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Jack chain.


SceneMaster

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Posted

Hi

 

Is jack chain suitable as a safety bond for par56s. I know it has now clips but this is fine for my application I just wondered if it was strong enough for a safty bond?

 

What is it used for?

 

Thanks

Posted

Hi Scenemaster,

 

If you mean DIY jack chain from B&Q or similar I would say it's not suitable at all. The links aren't welded, and whilst it'd probably withstand a PAR56 coming adrift, it's just not the right kit for the job.

 

Proper black safety chains are only three quid each, and rated wire bonds are not much more. That way you're sure to be safe, and no-one can come up and condemn your rig 10 minutes before the show (assuming everything else is up to snuff).

 

Save your jack chain for the WC.

 

Pete.

Posted
This is the jack chain.

 

Hi I'm confused I know that I have to use safety chains (no lecture) but I need a long safety chain and wondered if this is the stuff for hanging shanderlers so would od fine for my p56s. It isn't welded so is probley not what I am after.

See this thread, which has been bubbling away for the last few days on the Blue Room and which, if you're a semi-regular reader, you can't fail to have noticed - and ask yourself whether a lightweight jack chain such as the one you describe, which has unwelded links and is intended for the static suspension of lightweight fluorescent fittings, would be suitable for sustaining the shock load that would be imposed as a result of bringing a falling lantern to a halt. Then answer your own question "Is jack chain suitable as a safety bond for par56s" ...

Posted

Thanks. I have read the safety bond thread even before I posted this topic and it answers my question about loading and the jack chain is not acceptable but not where I am going to get a 2m safety chain from. Any ideas? :D

 

Thanks

Posted

I'm a little confused as to why you need such a long safety. normally the secondary suspension just covers detachment from the hanging point - so if the hanging point also needs a safety (I'm assuming some sort of untested dropper) then this also needs a separate safety with an uprated load rating to cover the extra weight.

 

can you give some more info - maybe someone will then have a better sugestion

Posted

Hi

 

I'm droping a bar using a dropper clamp long which has been dicussed here before I need a safety bond which is rated to take the bar and its contents should it's primary attachment fail. The chain needs to be about 2m and go round both bars. I had a thought would the WELDED chain in B&Q type places be fit for this job as it is the same thickness of metal and is welded loops. The only problem is that you can never be sure whether these chains are right as they don't exactly come with load ratings. Any ideas?

Posted

hi there,

 

If this bar is not used for flying (i.e. more than one lifting operation), then you could buy some rated 6X19 steel wire rope and make a sling using the correct number of din1142 dogs. This would be acceptable as a secondary safety.

Posted

For secondry suspension, you really need a rated drift. 'Safety Chains' are not rated by the manufacturers, whereas safety bonds are. For a 2m length, you could try buying some 2m drift wires. These combined with an appropriatly rated shackle should be able to provide secondry suspension for your bar. Its worth considering how you're going to attach to the bar - obviously a loop isnt going to be very secure, and choking the bar not much better. My advice would be to go for one of these:

http://cgi.www.doughty-engineering.co.uk/theatre/products/photo/T32000.jpg

T32001 - Hanging Clamp With Ring (48mm) from here.

 

Hope this helps.

 

 

Peter

Posted
Or just use more drop clamps. The secondary doesn't have to be a chain or wire. As long a you use enough clamps so as if one fails or comes off the bar will still not fall you should be fine.

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