Screen Rigging

[Beautiful_Creep]

I'm trying to investigate different ways of erecting a screen for an outdoor film screening. Last year it was steel scaff, and was a complete nightmare - the screen was attached on the groung and it took 40 people to get it up on the structure. (and it almost blew over and squashed people). The option we're looking at most is currently aluminium truss - at least for the screen 'frame', since it will presumably be much lighter than last year, so it can be assembled on the ground, then raised up (by a few less people, hopefully!) We could try and erect the whole thing out of truss, or use steel scaff for the support frame - we'll need weight somewhere, to hold the thing down, but I'm still worried about people working with heavy scaff, and at heights and things.

 

The structure basically needs to be standalone (its in the middle of a field), big enough and strong enough to support an 8x4m screen, and not move, blow over, etc.

 

Any ideas or help anyone can offer will be greatly appreciated!!!

[David]

a quick google came up with

 

http://www.wedgwood-group.com/projector_sc...ble_screens.htm

[Ynot]

I'm trying to investigate different ways of erecting a screen for an outdoor film screening.

Personally, considering the number of risks you're running with this (which to your credit you seem to have recognised some of them) your best bet is to look closely at engaging a professional team for this one.

 

Don't have a contact, I'm afraid, but this isn't something I'd expect to be tackled by anyone without the due experience/kit/tools etc

 

TD

[gareth]

No matter what you build the frame out of, a screen outdoors is effectively a big sail - it'll catch any breeze that comes its way. A perforated screen would reduce that a bit, but you can't have too many perforations otherwise you'll loose reflectivity. I think your main consideration need to be guy ropes and stabilisation. Having said that, I'm not a 'proper' rigger and I'm just speculating. We do have a couple of proper riggers kicking around on the BR - I'm sure one of them will be along in a minute with some good advice!

 

Have you thought about an inflatable screen? I seem to remember reading an article (possibly in L&SI) a while ago about a company that rents out large inflatable outdoor projection screens - they looked quite good. Can't remember the name of the company, though ...

[Beautiful_Creep]

Have you thought about an inflatable screen? I seem to remember reading an article (possibly in L&SI) a while ago about a company that rents out large inflatable outdoor projection screens - they looked quite good. Can't remember the name of the company, though ...

 

Perhaps I should have mentioned we have a budget for the entire event of £2,000, and a large portion of that goes on projector hire, generators etc. I'm reluctant to leave it to an external company since a) we have some experience in this area, and its kind of related to what we do as a society, and b) we probably can't afford it and c) I like to know what I'm getting in to. The screen we have is a high density tarp - last year we used ropes and water to weight it down and hold the whole structure in place ...

[zonino]

unfortunately "we probably can't afford it" isn't an argument for the HSE!

[Ynot]

Perhaps I should have mentioned we have a budget for the entire event of £2,000, and a large portion of that goes on projector hire, generators etc. I'm reluctant to leave it to an external company since a) we have some experience in this area, and its kind of related to what we do as a society, and b) we probably can't afford it and c) I like to know what I'm getting in to. The screen we have is a high density tarp - last year we used ropes and water to weight it down and hold the whole structure in place ...

Sorry, but your reluctance won't hold any sway with the authorities if there are any problems at all with your construction!

Safety at this sort of event is PARAMOUNT and with the litigiousness of today's society, you'd be well advised to make the safety of this screen your FIRST priority!

As I see it, the screen is going to be the NUMBER ONE risk on your list of possible problems, and the one with the highest probabilty of causing serious injury or even fatality should winds pick up.

Just because "It worked last year" is also not going to cut the mustard with the AHJ, because that may have been due to luck rather than judgment.

 

Sorry to sound like we're coming down hard on you on this one, but, well, ...... No - actually, I'm not sorry, because this NEEDS to be sorted properly - the genny fails, the projector fails, or some such like, and the audience don't get to see the movie. But if the wind blows down your big screen with scaff poles sailing in the air, people are going to get HURT. Simple as that.

 

Your statement that "a) we have some experience in this area" again is NOT enough to satisfy the HSE unless that experience can be backed up with training and qualifications. It's one thing sticking up a screen in the back yard for mates, but another entirely when you erect a large construction for the public.

 

I'm assuming you have full PLI for the event, yes?

Are they aware of the method of constructing the screen?

Have they had opportunity to pass your plans?

I suspect they MAY have something to say about it if you don't have this erected by professionals, to be honest.

it's always wise to run anything unusual past the insurers, just in case - I do, and have on occasion either had a risk added to the policy or cancelled/modified plans according to their responses.

[Beautiful_Creep]

OK, I need to get one thing clear which is : I am not an idiot!

 

I accept that there will be issues with this whole thing, but right now my problem is simple: I can't judge the problems for myself, because no one is willing to simply and clearly explain how such a system would work, the potential problems involved etc. This was my intention in asking this forum - NOT to be told yet again to go and sit in the corner like a good girl.

 

I have no intention of endangering anyone, but nor do I intend to throw away money on a system I do not understand, all I want to know is *hypothetically* what the best way to go about it would be. Even if we got an external company to rig this for us (which is the most likely option) we would still need to have some say in the design, what the structure was made of - we certainly wouldn't just leave it to them to do whatever the hell they liked.

 

So yes, health and safety is important (thanks all the above) and is being addressed, but I would also like to understand a little bit more about the actual systems involved so I can make an educated decision about what to do ...

[bruce]

OK, I need to get one thing clear which is : I am not an idiot!

 

I don't think anyone is suggesting that you are :)

 

We're just saying "tread carefully" - which you appear to be doing.

 

I can understand why this post rang a few alarm bells for people - you say

I'm reluctant to leave it to an external company since a) we have some experience in this area, and its kind of related to what we do as a society

, but you also say

last year....it took 40 people to get it up on the structure. (and it almost blew over and squashed people)

 

This is one area where you really need to get formal advice from the pros, not from an internet forum. Yes, we do have rigging pros here, and I'm sure they'll be along shortly to add some pearls of wisdom, but that's not formal professional advice, m'lud.

 

My suggestion would be to speak with some rigging companies - or even scaffolding people - see what sort of solutions they propose, and then come back here and discuss the options.

[Stuart91]

One approach I have heard of (but not tried myself) is hiring a suitable sized truck, and finding a way to fix the screen to the side of it. I think the theory is that if the wind is strong enough to blow the truck over, it's time to go home anyway.

[Pete McCrea]

First off, at that screen size I assume you have a fialry gruffty projector coming in. I'd be intrigued to know the spec, out of curiosity really.

 

Next- the screen. At 8mx4m your looking at a near house sized screen area. If the wind is to pick up, then your looking at a big wind load. It would be hard to secure a fabric surface against any movement even a ripple with slight breeze, yet alone a full on wind. It will take a Rigging or Enginneering Company to take the windloading factors from the relevant British Standard (BS6399-2 IIRC from my Uni days.), and then design a structure that will be able to take this.

 

I would suggest that should a structure be erected and not designed correctly, IF there were any problems, then those involved could be facing criminal proceedings. By involving a Person with the competency to design this, you would assist in making sure that you are protected as far as possible. I'm not sure how things have proceeded in the case of the Inflatable that blew away, but I know I would be very carefull designing and implemening any type of structure of this nature, especially where the public are involved. Also worth a look at what happens when it goes wrong is the LED Screen in Birmingham. Thankfully no one was hurt in this instance.

 

I'd have thought that something such as a truss goal post system might be one option. These can be suitably ballasted to take LED screens, but you could easilly be looking at £2k for the design and implementation of this sort of structure. I'm sure they'd be more than happy to involve you in the design and implementation, but this sort of structure is the domain of the Engineering and rigging companies with the relevant experience and appropriate insurance.

[tom w]

In brief;

1 Ascertain local wind speeds for the area in question.

2 Calculate implied load, both prevailing and gusting, on screen.

3 From implied load calculate required kentledge (ballast) required. Include safety factor for local conditions, time of year etc.

4 Construct base structure, apply ballast, add screen support structure.

 

Even people who do this for a living get it wrong sometimes... http://news.bbc.co.uk/1/hi/england/west_midlands/5099236.stm

We outsource steps 1 to 3 to professionals to avoid any problems. No one is patronising you Beautiful_Creep. None of us can afford to get this wrong, and we spend a lot of money on getting it right.

Oops. Belt and braces there Pete, better twice than not at all eh

[Matt-onstage]

try this company http://www.purplecinema.co.uk/

 

they are the guys supplying the screens for the cinema field at glastonbury this year and have for a very long time. they have a very large screen and also some smaller ones, give them a call and see what they say.

 

matt

[Ynot]

OK, I need to get one thing clear which is : I am not an idiot!

Didn't say that... :)

but right now my problem is simple:

With respect, is isn't really that simple... because...

I can't judge the problems for myself,

no one is willing to simply and clearly explain how such a system would work, the potential problems involved etc.

There is unfortunately no way that you'll get a better answer than you've had, because this is a public forum, and you're asking for advice from people who don't know you, your site nor your specs. The issue can only be resolved by a competent trained professional visiting site.

This was my intention in asking this forum - NOT to be told yet again to go and sit in the corner like a good girl.

Apologies if that's how it sounded, but it's really not like that!

nor do I intend to throw away money on a system I do not understand, all I want to know is *hypothetically* what the best way to go about it would be. Even if we got an external company to rig this for us (which is the most likely option) we would still need to have some say in the design, what the structure was made of - we certainly wouldn't just leave it to them to do whatever the hell they liked.

This suggests you don't have faith in the pro's giving you the proper advice.

I'd hazard a guess that the pro riggers here will only give you a general idea, and would NOT make any firm statements - hypothetically or otherwise. But you may find a couple who'd be willing to pay you a visit in their professional capacity for solid feedback.

I would also like to understand a little bit more about the actual systems involved so I can make an educated decision about what to do ...

Which is great - but you can't really get a good idea from speculation over the 'net.

I'll stick to my original statement - get the pro's in - in fact if you can, get three different companies in for a quote and go with your best (not always cheapest) option available.

 

Oh - by the way - welcome to the Blue room! ;)

[trussmonkey_2]

As a rigger who has erected outdoor screens in the past,I would strongly advise you to talk to a rigging company about what you want to do. You could try any of the following;- Nick Brown Rigging Consultancy, Nippy Industries Ltd, Unusual Rigging Ltd. I have erected screens with all 3 companies and I'm sure that any one of them would be happy to talk to you to discuss your needs.