'Tab' Curtain

[Ryano]

Hi, I was just wondering if anyone would be able to offer any help with the following:

 

I'm directing a Victorian Melodrama for the Edinburgh Festival this year and it's pretty essential that I have a fully useable (and safe) red curtain (6m x 2.5m).

 

We're in a black box theatre that doesn't have a curtain and so we are resigned to making one that can be erected within the 5 minute get-in time!

 

Our latest idea is to have two vertical parallel scaffold poles weighted at the bottom, with rope suspended between them on top to hang the curtain on. The sides of the curtain would be fastened by velcro onto the poles and also over the suspended rope. A rigging system on the back of the curtain would allow us to pull the curtain tabs open diagonally.

 

A bit like this diagram here:

Tab Curtain:

http://www.sewwhatinc.com/Custom_Sewing/Cu...rtain_Types.htm

 

Does anyone think this is practical, or does anyone have a better way of doing this?

 

Additionally I also need help on how to fireproof the curtains and rope to meet the theatre's safety requirement's.

 

Any thoughts?

 

HELP!

[andy_s]

Fireproofing can be done by using an appropriate solution - Flamebar, or by using inherently flame retardant fabrics in the first place - any theatrical fabrics supplier such as Joels, MacDougals etc would advise.

 

I would expect problems if you stretch a rope between two scaff uprights - you would be surprised how much weight you would need, and you will always have a "sag" in the middle of the rope unless you can tension it off to something really solid and structural. better to use a scaff "goalpost" using allenkey clamps, with a scaff crossbar. You might need to put in some bracing to keep it rigid and stable, but you can certainly achieve a 6 metre span with no sag in the middle like this.

[Bryson]

Glad you're thinking about the fireproofing - I've been one of those Theatre's Production managers, and have merrily applied the practical test for fireproofing on a number of occasions, and have thrown set onto the street when it failed a few times too!

 

A goalpost sounds like the best option to me, too. A rope probably won't cut it.

[Ryano]

Thanks for this guys - such a quick response!

 

My one problem with the 'goalpost' structure is storing a 6m scaff pole! I'm not sure the theatre would have the space.

 

Also, how would the braces on the verticals best be placed to keep it up?

[ChrisD]

Any way you could hang it off truss on winch stands? You'd obviously need to know how to put up truss, probably on 2 winch stands, but truss can be taken apart. Alternatively, use 2 3m scaff poles.

[mac.calder]

Over 6M, your string idea will definatly not float. The goalpost style would work, however I still worry about the length. Is it possible to do suspension? I know in our black box, we do something much like that, and it can be taken down and put up in minutes - although ours is curtain rail. Basically we use 4 fly points about 2m appart on the grid (8m curtain), which are finished with caribenas which hook onto the curtain rail. At the end of the performance, if it needs to come down, it is easily lowered and stored. Next show, bring it out, clip it on, and raise it. As the rigging is done without counterweights or anything like that, it is usually raised by two people, as with all that curtian weight it is damn heavy.

 

Of course you need to make sure everything is done by the book, but it is not something special really. I am unsure about the logistics of it, because I did not do it - it was much before my time. Venue tech says it is safe, so I am assuming that they have had it looked at by pro's.

[Jivemaster]

2.5m wind up stands are trade available or hireable. put a truss adapter on top and fit a beam made of three 2m lengths of 2, 3, ot 4 tube truss add the curtain by positive clips and wind up. All sounds so easy, til you try calculating it, and realise that the stand bases will occupy 1.5m on each side so the curtain opening becomes 6m - 3 m = 3m MAX is that enough. Hava you a big enough team to do the job in the allowed get in time

 

The forces involved in a catenary suspension would be so great as to be un-usable (multi ton balast risking the floor)

[andy_s]

I used to use 6m crossbar / goalposts for black backdrop in non-theatre venues like school halls and village halls - the way to do it is: 2 x uprights to required height (we used to go up to 4m), 1 x 6m cross bar, and 2 x diagonal braces across the corners from upright to cross bar. I'm afraid I'm computer-illiterate (it's my age)and haven't learnt how to do pictures on here, which would make it clearer...

 

the uprights sat on small square plywood bases with a couple of stageweights - footprint of about 450 x450. If using alloy scaff, the whole structure can be easily moved in one piece by two fit people, so you might be able to store it in one piece flat against the back wall.

 

Our version was one side of a three-sided structure to do back and side masking; this meant it was pretty stable - I will even admit to (but not recommend - older and wiser) standing on the inside of the upstage corner leg/brace junction. If you used the back on its own, you would need to use some other form of stabiliser like the outriggers on an access platform or tallie. You could probably run these at 90 degrees to the goalpost, so your opening wouldn't be restricted by the tripod as described in the other post.

 

the only way of doing what you need to do with rope (whether fibre or steel) is to identify two immoveable structures either side of your space, (eg get load tested fixing point rawl-bolted into each wall) and attach your line to them, then use a tensioning device - (could be as simple as a bottlescrew, might need to be a tirfer winch) to get your cord bar-tight. Even then, I'd expect a bit of sag when you add the downward load of the curtain.

 

in another post, there's a description of a tightrope apparatus for Barnum which requires 2 tonnes of ballast. this is not applicable in this example, unless you want someone to walk across the top of it.....

[J Pearce]

At college where they seem to hate the stage but love acting underneath a 2 1/2 metre high balcony, we hang a guaze cloth to close off the balcony above the acting space.

This is hung on steel wire attached to the load tested upright lighting bars. The tensioning is done using a bottle screw. There is a lot of sag on the curtain. If you can hide the sag up in the flys you might get away with it. However, in my experience, a cyc is a lot lighter than black tabs; so I don't know how effective it would be in the OP's situation.

[Jivemaster]

Main tab is usu a very heavy cloth. Try to price and get GROSS weights for some curtains, then see if this weight is within your available load on a 6 m truss.

[Ben...]

You could try something like this; (never tried it myself)

 

http://img278.echo.cx/img278/2351/catenary7yb.png

 

Essentially a suspension bridge-like setup; a (sagging) rope, with a horizontal rope suspended from it using carefully calibrated verticals. The sagging rope doesn't even have to be that taut.

[andy_s]

You could try something like this; (never tried it myself)

 

http://img278.echo.cx/img278/2351/catenary7yb.png

 

Essentially a suspension bridge-like setup; a (sagging) rope, with a horizontal rope suspended from it using carefully calibrated verticals. The sagging rope doesn't even have to be that taut.

<{POST_SNAPBACK}>

 

great idea - should we just call you isembard?

 

seriously though, it would work, but you'd need to take into account quite a lot of variables - the stretch in the verticals, the fact that when the curtains are opened and shut the loading will change. Wouldn't mind trying it out, but perhaps not on 5 minute turnrounds.

[Ben...]

great idea - should we just call you isembard?

Not really my idea, I'd be the first to admit :(

 

seriously though, it would work, but you'd need to take into account quite a lot of variables - the stretch in the verticals, the fact that when the curtains are opened and shut the loading will change. Wouldn't mind trying it out, but perhaps not on 5 minute turnrounds.

<{POST_SNAPBACK}>

Ah, but if you do get it to work then turnaround would be very fast, as the whole thing would be preassembled and you'd just need to attach at four points.

[Jivemaster]

Everything comes down to how much can you do in FIVE minutes, or how many people can you throw at the job, inc how much money can you throw at it. calculate the weights and loadings then calculate the force required to lift the corner of the tab and the load imposed on the support points during the raising of the tab. Can your company afford say six crew just to rig a tab, and can you train them to work well together at speed??

 

Having FSMed long ago at a festival the five minute limit is put there to stop people setting a massive set, as a fast temp rig is sometimes less safe than it could be. We allowed 10 mins to set and five to strike, and a 15 min interval twice in an evening was over-long.