A Lot of Excitement over a Little Haze


Hi all,

At my school last night we were performing the last show of a Broadway musical and dance revue show. It was pretty cool, because every act was tied into New York City in some way. The second half was set in a night club, so we got a really good deal and rented a hazer to give just the right smoky effect. The show was in our black box theatre, so we placed the hazer on our tension wire grid and allowed the haze to sink down toward the stage. Through the course of tech week we figured out that it took about 1 and a half minutes of running the hazer during intermission to produce a nice relatively dense haze that lasted the entirety of the second act.

I was the sound designer, and having nothing to do during the show, was house managing. We were running the hazer when the fire alarm went off. The front of house staff jumped into action. I got on the radio to tell the stage manager to hit the panic button on the house light panel and to evacuate the cast. I (along with the other usher) started yelling to the audience to move towards the fire exits camly. We helped the senior citizens in the audience get out safely and then we hauled ourselves out. Once outside we were joined by my school's public safety department who helped us to hold the crowd on the far side of the road until the fire trucks came. In a few minutes we managed to explain to the firemen that it was a haze machine that had caused all the smoke and not a fire. After checking out the grid they deemed the hazer to be the cause and left.

Public safety and the fire chief both congratulated us on how well we handled the evacuation.

So, first of all, this gives everybody an idea of how important it is to have properly trained front of house staff even if (like in our case) they are just volunteers.

It also raises the question of whether the manufacturer lies when it says that a diffusion hazer cannot set off smoke detectors. It was the detector right above the area of the grid that had the hazer that tripped. The really odd thing was that we had been running the hazer in the same manner each night for a week of tech rehearsals and for two other shows and had not tripped the fire alarm. Does anybody have any other experiences with fire alarms and haze machines?

I've never seen any atmospheric generator that guarantees it won't set off alarms. There are too many variables, such as type of fluid used, area, type of detectors, USER ERROR (not to say you were in error). Hazers are TYPICALLY more forgiving, but if you get enough particulate in an area, and the sensors are particulate detectors, they will trigger.

I've triggered alarms. Once, we had were in an old gym with a stage. So we started pre-show music, had a moving light grid on stage and fogged out the whole stage area with the curtain closed. Idea being that we'd open the curtains and a rush of fog would envelop the dance floor. The light guy got a little aggressive (I couldn't see my hand in front of my face) and we triggered the alarms. But I didn't know because the music was too loud. Anyway, the alarms were cleared by the school staff and it was no big deal. Oh, the effect was very cool, btw.
len mentioned type of fluid as having a role in determining if a hazer will set off fire alarms, does anyone know what types of fluid will and what wont?
None, AFter having the audt, that i work at being rewired for fire alarm systems 3 times. you have to know the limits of your place. Unfortunatly, after dicussiono with the disctrict, my school has a complete ban of all smoke machines, hase, or even excessive dust in the air.

Just last week the fire alarms went off because someone sprayed dry erase board cleaner.

The only way to deal with the issue is to call up the fire dept, and see if you can make special arrangments. Usually they are pretty nice.
well, it's ghetto, but at one place where we sometimes use fog, we turn off all the AC systems for a whle before and after. That way the detectors in the AC unit don't go off.
We just put on Jesus Christ Superstar. Before the first act we fogged the stage so when the curtain opened there would be a rush of fog. This all worked out great. About a 1/2 hour later our fire alarms went off. Eveyone evacuated and our local FD came and they said the problem was with heat sensors in the boys locker room. Apparently the Lacrosse team had left two showers on and the steam had triggered a heat sensor. It is amazing how quick rummors spread around school. The other lighting designer and I have heard everything that we lit a fire, we were pulling a false alarm, and our fog set the fire alarms off. People just don't get it, we were at the lighting board for at least an hour before the alarms went off. The fog had dissipated 20 minutes before the alarms. Rummors spread like wildfire at my school!!!!
Well was my fun weekend with my fog machines!!
Another thing to consider is that the temperature in a theatre (any confined space) will increase as the room fills with people. As the temperature rises, it is conceivable that the smoke/haze will also rise (remember convection currents).

Therefore, in rehearsals the concentration of smoke at the detector may not have been enough to trigger an alarm but when the theatre filled with people, the smoke could raise higher due to this increase in temp.

It is not uncommon for aerosol cans to set them off either. The hospital where I use to work had alarms triggered in the past when the cleaners sprayed air freshener too close to the sensors.

I think that the fluid reference may have been in relation to using fluid in a machine that has not been recommended by the manufacturer.
A theatre i have done work for in the past has a system where they can deactivate the smoke detectors on stage and an overhead laser in the auditorium, and also the sounders. the rest of the building has the standard stuff active minus sounders but all areas, tech booth, sm desk, dressing rooms, and foh areas have red zenon beacons ( not auditorium ) so as not to panic the punters and so they can do some investigation before evacuation is needed. they are also hooked up to the firebrigade so they are called automaticaly. and all of this is in an amature venue, a converted church of all places. http://toadstheatre.co.uk.
Welcome abourd RedEyeProd. I see that your theatre is in Torquay - just down the road from Faulty Towers perhaps? Nice looking theatre by the way. How are the acoustics in there?

I notice that you also have a cinema - is that set up in the same space as the theatre or is it separate? Saw a show on TV when I was in the UK last month and there seemed to be a fairly strong resurgence of the smaller cinemas (2 or 3 viewing rooms) in some of the smaller cities and towns, which were managing to compete with the larger complexes in the bigger towns and cities.

A couple of those on the show actually had the main cinema stage used for theatre productions and hired out the smaller “intimate” cinemas (20 seats or so) as recording studio space. The aim was to have as many people doing as many things as possible to ensure that the space was not idle and therefore the profit was better.

It was interesting and I wonder if you are doing something similar?

A lot of venues here have a similar set up and many have a delay, which allows an "all clear" to be reported before the alarms actually go of.
sort of OT, but once the fire alarm (one of several, or something like that...basically, a loud beeping noise that stayed on for several second, every few seconds, like 30...) got knocked on by someone and the person with the keys to the setup room was out of town, and no one could find the keys. So it stayed on for days. we called the fire people and explained, then proceeded to be annoyed by beeping....
In reply to Mayhem, yes the theatre is about 2 mins drive away from the hotel that faulty towers was based on.

the acoustics are rubbish for speach but great for music.

the cinema is once a month at the moment we only have one screen that is on the front counterweight and flown in as needed we also used it when we did an adaptation of midsummer nights dream where film was a key theme, we had gone with the wind playing before act 1 as the audience entered.

the auditorium seats approx 230 so no safty curtain is required ( 500+ seats in uk ) but the tabs are soaked in flamebar so we close those in emergency.
we have a full lx rig with a strand 520i controling 73 channels of dimming including 1 for houselights. we also have a reasonable sound rig for basic sound reinforcement (1200w) but if we want to do somthing more meaty we usualy hire in.

Here are some piccies of some of our work


Communicating Doors
Lester said:
My theatre is also outfitted with a pre-recorded female voice that instructs everyone that an emergency has occured in the building and an evac is needed. It goes through the sound system speakers as well as all monitors. We have audible and visual alarms even in the auditorium, which I think is safest.

Do you have any idea how this is wired in? I have to assume that it is right before the amps in the signal chain. Can you shed any more light on this one?
The panel that controls it is on the SM console. It 'takes control'. I think it acts as a mic input, but it somehow bypasses the sound board, because there is a preset volume control for the 'Emergency Announce System'. The levels on the sound board cannot control it. Not sure how it works but the voice is preceded by a 'dial-up' sound. It seems to be routed through an assembly mixer. If the sound system is not on, the system will not announce, only the sirens will sound. There is a 'panic' button that will also activate the voice should we know of the problem before it is automatically detected by the system. The announcement is universal, so it could be used in any situation where the building needs evacuation (such as carbon monoxide, bomb threat, etc). I'll look at it tomorrow, and look through the sound system diagrams and see if I can learn more about it.
The building it is installed in is the Campus Theatre (www.campustheatre.com)
I do know that the main Fire Control/Communicator panel has the name Silent Knight Fire Systems on it.
The Evacuation Annunciator seems to work similarly to the Audience Recall Chime, except it sounds through all speakers including the ones in the grids of the hallways/offices.
We had asimilar situaltion in our thetre, only it turned out osmeone had been smoking a joint immediately outsidethe air intake for the building.

Fortunately we hada similarly well trined FOH crew, aswell as techs, so the evac was quite hitchless.

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