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Hanging Cables Safety precautions

#1 User is offline   JCC1996 

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Posted 30 April 2012 - 07:44 PM

Hi,

This question is in retrospect of an event, but I just wanted to know what the correct course of action would be in future?

We were running the tech for a school fashion show and as part of that a video link was run from the back of the hall to a projector at the front of the hall. This was done by running a long phono cable from the camera to the floor directly below a balcony (about 5 metres), then running the cable vertically up to the balcony and along the balcony to the projector. The balcony was completely out of bounds to everyone except tech personnel and we used trip protection the whole way along the balcony as well as on the 5 metre run to the floor below the balcony.

One of the teachers had set this up and left loose strand of cable from the floor up to the balcony, which we (and the head of drama) weren't happy about. We only found this a few minutes before doors open so we rushed to sort something out.

We tightened up the cable as much as possible and securely taped it on both the balcony and the floor. We then put a few tensile barriers around it, blocking off around a square foot around the cable. We also wrapped round little tabs of hazard tape around the cable to increase its visibility.

Were these precautions the right thing to do, or is there anything else that should have been done?

Joe
The probability of something going wrong varies inversely with the time until curtains up
The more the need for panic, the calmer you should look. Just walk calmly and say 'I am the technician. I know what to do.' - Wise words from a brilliant teacher!!

#2 User is offline   lite_lad 

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Posted 30 April 2012 - 08:16 PM

wrap the audience in bubblewrap?

#3 User is offline   DeepSpacePenguin 

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Posted 30 April 2012 - 08:30 PM

strobes and sirens
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#4 User is offline   paulears 

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Posted 30 April 2012 - 08:35 PM

I suspect that you did perhaps over-react, but without a picture we can't be certain. In theatre especially, we constantly need to get a cable from perhaps the stage floor up to the fly rail, then down again somewhere else.

You need to do a risk assessment - that's all.

Is the loose cable a trip hazard? It's not quite clear, but your worry seems to be the bit of the cable from the floor going up? So are we talking about a cable dangling down in the clear, with nothing around it, so people could walk into it? If this is the case, then your risk assessment would seem to say - yep it's a hazard, what can we do about it? The usual solution would be run it across the floor, with protection, then maybe up the wall.

If on the other hand you are worrying about a cable running up a hard surface like a wall, then I guess people sliding along the wall could catch it, and then perhaps tug the cable down, if not fixed properly up top! Or pulling up the cable on the floor, if gaffered down.

You made a hazard zone around the cable, suggesting to me we're talking about a cable just dangling in free space. While perhaps a worthy try - if there are people in the area, and even worse, if it will be in the dark, then your RA might reveal the likelihood of people running into it as pretty high. The barriers probably stop people walking into it, so they worked - but it's an inelegant solution - surely the real solution was to run the cable a different way - which would be less of a problem, but probably need a longer cable. Vertical drops are actually fine, if they're protected in some way - by running down a surface, or following a bit of pipework, or some other building feature. I school situations - a nice simply solution is those office type dividers - often with soft fabric on one or both sides - they usually tall enough to stop people walking into the cable, and it's just a case of a drawing pin and bit of string to keep the cable and the top in position, and then maybe a cable tie to one of the feet to stop the cable being tugged. People avoid the screen, they probably don't even see the cable attached to it!

#5 User is offline   nathan1 

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Posted 30 April 2012 - 08:43 PM

I think it's good to see a younger member of the forum taking public safety as seriously as Joe clearly does...

I'd echo what Paulears says, probably best to run the cable another way, but for a 'last minute' solution you could have done worse (for example done nothing about a situation you weren't happy with).

#6 User is offline   JCC1996 

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Posted 30 April 2012 - 09:12 PM

Hi,

Thanks for the comments, I definitely would have done it differently. In fact I'd have done away with the cable run completely and used the patch panel which was already set up and able to be used, but the run was in place before we had a chance to do anything.

Thanks

Joe
The probability of something going wrong varies inversely with the time until curtains up
The more the need for panic, the calmer you should look. Just walk calmly and say 'I am the technician. I know what to do.' - Wise words from a brilliant teacher!!

#7 User is offline   kerry davies 

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Posted 30 April 2012 - 10:46 PM

In which case Joe, well done. An RA was made and remedial action taken. None of us can second guess a better solution unless we were on-site.

I can't quite envisage the scene but just in case do remember next time that the balcony run of cable, being out of bounds to the public, caused no trip hazard. Nobody to trip up!

#8 User is offline   paulears 

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Posted 01 May 2012 - 07:28 AM

I often wonder if we should pay more attention to the out of bounds/private areas. Only last week, we had engineers in, when we weren't there and they lowered our front truss to do the safety checks - however, my system to deal with the surplus cable to allow it to be brought in, isn't exactly obvious - and as a result the other route to the roofspace, used by just me - I think, ended up with one single bit of TRS stretched across it at my neck height. While fixing it, it did occur to me that I use the shortcut during shows - in the dark and on my own. Makes you think!

#9 User is offline   OllieDuff 

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Posted 02 May 2012 - 01:10 PM

View Postpaulears, on 01 May 2012 - 07:28 AM, said:

I often wonder if we should pay more attention to the out of bounds/private areas. Only last week, we had engineers in, when we weren't there and they lowered our front truss to do the safety checks - however, my system to deal with the surplus cable to allow it to be brought in, isn't exactly obvious - and as a result the other route to the roofspace, used by just me - I think, ended up with one single bit of TRS stretched across it at my neck height. While fixing it, it did occur to me that I use the shortcut during shows - in the dark and on my own. Makes you think!


^This. Technicians are people too!

To the OP, Doing It Properly™ in a school/college environment? *gasp* Having read some of the archives in my college theatre (and removed some of the more horrible "temporary" installs) I am convinced that it was maintained by the local branch of Bodgeit & Scarper Inc. Kudos to Joe for actually thinking about it. I'm perplexed that the teacher ran a separate cable despite the fact that there was an available video patch, staff members usually have a longer memory than students in my experience.

#10 User is offline   ojc123 

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Posted 02 May 2012 - 07:41 PM

View PostOllieDuff, on 02 May 2012 - 01:10 PM, said:

To the OP, Doing It Properly™ in a school/college environment? *gasp* Having read some of the archives in my college theatre (and removed some of the more horrible "temporary" installs) I am convinced that it was maintained by the local branch of Bodgeit & Scarper Inc. Kudos to Joe for actually thinking about it. I'm perplexed that the teacher ran a separate cable despite the fact that there was an available video patch, staff members usually have a longer memory than students in my experience.


I'm in the process of removing a number of temporary installs which became permanent simply because I never had time to sort them when I was teaching full time. I put them in and they are a bit rough; safe but rough. I suspect lack of time is the main reason for school systems being poorly maintained. If school theatres have a technician then they can be fine but teachers don't have the time.

Corporate memory in a school is very short. Within two years teachers are forgotten. New staff come in. In this case it might be that a new teacher comes in and is asked (or volunteers) to video the show. He runs a cable because he doesn't know any better, no-one's told him there's an alternative system and he's doing it just after the Y10 class who've been throwing chairs at each other. He's not in the habit of doing things like this and doesn't think about the problem. In fact the only things he is thinking about is how he's going to mark the coursework for the deadline, and whether he'll get judged outstanding in his observation next week. I can think of a number of similar scenarios which would explain why this happened. After nearly thirty years in schools nothing surprises me.

The solution seemed about the best Joe could do in the circumstances. I suppose the learning is to think about how you would stop such a thing happening again if you had the authority.

This post has been edited by ojc123: 02 May 2012 - 07:42 PM

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#11 User is offline   Junior8 

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Posted 03 May 2012 - 11:20 AM

View Postojc123, on 02 May 2012 - 07:41 PM, said:

Corporate memory in a school is very short. Within two years teachers are forgotten.

The solution seemed about the best Joe could do in the circumstances. I suppose the learning is to think about how you would stop such a thing happening again if you had the authority.


These are such good points. In order to eradicate a load of mains cables for very low current equipment that had to be rigged over an emergency exit the area electrical inspector approved a quartet of dedicated 13A skts at the back of a hall that were run off an old spur for I think a 5A skt. Despite the fact that they were clearly labelled with both 'Caution - Limited Supply' and 'Drama Use Only' I sometimes wonder what they might have had plugged into them in the fifteen years since I left. (I am not making this up - when schools were built in the fifties to a budget this sort of supply capacity was specified in many counties. After all the biggest item of kit was a Clarke and Smith Record Player. In the same building, when it was built, the utterly baffling decision to do a radio audio circuit using 3A mains fittings was also taken. There were no drawings at all for any electrical work undertaken between 1958 and 1988 either!)

On the second matter the solution I developed over the years was to make friends with the officer, as above, at the local education office concerned with electrical maintenance and when faced with a new bit of, say, audio cabling that would most likely be used again see if we couldn't get it properly installed on grounds of 'safety'. Treat them right and these folk - if they still exist of course - can sometimes magic a solution out of thin air like the new 150 Amp incomer into the stage the same building on the back of improvement work elsewhere.

This post has been edited by Junior8: 03 May 2012 - 11:33 AM


#12 User is offline   dbuckley 

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Posted 04 May 2012 - 02:03 AM

View PostJunior8, on 03 May 2012 - 11:20 AM, said:

In the same building, when it was built, the utterly baffling decision to do a radio audio circuit using 3A mains fittings was also taken.


I think you mean 2A plugs and sockets. This practice was quite widespread, even here in new Zealand they did the same thing!

In one school I attended they used Wylex plugs for the loudspeaker drop points. First (and I think) last time I ever saw the things.
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#13 User is offline   Junior8 

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Posted 04 May 2012 - 08:33 AM

You're right - 2A. I must be getting old. I am getting old....

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