Understanding Lighting Safety Cables
Vložit
- čas přidán 24. 08. 2017
- Do you know the breaking strength and working loads of your safety cables? Are you using the correct attachment method? Flyhouse did some tests to dig into the math behind it all. Learn more at www.flyhouse.com
These videos are so delightful and useful, thank you so much!
We are glad you like them. They have been fun to make!
Love your videos! Chock full of good info and very well thought out! Thank you so much!
Glad you like them!
Great video, thank you
0:55 Safety cables should always be attached to the fixture itself (if possible), rather than the bracket. On the Source4 for example, the safety cable should be attached to the small hole near the back of the fixture (not referring to the back handles). If in doubt, always check the manual.
Also it would've been cool to see a shock load demonstration. Anyways, great channel guys!
Does the breaking point rating change if using a double-wrap?
A double-wrap is a safety around the yoke of a conventional light, wrapped around the pipe, and then clipped to itself (the double-aircraft cable near the pipe). This shortens the dropping-distance substantially. Is it safer than the 2 examples you explained in this video?
An excellent and informative video.
I too have a few thoughts on making it better. A Source4 with a typical barrel (most common fixture) weighs 14lbs, your 10lb comment is misleading. I'd also love it if you would have run the math to show how heavy a light each method can catch. A few clear recommendations can go a long way with those that don't spend all day rigging.
You are not the first person to mention the math. As we move forward with videos, we will do what we can to make this better. Notes like this help. Thanks!
Would you suggest attaching smaller lights, like an ARRI L5-C, to a safety cable when storing them in the lamp dock to prevent them from falling? Would there be too much risk of them hitting the lights on the shelf below if they were to fall?
We recommend using a safety cable on any item with a single point of primary attachment. It may be advisable to make or buy short safety cables if you have a concern about them contacting other items in the case of a fall.
Where can I find more information on shock loads and how to calculate them?
Because shock loading is a concern in lots of industries, there are lots of materials out there. We don't have a video about it yet, but a quick search for "calculating shock loads" gives results from textbook physics, arborists and other perspectives. It is also covered in entertainment rigging like Entertainment Rigging by Harry Donovan and The Stage Rigging Handbook by Jay O. Glerum.
At about 1:30 your have an illustration is of a moving light, with the safety chain choked. The illustration makes it look like the chain is anchored to the yoke Since this is part of the movement system on that sort of light, that's...rather improbable... Granted, it doesn't too much change what you're talking about, but it's pretty clearly NOT the way to attach a safety chain to a light...
We did notice that after the fact. We will make sure to make a note under the video. Thanks for pointing it out!
I'd like to point out that your statement that chocking automatically makes your safety-cable longer can be fixed by wrapping around the pipe a few times before chocking, it does nothing to the "loadability" but greatly shortens the fall-distance
And I should have watched the whole movie before commenting ;-) I just heard you about the basked-to-attachment-point method. Same difference 🙂
Thanks for the comment! There a couple ways to keep the fall distance short, and that, along with using any manufacturer-provided attachment points on the body of the light, are the primary concerns when using a safety.
I am having trouble finding where safety cables are required by a law. I see many area theatres that have NO safety cables on their fixtures. I was at a theatre last night, and they used zip ties to hold the light to the girder. As a Lighting Designer, I was LIVID!. Any information that you can provide on safety cables being required by law, would be most helpful. Many do not use their brains when installing fixtures. They have no clue how many lawsuits they will face should a light fall and land on someone's head.
Most of the laws that apply in your venue are going to be local laws which will not call out secondary cables. Where the law can be applied is through the general duty clause of OSHA law. Workers must be protected from recognized hazards. ANSI standards, such as ANSI E1.4-2-2021 Statically Suspended Rigging Systems, call out that any single point of attachment should be backed up with an appropriate safety. In that case, not following the standard amounts to not protecting against a recognized hazard and thus a violation of the federal worker safety law. Rigging and other entertainment standards are available for free at tsp.esta.org.
From the standard listed above: "3.8 All single point suspensions (from attachment through load carrying device) shall incorporate a redundant point or safety line assembly as an additional safety feature unless otherwise determined in a risk assessment by a qualified person considering the single point failure hazard. The safety line shall be as short as possible to minimize the shock load on the components and anchor point. Anchor points or supporting structure shall be designed to withstand the anticipated shock load imposed by the safety line assembly."
Color pleeeease. This black and white hurts my eyes