How many safeties on a PAR-bar?

[derekleffew]

Vote on the poll and discuss.

[willbb123]

S4 Par 6bars, each light gets a safety double wrapped around the 6bar pipe. Once I hang the bar, two of the cables also go through the truss (normally light 2, and 5).

As for PAR 64, none if they are inside prerig, but two if they are hung with cheeseboroughs.

[DuckJordan]

1 for each clamp. I've always thought the safety cable was based upon the weight needed for being able to support the weight. 1 C clamp 1 safety...

[Morte615]

Depends on the final weight of the bar. Each light is safetied to the bar, then the bar itself has as many needed to support the weight of the bar fully loaded. The safety cables should have a rating with them, how much shock load the wire rope and connectors can support. I usually would do no less than 3, 1 on each end and 1 in the middle.

[sk8rsdad]

Steel PARs or aluminum?

[derekleffew]

Steel PARs or aluminum?

Unobtainium.

[josh88]

I'd have to agree with at least 8. More than that depending on how heavy the fully loaded bar is and whether or not the two on the bar will support that weight.

[techieman33]

2, one near each clamp, and I've never seen anything else in the 8 years I've been doing this.

[rochem]

Well, since safety cables are really designed to catch a light if the cast-iron C-clamp fails, and since there's no C-clamps holding up the individual PARs or the parbar itself, one could argue that you really don't need any. That said, assuming there weren't any safeties already attached coming from the shop, I'd probably be inclined to just use two on the parbar itself.

[Les]

Out of OCD, I'd most likely individually safety each fixture and both ends of the bar to prevent swing, should one end fail. That said, I think you'd only NEED one at each end, as the mounting bolts for the par cans aren't likely to fail if everything is assembled correctly. If you're going to worry about the bolts being undertightened, you need a better crew.

[Woodj32177]

Each par with a staged loop of 3/16" cable to the bar, and a normal safety cable on each end fixture to the truss.

[cmckeeman]

If you're going to worry about the bolts being undertightened, you need a better crew.

The point of a saftey cable is to be a last resort, if you are truly worried that any part might fail you shouldn't send it up.

But at each failure point there should be a saftey which means that each of the pars should be cabled around the bar and around the truss/batton, this way the pipe has a saftey and each par does as well

[MNicolai]

The point of a saftey cable is to be a last resort, if you are truly worried that any part might fail you shouldn't send it up.

But at each failure point there should be a saftey which means that each of the pars should be cabled around the bar and around the truss/batton, this way the pipe has a saftey and each par does as well

You know -- the lens tube of a Source Four is only held in by a small-diameter, finger-tightened belt. Why not put a safety on that -- it's just as likely to fail if not moreso than a yoke bolt?

What about cable runs -- cables are held up on electrics by tieline. A shoelace knot in tieline is far more likely to fail than a bolt. Why not put safeties on cable runs too?

-Devil's Advocate

[cmckeeman]

You know -- the lens tube of a Source Four is only held in by a small-diameter, finger-tightened belt. Why not put a safety on that -- it's just as likely to fail if not moreso than a yoke bolt?

What about cable runs -- cables are held up on electrics by tieline. A shoelace knot in tieline is far more likely to fail than a bolt. Why not put safeties on cable runs too?

-Devil's Advocate

Most cable has a tie every few feet, several connections, and a pick, all of those are saftey points which is the redundancy i'm talking about, if you run cable on truss and through span-sett that is another saftey on the cable. which is several redundancies, and sure the lens tube is held in with a small bolt but that bolt is hardly holding any weight where as the c-clamp and or yolk bolt are holding all the weight of the light, having a redundancy around the bulk of the weight makes sense a lens tube not so much. also to strengthen my 6 argument if you have two on the par bar and the bar itself fails in a way that the saftey would catch it the par could slide out unless if it is run through the bar. where as 6 through the yolks would catch any par and the bar itself which is a double redundant saftey

[zmb]

You know -- the lens tube of a Source Four is only held in by a small-diameter, finger-tightened belt. Why not put a safety on that -- it's just as likely to fail if not moreso than a yoke bolt?

What about cable runs -- cables are held up on electrics by tieline. A shoelace knot in tieline is far more likely to fail than a bolt. Why not put safeties on cable runs too?

-Devil's Advocate

And what's catching the couple pound chunk of c-clamp falling if that fails?

[porkchop]

There is some risk to anything. I think the point here is at what point do you drawing the line of risks you're willing to accept and what risks you think you need to account for. In this case accounting for a risk means an additional safety cable. That's where details like, how often is this going to be hung/struck, how experienced the people doing the hang are, and who's going to be underneath it while its in the air come into play. It's one of those things where there is no right answer. Just answers that fit a given situation.

[Pie4Weebl]

I was going to vote for 8 as a joke, but it seems.... um yeah...

[MarshallPope]

And what's catching the couple pound chunk of c-clamp falling if that fails?

Just a thought - would there be anything wrong with gaffing one side of the safety cable to the upper portion of the c-clamp? It may be more trouble than it would be worth, but it seems to me like it could keep c-clamp bits from falling to the stage in case of failure.

[gafftapegreenia]

Well it depends. Basically I see it as one safety per clamp. If the lights are clamped to a pipe, then they probably had safeties to begin with, so yeah, probably 8 safeties total.

If they are bolted on, there are probably only two clamps, so two safeties.

Now if the bar is on a crank up stand, and the 6 lights are clamped, probably six safeties. But what if they are bolted on? Perhaps no safeties at all? And how big are the bolts?

[derekleffew]

Just a thought - would there be anything wrong with gaffing one side of the safety cable to the upper portion of the c-clamp? ...

What's the rating for gaffers tape?

IF it's a concern of yours:
L&E Hangtuff™.


I don't know many PAR-bar s that are hung with c-clamp s. See also Bad c-clamps? .

[MarshallPope]

Even though it's not rated, I feel like just having a wrap of gaff or a zip tie would be a hell of a lot better than nothing at all. Sure, there's no guarantee that it would work, but at least it's something.

Like I said, though, it's just something that randomly occurred to me.

[Morte615]

I know it's good practice, but is there any code out there (in the US) that governs safties on lights and other equipment that is hung in the air? Of course the ADHJ can decide that they want something, but is there any actual code involved?

[avkid]

I know it's good practice, but is there any code out there (in the US) that governs safties on lights and other equipment that is hung in the air? Of course the ADHJ can decide that they want something, but is there any actual code involved?

There may be an NFPA reg somewhere, but the practice is based on liability.

[sww1235]

I think that safetying is based on weight, so I would have one on each lamp, and then safeties to the weight of the bar. I probably would drill a hole in the bar and thread a cable through that, so the safety would not slide off.

[65535]

I think that safetying is based on weight, so I would have one on each lamp, and then safeties to the weight of the bar. I probably would drill a hole in the bar and thread a cable through that, so the safety would not slide off.

I would probably not drill a hole in a load bearing structure such as the bar. Especially considering the hole size required for a 1/8" cable end with thimble is about 1.25"

[derekleffew]

I would probably not drill a hole in a load bearing structure such as the bar. ...

Would the live wires inside have any influence on your decision?

[Les]

My take is that clamps are a temporary attachment device, thus require a safety cable. Add to the fact that cast c-clamps are not load rated and can pop apart under the right conditions.

Are safety cables a good idea, even on lights that are bolted to a par bar? Absolutely. But are they as required as if you were using clamps? Not in my opinion.

I almost never see safety cables around fixtures hung from flush-mounted unistrut. In some cases, it's not even possible. Bolts just aren't as likely to come undone.

[65535]

Would the live wires inside have any influence on your decision?

Depends are we stateside (120V) or overseas (220V)?



I've never actually used a par-bar, good to know some if not all are pre-wired.

[Ric]

Steel PARs or aluminum?

it's alumin i um ( make sure you add the i !!)

[Les]

it's alumin i um ( make sure you add the i !!)

"Aluminum" is the American spelling. :D

I think?

[chausman]

"Aluminum" is the American spelling. :D

I think?

Aluminum is from America, Aluminium is from the UK.

Aluminum - Wikipedia, the free encyclopedia
Aluminium - Wikipedia, the free encyclopedia.

[Ric]

Aluminum is from America only, Aluminium is from the rest of the world.

Fixed

not meaning to take this off topic too far, but it is strange that it's the only element that the US has dropped the i out of for 'ium'.

[tdeater]

I look for single points of failure that someone could mess up. For me, I am safetying around the single bolt that attaches the clamp, and the clamp itself. Now, if each par is held to the bar with a single bolt that can come out easy, it might need some more safety's.

[Pie4Weebl]

Interesting enough, today we rented a bunch of par bars from the borg, and they all came with six safeties.

[ack]

My take is that clamps are a temporary attachment device, thus require a safety cable. Add to the fact that cast c-clamps are not load rated and can pop apart under the right conditions.

Are safety cables a good idea, even on lights that are bolted to a par bar? Absolutely. But are they as required as if you were using clamps? Not in my opinion.

I almost never see safety cables around fixtures hung from flush-mounted unistrut. In some cases, it's not even possible. Bolts just aren't as likely to come undone.

I agree with Les and this thinking. Except for the part in the signature about the fire ants.

[chadillac802]

I have always used only two safeties for PAR Bars, I safety all individual lights hung with clamps, but since the PARs are bolted to the bar, I see no individual need for the safety. Safeties are to back up the temporary rigging of the lights, the bolts on the PAR bar are permanent. I agree that Murphy's law is always in effect, but I personally think it's overkill to individually safety all the lights on the bar.

[Cooperhodges]

Depending on what the cables are rated for, I would go with one on each clamp. The pars are bolted to the PAR bar, so the only possible way anything could fall (given that the pars were tightened correctly) would be for one of the clamps to fail.

[Chris15]

I want to tell a story...

I was working a gig on an outdoor stage a year or two ago. I heard a ding in the orchestra while we were in bump in - the band weren't in until the next day. So I went looking and found on the floor both a nut and a washer. That's strange I thought. Looked up to see an instrument hanging from the grid on its safety cable. I guess that's where the nut came from...

Threaded fasteners can and do work loose with vibration. Anything hanging outdoors vibrates. Anything flown with movers on a truss vibrates. Airconditioning makes things vibrate very slightly.

So whatever the number of safety cables it takes, use enough that a bolt working loose doesn't leave a fixture to hang from it's mains cable if something goes wrong...