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View Full Version : DJ Booth gantry - Safe loading levels Kg?



dicky
10-05-2015, 05:19 PM
Hi folks

I was prompted to post this one after a discussion with a friend running a mobile disco

Regards the lighting gantries that I suspect many of us use on our DJ booth - how do you judge the safe lighting load you can fit?

My booth is a 6ft Vonyx, the gantry is rated by the manufacturer (and stated by the UK retailer) to be 40Kg on the gantry (evenly spread) and 50Kg on the base

Now I have around 40kG on the base (give or take a kG or so) and I also had a similar load on the gantry. Over a course of the first couple months DJing I became increasingly uncertain about the safety of the overhead gantry. On of my main concerns was that if someone (drunk?) crashed into the booth then something very bad could happen.

I also wondered very much so whether the manufacturer/UK retailers ratings are absolute maximum and if they are max ratings, whether they would be held responsible should the gantry fail, assuming I had a load withn those ratings (albeit close to the maximum)

Another thing I noticed, some of the lights I have say that you must attach a safety chain and that you must never load a gantry above 10% of it's max rating. However 4kG does not seem a lot of load!!! So which is the correct safe load and who would be responsible should it fail?

Also if some drunk brought the whole lot crashing down and injured someone (hopefully breaking the fall of my expensive lights on their soft irresponsible drunken body :p) whose liability is that?

I actually became so concerned about this (after all disco lights are expensive things and drunks are 10 a penny :devil:) that I went to some length (a couple months back) to strengthen my rig and increase the ground footprint.

Chatting with my mate he is more of the opinion it is down to the manufacturer to specify the safe load and their responsibility if it fails because he weighed all his gear and it is within the rating - just - but he is keeping an eye on his rig and evaluating the safety he says.

I wonder if it is like electronic componenets - they have an absolute maximum rating too but it is common (good??) practice not to load them above about 60-80% of it!


Oh on the upgrade I did on my booth - most of you are sure to know by now I am not afraid to make upgrades and work on kit myself, call me old school but I tend to rely on and have trust in my own abilities and judgment rather than consider things to risky to atttempt just for the outside possibility I may become liable for it..... but I don't think I am a 'heath-robinson' sort of person for all that.

The following pics show the A-frames I made to provide additional support to my lighting gantry. Note the original gantry support arms are still in place, I just suplimented them. I also fitted a diagonal strut across the base of the booth (fairly clearly visible in the first pic on the rear of the booth base ) as I was not at all happy with the horizontal play in the booth. Also the A-frames increase the footprint of the booth by an extra 0.50m depth and this seems to have greatly improved the stability and 'impact resistance' of the rig.

Frames are made from 25mm square section steel (1.6mm wall) and are bolted to the booth stand with two bolts each - along the level where the plinth boards fit, where you see the green insulation tape. Cost me about £20 in steel from a local metal stockists and £30 to get the welding done at a local metal fabricators. It's very quick to add the additional support/strut about an extra 5 mins install time) and they only weigh a few kilos so are light and easy to transport.

Once the screens are in place you don't really see the additional metalwork going on behind the scenes.

Views/criticisms etc on the H&S implications of this sort of home done upgrade would be respectfully heard :o

Personally I think I have done the right thing and am happy with the solidity of the booth now, I've suggested my friend considers similar. Over to you.

DJ Jules
11-05-2015, 07:43 AM
Regarding max vs safe working loads - it's going to be down to the manufacturer. Some you will find have expressed absolute maximum loadings, others will be quoting a "Safe Working Load" (SWL) that is actually a couple of factors under the actual max load and/or breaking point of the kit.

I suspect that there's going to be something in the CE marking guidelines about how these numbers should be expressed and I hope someone here will know about TUV certification and how load ratings have to be expressed with TUV marked equipment.

Note that you've basically created an Ultimax Sumo stand (https://www.djkit.com/ultimax/ultimax-the-sumo-stand-12m-with-sureloc-uprights-wheels-trusslite-rig.html), so clearly you're on the right track :D

Julian

dicky
11-05-2015, 09:47 AM
So I have Julian without even realising it lol

If I understand what you are saying - the responsibility lies with the manufacturer of a DJ booth and gantry if your kit weighs less than the stated load, the gantry fails, and you end up in a compensation claim? What if the manufacturer is not in the UK?

Yes I do have PLI via AmpDJ before anyone mentions it

Rich

DJ Jules
11-05-2015, 10:29 AM
The manufacturer will generally never be in the UK (unless it's Ultimax). You'll have liability if something breaks and hurts someone, but you will then have recourse against the dealer who sold it to you, and they will then have recourse against the manufacturer... This is assuming that you can prove that you weren't negligent in your maintenance and use of the item.

That all said, bear in mind that (as far as I'm aware) there has never been a claim.

Julian