First show in our black box, and almost got somebody killed.

[bull]

So im in the new black box theatre hanging some lights for our first BB show which opens next thursday. I was hanging a couple ETC pars, and everything was going swimingly. I hadn't had any equipment problem with pars lately, and had just inspected all of my lights. All of the damaged lights were on my desk in the main theatre CB. Well im hanging about my 4th par when I notice it is taking oddly long to tighten. I look at the inside of the C hook to notice a crack, going almost straight through the hook, expanding with every turn. I almost freaked, was in more of shock as to how the &$(@ the megaclamp got that cracked. So I pulled it down and replaced the clamp. But still... I mean really. This was just ridiculous, because I know that light was fine like a day ago when I put it on the shelf.

 

[Les]

It probably got cracked from overtightening. And, it probably wasn't 'fine' a few days ago. I'll bet there was a small hairline (maybe even microscopic) crack there that wasn't visible to the naked eye. Heck, the crack has probably been developing for quite a while now.

You say this was a Megaclamp. It wasn't a cast iron c-clamp?

How tight do you run your clamps? About 1/2-3/4 turn past finger tight is usually sufficient.

Also, I usually safety the instrument as soon as it is hooked (finger tight) to the beam. That way, a snapping c-clamp or some other kind of slip up won't cause the light to fall. Of course, there are trade-offs, like that handful of seconds while the instrument is hanging there, finger tight, while you're hooking the safety cable up. As long as you're prepared though, the reward outweighs the risk. Besides, from what I have learned using Mega Clamps, you have to back the bolts pretty far out before the opening will clear the pipe. Somewhat annoying, but very smart design. This means that even a ridiculously loose clamp is less likely to fall than an equally loose cast iron clamp.

 

[Kelite]

And hopefully the safety cable was attached as the fixture was being hung, in the event something like this were to happen....

 

[Raktor]

And hopefully the safety cable was attached as the fixture was being hung, in the event something like this were to happen....

Wouldn't have stopped the other half of the clamp from falling and cracking someone's skull though. Though I guess half a clamp is better than half a clamp and a fixture...

 

[bull]

Oh yea, I always put my safety cable on, usually before i start finger tightening, sometimes right after finger tightening. I'm pretty good at putting the cables on one handed though. And true, there was probably a microscopic crack, and the other junior lighting tech might have just pulled this one down for all i know, he had put a couple up yesterday night. And no, it was a cheap looking altman clip, im guessing an aluminum alloy, it was way to light to be a cast iron c-clamp, although most of ours are cast iron.

 

[Les]

it was a cheap looking altman clip, im guessing an aluminum alloy, it was way to light to be a cast iron c-clamp, although most of ours are cast iron.

Actually, your clamp was manufactured by Little Stage Lighting Co who, I believe, is now defunct. It is aluminum, but it should have a SWL of about 250# stamped on it (I have one just like it in storage). That number is meaningless however on a severely over-tightened clamp.

Wouldn't have stopped the other half of the clamp from falling and cracking someone's skull though. Though I guess half a clamp is better than half a clamp and a fixture...

Yup, there's no way to stop the top part of the clamp from falling, even with a safety cable but at least you have the peace of mind in knowing that you've done everything you can to protect people. There will always be other risks and factors involved -- this is the imperfect world we live in. Your last point is spot on... Better the top half of the clamp rather than the bottom half of the clamp AND the fixture it's attached to

 

[jonliles]

Doesn't look to be an Altman clamp. Their yokes aren't typically threaded into the clamp. It appears to be a knock-off. Altman, ETC and Colotran typically do cast Iron Clamps.

Where in the ATL are you? I work with Sprayberry HS in Marietta.

 

[chris325]

Usually I wait to put on the safety cable until I've tightened the bolt with a wrench, but I am always keeping a hand on the c clamp.

 

[derekleffew]

Actually, your clamp was manufactured by Little Stage Lighting Co who, I believe, is now defunct. ...

As best I can remember, (Harry) Little Stage Lighting Co., Dallas TX, ceased sometime in the 1980s.

...Yup, there's no way to stop the top part of the clamp from falling, even with a safety cable ...

Unless one uses these:

Accessories

 

[Les]

As best I can remember, (Harry) Little Stage Lighting Co., Dallas TX, ceased sometime in the 1980s.


Unless one uses these:

Accessories

Pure genius. And NO excuses not to use the safety!

 

[bull]

Doesn't look to be an Altman clamp. Their yokes aren't typically threaded into the clamp. It appears to be a knock-off. Altman, ETC and Colotran typically do cast Iron Clamps.

Where in the ATL are you? I work with Sprayberry HS in Marietta.

Im at Heritage HS in Conyers, which is the metro area, My dad lives relatively near you I believe though.

And yea, I'm not sure why I thought I saw Altman on the side... Ive been in a rush, trying to hang curtains lights, fix set pieces, find costumes, annndd memorize three acts of lines at the same time, so my mind read Little as Altman haha. Good to know though.

 

[jonliles]

Good Luck in you new Black Box and you dual role as technician and actor!

 

[tjrobb]

I pull the safety cable through the yoke with my arm. That way if the unit falls off the pipe my arm can catch it. Takes a bit of flexibility, but I'm 1/64 Gumby so it seems to work. (Obviously I go over the top of the pipe with my other arm and other half of the safety cable, kind of like hugging the pipe).

 

[masterelectrician2112]

Unless one uses these:

Pure genius. And NO excuses not to use the safety!

This design is good for safety, but when you can't detach the safety from a fixture that's not in the air, it's somewhat inconvenient if you need to use it on a fixture that does not have the safety permanently attached.

 

[bull]

This design is good for safety, but when you can't detach the safety from a fixture that's not in the air, it's somewhat inconvenient if you need to use it on a fixture that does not have the safety permanently attached.

Yea, I guess they were built with the original premise that one would replace all of their c-clamps with these... good idea though.

 

[Les]

This design is good for safety, but when you can't detach the safety from a fixture that's not in the air, it's somewhat inconvenient if you need to use it on a fixture that does not have the safety permanently attached.

Swap the clamp. At least then you'll know that some schmuck isn't going to hang it without the safety since it was 'swiped'. Then again, I guess I'm one of the ones who thinks everyone should have a surplus of safeties so the event need not occur in the first place .

 

[chris325]

Swapping the clamp seems like it would be a big hassle compared to just having enough safeties available to have one on every hung fixture, and a bunch of extras. Permanent ones seem simply inconvienent.

 

[Les]

Swapping the clamp seems like it would be a big hassle compared to just having enough safeties available to have one on every hung fixture, and a bunch of extras. Permanent ones seem simply inconvienent.

A bigger hassle is finding that half of your instruments in storage are sans safety cable. That's why my vote is also surplus.

All in all, this is a pretty moot point. One should always make sure they are fully prepared, with all the materials necessary to hang a light prior to even removing it from the storage room.

I agree that these clamps would be a hassle if you have a half-and-half inventory, but if these clamps make up 100% of your inventory, I don't see a problem.

 

[masterelectrician2112]

I have been meaning to ask the director (who is also the TD and Theatre teacher) to get some more.

 

[bull]

We don't have the money for more, so I usually end up making them. Which isn't usually a problem, but we're out of clips, so now I can't. I had to hang a ton of pars in our black box, so guess what, I now have 6 S4 JR ERSs that are safety cable-less...