but you need to be able to trust that whatever you attaching to will actually be able to take the load.


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