Lighting pipes

[Jim Hill]

I am looking into the possibility of rigging some pipes in our auditorium for lighting our stage. I was wondering what the ideal specification for the actual pipes would be? Also, do people prefer a series of short pipes angled towards the stage, or a couple of full length pipes paralel to the stage.

 

(At the moment we have the equivalent of a girder in place and we can only put lights where the bolt holes are present, so it isn't very flexible.)

[dunk_1984]

I assume by "pipes" you are referring to scaff(old) bars?

 

I don't know about the configuration of these however depending on the situation and the load people would rig either scaff bars or truss capable of supporting the load you plan on hanging from it.

[paulears]

As a point - 'bar' as a term is mainly just us in the UK - overseas, 'pipe is more common. One train of thought says it gos back to the days when gas pipe was pretty common, and of course, here in the UK we decided 'gas barrel' was a much better term, so from time to time, you could even hear bars called barrels.

 

If you have a girder, and this is going to support the pipe - then I guess it's simplest to have the pipes follow the girder line. If you have the choice, then a series of shorter bars, facing the stage tend to allow the highest density when you need to squeeze an extra light in. One long bar, is much easier to install - and means spacings can be more versatile. So I don't think it really matters that much. For me, FOH, the only thing that would make me decide is ease of focussing. How do you get up there? A fixed, rigid long bar that can have ladder access with hooks is much nicer than an A-frame or other system that has to be manhandled around?

[tokm]

At the moment we have the equivalent of a girder in place and we can only put lights where the bolt holes are present, so it isn't very flexible.

Bolt holes?? You saying they've drilled bolt holes through the beam? If so.. well.. I'd suggest you get it checked by a structural engineer before anythings rigged off it permanently..

 

In regards to the bar arrangement, I'd second Paul's suggestion of having multiple shorter bars, much more usable than one long one.

 

Tom

[Jim Hill]

The girder isn't structural, it's hanging as well. I'll be getting rid of it when I put the pipe(s) up.

 

I'm just wondering about the specs of the steel bar. Say I put up a 6.5 m bar, would I need 32mm or 40mm (bore size) with 3mm wall or stronger? I'm more concerned about flex. Even 32mm steel pipe will be plenty strong enough. I'll also be looking for pipe clamps (maybe called bar clamps in the UK?) for fixing the lighting fixtures. Anyone know where I can source these, I'm in Australia.

[paulears]

Unless they do things very differently in Australia, then inch, or inch and a half diameter isn't good enough (and to be honest - never ever has been) 48mm o.d. is pretty well the only standard. I've been to a few places where they have used 50mm thin wall tube, and apart from bending - it won't fit most clamps - 4mm is a lot! Steel? thick wall ali is more common.

 

I suspect we are all thinking girder=I Beam, and you wouldn't have one of these suspended for anything other than structural reasons - I'm thinking maybe somebody needed to hang TONS, not Kgs off it. What exactly is this thing then?

[david.elsbury]

The clamps are often called hook clamps. Try calling your local lighting seller, or one of the major companies like Bytecraft or Chameleon, or LSC should be able to point you in the right direction.

 

 

http://mejor.com.au/store/images/hookclamp.jpg

[Roderick]

You could try Herkes is Sydney - Herkes

Or Stage & Studio - Stage & Studio

 

But there will be Queensland resellers for these too, search for Doughty, Manfrotto, Penn Fabrication to name a few.

And as David suggested, check with the lighting suppliers, the company where you buy your gels and lamps will most likely have these too.

 

Standard pipe size is 48mm - 50mm with 3-4mm wall. Think scaff pipe and you are pretty much there!

You could go with a different size but that would make the future use of the bars extremely difficult if you wanted to hire some additional equipment, which will come with standard hook clamps.

[Don Allen]

The ideal lighting bar in Australia is 48mm thick wall aluminium pipe. If you use 50mm you will have trouble with some brands of hook clamps not fitting over the bar. Access to the lighting bar for focussing may determine where it ends up, but the ideal position is determined by standing in the centre of your downstage area and looking up at 45 degrees to see where the bar is optimally located. (using the Mcandless method of keylighting).

 

You need to be aware of your states regulations on rigging and safe working at heights.

[Jim Hill]

48mm, 3mm wall. Thanks. I'll get some quotes, and thanks for the info on the clamps.

 

The girder is a typical case, in amateur theatre, of someone thinking that something that is free is good enough.

 

A steel pipe is cheap and far easier to handle. Aluminium, I suspect, will be expensive, but I'll look into it.

 

Counterweight is the next radical idea I need to bring to these people.

[IJWesley]

48mm, 3mm wall. Thanks. I'll get some quotes, and thanks for the info on the clamps.

 

A steel pipe is cheap and far easier to handle. Aluminium, I suspect, will be expensive, but I'll look into it.

 

We have just replaced our main bar in our church (in Sydney) and went for aluminuim tube (48mm, 3mm wall). AU$60 for 6.5m length (contact Caprol aluminium).

 

We fixed it into position using clamps from Ezystrut

 

Ian

 

Edit - should be Capral, and their distributor is Smart Aluminium

[Jim Hill]

Brilliant. Thank you Ian.