Installing theatrical lighting

[Psyclist]

I was in a meeting with our hotel owner yesterday and he's told me that he's organising delivery of a couple of spot lights that he wants to be installed for an upcoming concert in our ballroom.

Now we've already got a scaffolding tower which will be fine and there are 13A sockets on the plastered beams across the ceiling so connection will be fine (provided they come with a 3 pin plug!).

What I'm struggling to work out is how to actually fit them to the ceiling.

Obviously I don't have the lights yet so I can't tell you what they'll be like, but my concern is the weight of them and how I will fix them to the ceiling.

I did try to suggest (after somebody else suggested buying some instead of just hiring some) that he buy them from a company who will install them, but as per usual with things I've never done before, he insisted he wants me to do it.

Does anyone have any experience with stage or theatre lighting installation who could offer any advice?

 

[ricicle]

Most theatre/stage lighting is suspended on rigging (steel tubing which is fixed to the ceiling) The lights are clamped on and are also fitted with safety chains.

You may find that if these are proper theatre lights that they have no provision for fixing them direct to the ceiling.

Will this be a permanent fixture ?

 

[bernardgreen]

Can of Worms

Locations for public performances have to meet certain safety by-laws as well as other minimum safety requirements for stage lighting units fitted above the audience area.

If they are being bought from a reputable supplier of stage lighting equipment then ask the supplier for advice on the way to fit them.

A public performance was nearly cancelled when the local authority noticed there was no safety chain on the lamps. For each lamp they required a second fixing in the ceiling for a safety chain in case the adjustable fixing of the lamp loosened and allowed the lamp to fall. People worked through the night to fit the chains.

There may be minimum distance between the lamps and ceiling to prevent heat from the lamps damaging the ceiling and creating the hazard of material falling from the ceiling.

 

[Psyclist]

Well he said he doesn't want them to be, but that's what I suspected about the rigging. That's what I've used before when I used to do set building at college, I just didn't know if alternatives were available.

I know exactly what's going to happen. The lights that come will be for rigging installations, and they'll just hand them to me and say "off you go" and when I explain that you need rigging for them, they'll just tell me to do something like take the clamps off and screw whatever I can to the ceiling.

****es me off like. They never do anything properly.

It's like the grit spreader they bought. We've got a huge carpark and 2 miles of road and driveway to grit, so the gardener asked for a grit spreader before it gets cold this year that he can attach to the back of his quad. They bought a cheap plastic thing which holds about one shovel full of grit which looks like it would fall apart when pushed along a smooth tarmac road let alone pulled along behind the quad.

 

[Psyclist]

Nice one. I'll try and play that card about the safety and local authorities.

At the end of the day I don't want to do it, because I don't know what I'm doing with it.

It's not exactly fitting a batten or pendant lamp to the ceiling.

 

[bernardgreen]

Fixing to a joist with wood screws would be high risk as the screws would expand with heat from the lamp and then contract thus becoming loose over time.

Anything like that I would use at least a bolt vertically through the joist with locked nuts. And then only IF the reduction of structural strength in the joist was acceptable. A bracket that went over the joist would the way if it had to be done. And a similar one for the safety chain.

Writing that makes me think about whether the joists will take the weight of the lamp whatever fixing method is used.

And how will they be controlled ? Are the sockets remotely controlled or will it be a man with a long stick operating the switch on the sockets ?

 

[OwainDIYer]

http://www.blue-room.org.uk/ has a sub-forum on lighting for stage etc.

Presumably the hotel owner has ordered lights that can be switched on and off at the mains, and don't rely on DMX control?

 

[ban-all-sheds]

p****s me off like. They never do anything properly.

At the end of the day I don't want to do it, because I don't know what I'm doing with it.

As I recall your employer seems to make a habit of asking you to do things outwith your competence - clearly he doesn't give a stuff about his legal obligations.

 

[ban-all-sheds]

there are 13A sockets on the plastered beams across the ceiling so connection will be fine (provided they come with a 3 pin plug!).

Might they come with a 15A BS 546?

 

[JohnD]

Theatre lights usually do come with a 15A plug, and no means of turning them on/off/dimming because this is done at the supply end of the circuit. And they normally come with a fitting to go on a bar like a scaffold pole. The hire company will usually be able to supply safety chains which must to go round the bar. It would be usual to have a bar and control equipment permanently installed in a building that is used for performances, or at least ring-bolts in the walls and ceilings so one can be affixed. The cables are very prominent.

I am a licence holder for a theatre. Instead of Licencee it is now called DPS ("Designated Premises Supervisor") but this is the person who holds the licence.

I think you might do well to try the local authority licencing office for advice (they need a Premises Licence as well as a Personal Licence for theatrical and similar events), you could even suggest they come out to meet you and your boss, or they might require it, enabling you to say "not my fault." It will be the same licencing office that deals with licences for pubs, clubs and hotels. They usually have an office in the civic offices although technically they are not employed there. They are very hot on breaches of licence conditions, especially safety, and can inspect at any reasonable time and close you down if necessary.

Look on the bright side, if he is the DPS, it will be him that is at risk of losing his licence. It is the same Personal Licence that authorises him to sell drink and late-night refreshments, so if he does lose it, he will no longer be authorised to do his job. If you have your licence revoked it is slow and difficult to get a new one.

The DPS (=licencee) is the Responsible person, and the buck stops with him. He cannot divert or delegate responsibility to anyone else, he remains liable even when he is on holiday, for the actions of his deputy.




p.s. in your position it might be easier to fix the lights to the walls. It is easier to screw and plug if they are brick or block, rather than trying to find a good fixing in a plastered ceiling. They are also less likely to fall off, and if necessary people can get at them with a ladder. The lighting bars can be mounted vertically, as well as the more common horizontal way. You would have to pay more attention to the fixing and safety chains though, so they can't just slide down the bar. I stopped rigging lights before the vertical bars were installed at our theatre, so personally, I only have practical experience of horizontal bars.

Proper theatre bars usually have multiple 15A metalclad sockets fixed to them, with a huge junction box at the end, to reduce the lengths of festooned cable and extensions (which can also fall off), but you can use a plain pole, especially if it is short and adjacent to the supply sockets.

The safety chain needs to go to a very secure fixing, since if a lamp falls off (or more commonly is dropped during handling) it will fall a short distance before pulling up with a snap when it reaches the end of the chain loop. Snap hooks are usually used but must be substantial steel.

The lamps will get extremely hot during use and may be a fire hazard if mounted close to a flammable surface.

 

[bernardgreen]

Look on the bright side, if he is the DPS, it will be him that is at risk of losing his licence. It is the same Personal Licence that authorises him to sell drink and late-night refreshments, so if he does lose it, he will no longer be authorised to do his job.

But beware that the DPS then claims against the person who did the work as instructed without formally informing the DPS that the work as instructed would create a safety hazard.

 

[wermy]

At last an electrical post that I can give some knowledge on.

I did amateur and semi pro in the past and those lights are mighty heavy and take some power. You could be looking at 1KW in just one unit.

As JohnD rightly said they will probably come with an old style 15A round pin plug. They didn't move over to fused 13A standard plugs as changing a fuse 20ft up over the scenery is no fun. You can get proper brackets to mount a plain bar as JohnD mentioned, they are standard fitment either side of the front of a stage.
As they are spots you could be caught between having a good wall fixing and the units being in the right position to light the correct area.

Cheers Alan

 

[Psyclist]

BAS the guy is constantly trying to save money and seems to spend a fortune on trivial stuff like having a load of extra newspapers around the hotel, entertaining his own personal guests at large dinners that he pays thousands for and having expensive soaps and shower gels in the rooms, but when it comes to important stuff like this, he just puts loads of pressure on me to do it as cheaply as possible. At the end of the day, he's my employer and if I constantly dig my heels in and say no I can't do that or no I won't do that I just feel like a spoilt toddler. My last boss was even worse. He used to literally force us to do stuff that wasn't safe by responding to any suggestions or complaints with his favourite "This isn't a f'n sweetshop! If you don't like the job, you know what to do.".

It certainly sounds like the walls are a safer bet for fixings since they're block cavity and the ceiling is not only ornate, but the joists are pretty much inaccessible.

I'm going to send my boss an e-mail and explain to him the problem with the electrical connections which are a potential problem and the risks involved with the mounting of the lights. I'll see what he says.

Cheers guys