Fire Alarm

[jerekb]

So we are having a haunted house in our auditorium to raise money. In this we have a fog machine in the pit and then last night me, in all my brilliance decided to put one in the house. As the people walked through the fog they carried it to the back of the house where it caught an ungodly draft and was carried straight up right in front of me on the balcony and right into the rafters . We were in the middle of discussing the possibility of the fire alarm going off when sure enough, they went off. As there was only 2 groups remaining we went a head and called it a night after the FD cleared the building. So today during second period we had a fire drill. What a coincidence.

 

[willbb123]

I work in an old theater that has burnt down once. So the theater has "a highly sensitive fire alarm system" I like to use haze for every concert that I can. We have to make sure that we get water based haze because mineral based will set of the alarm.

 

[TheDonkey]

Overall, fog nor haze should set off most alarms, most of them actuallt look for the chemicals in smoke, so fog machines only set off the Optical ones, which apparently aren't overly used.

But yeah, having to shut down for a fog machine is a terrible thing, we were doing a haunted house in my schools drama studio and luckily didn't set off any alarms, but after 3 hours the fog got so thick it refused to air out in the 5 minute intermissions we had every half hour. So the graveyard effect we had going where fog oozes up from behind gravestones didn't look quite right.

 

[2damax]

How would you go about shuting off the fire alarms for a theatre. If you have a simplex fire alarm system. the fire alarm goes off from haze and fog.

 

[coldnorth57]

You can NOT shut off the fire alarm EVER in a theatre, BUt you can check out fire alarm system that do not use smoke to check for fire but uses heat

 

[avkid]

How would you go about shuting off the fire alarms for a theatre. If you have a simplex fire alarm system.

An administrator would need to talk to the fire marshal and Simplex.

You would most likely need to have the fire marshal or a representative of the fire department present when the system is off.

 

[GreyWyvern]

An administrator would need to talk to the fire marshal and Simplex.

You would most likely need to have the fire marshal or a representative of the fire department present when the system is off.

Having worked with pyro effects on tour, I know there are certain procedures that need to be followed if a fire alarm system needs to be shut off. Usually, there does need to be someone from the fire department there the entire time the system is shut off, and typically the entire building has to be walked and every room checked every half hour or so. However, codes and regulations and restrictions vary from state to state and country to country, so check with your local authorities.

 

[Balo]

We have a simplex(far from simple) system in our theatre. The Facilities Engineers worked out a bypass with the Fire Marshall that disables the smoke sensors and not the heat sensors in our system for 1 hour to allow the use of smoke effects. We can reset it every hour, but that also ensures that someone is in the building when the smoke effects are in use. The most recent addition to our bypass is the need to call our public safety office to let them also know we're bypassing the system or they send 2 officers to investigate.

There are ways around them, you just have to check with your fire marshall and see what he's willing to do because smoke effects aren't going away any time soon.

 

[Sony]

At my old High School they had a system where they could turn off the detectors but leave all the pull stations active so if someone saw a fire they could still sound the alarm. Unfortunately at the high school I work at and the college I go to this isn't possible and they both use Optical sensors which means we can't used water or mineral based fog at all...

The High school I work at has all of the detectors in the ventilation system, we have no visible detectors. They are Laser type detectors where if anything disturbs the lasers (smoke or fog) the alarm goes off. The return vents are in the front of the apron of the stage so any smoke or haze on stage immediately gets sucked into the return vents and activates the alarm...it's a horrible design for a theatre.

My college has optical smoke detectors in the ceiling and it's a very small space so there is no NOT getting the smoke into them...it's annoying. Luckly at my college they are in the process of installing a brand new fire system in the building...hopefully the new system wont be so sensitive.

 

[TimMiller]

I hate laser sensors. I once set one off at a church by climbing up on a ladder to change a bulb. What a PITA, you have to call the Fire Dept every time you change a light bulb to come out a disable the system, could it get any more stupid.

 

[WestlakeTech]

Before our Fine Arts Facility went under construction, we would regularly rent it out. A small handful of students would run the shows for $10/hr. About a year (maybe year and a half) ago, one of our regular renters, a dance school, was putting on a performance. It was either the first or second time to perform, when in the middle of track 7 the fire alarm goes off.

We evacuate EVERYONE! That's over 1000 people when you add up crowd and dancers. So the fire department shows up (being a school, they're immediately and automatically alerted when any of our alarms sound) and take a look at things. Turns out to be a false alarm and we continue the show once everybody gets back in the FAF.

So it's all over, right?... Nope. 7 or 8 tracks later, alarm goes off again. Facilities Director said one of the alarms in another part of the school was broken, but that was thankfully the last time the alarm would go off that night. In fact, I haven't heard it since. However, we have had an "In case the fire alarm goes off" talking-to at almost every show since then.

One of those moments you hate at the time but you look back on and laugh eventually.

 

[renegadeblack]

Does anyone else see the irony in hoping that new fire alarms will be less sensitive?

 

[willbb123]

They dont have to be less sensitive. they just have to be more intelligent, to be able to tell the difference between haze and fire.

 

[Sony]

there are some really intelligent ones nowadays that can actually sense the ionization of air that happens just before a fire ignites...of course that would mean no more fire or pyrotechnics on stage ether. That and they are incredibly expensive...mostly used in Datacenters and Stuff like that.

I don't think there will ever be a perfect solution other then being able to turn off certain zones. I personally like the idea of being to turn the detectors off and leaving the pull stations active. If that means having one person near a pull station at all times on fire alarm duty then so be it.

 

[WestlakeTech]

Lucky for us, both of our pull stations (one in each wing) have fusable links which any fire will melt causing the curtain to drop. So even if no one's there, we're not completely up the creek. But I do still like the idea of someone always being there just in case.

 

[Sony]

At MVPAC we were supposed to have a system that automatically dropped the fire curtain anytime the alarms went off. However that system was never completed because the fire alarm system is connected to the same system as the high school which has a false alarm pretty much every week. So now it's just a Fuseable Link system. We were also supposed to have a douser bar connected to the sprinkler system but that was never finished...

 

[TRRHINO]

Overall, fog nor haze should set off most alarms, most of them actuallt look for the chemicals in smoke, so fog machines only set off the Optical ones, which apparently aren't overly used.

I would have to disagree... We have tried everything in our theatre. It seems the best way to not make the fire alarm go off is to just cover it with a plastic cup with some good old gaff tape around it... Works like a charm every time... (we have smoke detectors not optical)

 

[Anonymous067]

I have a question:

In our theater, backstage left and right, we have a little glass box that says "break glass and pull in case of fire". But its not a pull-station, (theres those right next to it), and a cable is attached to it going up into the flys. What does this do?

 

[maccalder]

Eeegads... You should never ever ever ever ever cover sensors with a plastic cup. Frankly, if there is not a proper procedure for isolation of smoke detectors (ionisation/optical sensors are the ones you need to isolate), then I am sorry, but you should not be using atmospherics.

There are a number of different types of fires sensors - and each one is optomised for certain things (there are also hybrid sensors which contain a mixture of the lot). The four main types you will run into are Particle(Ionisation), Optical, Heat, Rate of Rise

Only two of these will be set off by atmospherics - the particle (ionisation) and optical sensors. Ionisation will detect any ionised particles caused by combusion and the other two rely on heat. Now the issue with RoR and Heat is that in a venue with high ceilings (think theatre) heat based sensors which are normally installed in the ceiling take a good while to go off (RoR less than Heat).

Ionisation alarms are the type normally found in homes and are prone to false alarm - most venues with decent fire prevention systems will not use these.

Basically a decent venue will use a combination of optical and either RoR or Heat, and will have a FCP somewhere where the optical sensors can be deactivated or put into a non-alarm state of some description. If your local authority finds covered detectors, then someones head WILL roll.

 

[elite1trek]

I have a question:

In our theater, backstage left and right, we have a little glass box that says "break glass and pull in case of fire". But its not a pull-station, (theres those right next to it), and a cable is attached to it going up into the flys. What does this do?

This is probably the release for a fire curtain.

By pulling that, you would release a curtain that will come in, most likely directly US from the proscenium. The fire curtain is designed to keep fire and heat (and sometimes smoke) from spreading into the house from the stage, or vice-versa, in the event of a fire.