# Fire Curtains & AHJs



## thomp01d (Jun 8, 2014)

Has anyone requested permission from your AHJ to temporarily place a scenic unit on the proscenium smoke pocket line? Asking for context only - I have no plans of actually doing so.

I'm well aware of the codes surrounding fire safety curtains and which are applicable in my jurisdiction (Austin, Texas.) Texas has adopted NFPA 101 (2009) and NFPA 80 by extension. While I am unable to find an exact reference to proscenium fire curtain line obstruction, it is clear throughout the code that it must be able to be operated by one person, be gravity operated in emergencies, make a full seal within a determined time based on height, and have the ability to self deploy based on rapid rise temperatures. NPFA strictly prohibits blocking fire doors and tampering with/preventing safe use of fire protection devices. It also states that the curtain is to be lowered any time the stage is not in use.

Based on what I've dug up, the Authority Having Jurisdiction over local fire code is the only person who can approve this sort of request or interpret the standard. The question is whether it is practicable to approach the AHJ with this type of request, and what kind of processes would have to implemented to gain approval.

I've seen large scale shows that had full-stage plugs for automation decks that filled the smoke pocket - which was approved, platforming with fiberglass skirting (approved), and cables or rugs taped flat. I've also seen automated systems that automatically retract an obstruction when a fire alarm or fire curtain is deployed, or when there is a power outage. (This option is also quite expensive.)

So . . . thoughts?


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## josh88 (Jun 8, 2014)

I haven't, but I've worked with a guy who had a design obstruct the path of the fire curtain and the AHJ approved that. (Though I don't know under what conditions) So the worst thing one could do is ask and get a "no" response. It seems almost nobody in America follows the lowering the curtain each night rule. It's a much more common thing across the pond.


Via tapatalk


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## MNicolai (Jun 8, 2014)

If you're going to make the request, prepare to have something to offer up in lieu of not being able to use the fire curtain. It's one thing to have a mechanism and plan for quickly removing any potential obstacles, or that such obstacles are near the ground level and easily removed by one person (music stands, etc.) -- it's another to put scenery there that would fully prohibit the successful operation of the fire curtain in a way that's not readily correctable at a moment's notice.

Things you could offer AHJ would be a swift, planned execution of removing the obstacles in the event the fire curtain needs to be engaged, and/or additional fire protection measures (everything on stage flame retarded, no potential ignition sources used in props, scenery, effects, etc.).

If what you were going to do was put a scenic flat through the curtain line, you could make a 1' wide plug in it that's somehow either hinged or clipped in between the downstage flats and upstage flats, that would allow that plug to quickly be removed to make way for the fire curtain. The key here would be that the downstage parts of the wall would have to be free-standing from the upstage parts so that the whole scenic wall wouldn't fall over when the plug was removed. Other key would be that the plug could be removed without tools and from ground level (no time to find a drill or ladder in an emergency).

Another route for receiving a green light on this is if the nature of the event renders the fire curtain irrelevant. I've previously gotten an AHJ to allow the fire curtain be obstructed during an event where the audience was seated entirely on the stage. Fire curtain would've provided no protection to audience in the event of a fire. AHJ allowed it after additional exit signs were posted on-stage and our maximum capacity for that event was lowered (something we had to do anyway for practical spacing of the scenery, audience, and performers on-stage).

Of course, the simplest option is to just not obstruct the fire curtain in the first place, but if you're going to do it, get AHJ to approve your request before you're committed to it. Don't wait until the set's already on stage for them to shut you down.

Good rule to follow here being that if you're going to remove one fire protection measure, add in one or several hazard mitigation measures to:

1) Reduce the odds of a fire occurring in the first place, and
2) Reduce the damage a fire can cause to people and property should a fire occur, and
3) Make sure people have enough time to exit in an orderly manner should a fire occur.


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## Robert (Jun 8, 2014)

My experience was to have a method of separating the scenic element at the fire pocket and demonstrate the ability to remove the set piece.


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## Bamalamatx (Mar 24, 2017)

I'm having a hard time finding rules in texas about fire curtains. We are about to start tech for a show and a grand piano is in the line of the fire curtain. I was told that it's fine for the show.. there just needs to be someone, if there is a fire, to move the piano out of the way. That doesn't sound right.. I thought the fire curtain needs to be clear of all obstructions 24/7. We also have smoking onstage, and a permit to do so... just confused with the "gray area" of the fire curtain rules. Help?


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## MNicolai (Mar 24, 2017)

I wouldn't worry about a piano. If you want to be careful, move it out of the line of the curtain between shows. Acquaint your SM or stagehands with the notice to move it if anything happens.

Where you get into serious issues is if you have a 12' tall set piece in the way, that is both tall and not readily movable.

EDIT: Struck ref to chain link bottom finish.


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## BillConnerFASTC (Mar 24, 2017)

What "chain link" in the bottom? Most have a rigid pipe batten in the bottom.


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## porkchop (Mar 24, 2017)

MNicolai said:


> I wouldn't worry about a piano. If you want to be careful, move it out of the line of the curtain between shows. Acquaint your SM or stagehands with the notice to move it if anything happens. Wouldn't be ideal, but if the curtain was deployed for any reason, the chain link bottom would contour around the piano for the most part. Some smoke would get through the open area below the piano but it would be the equivalent opening size of an open doorway.
> 
> Also, the nature by which smoke propagates, it will rise up and fill the fly loft and build a layer of heavy smoke that will lower down toward the ground level as the volume of smoke in the fly loft increases. This is the same reason that in a fire, you should get down on your hands and knees. At standing height you may be blinded by smoke, but at 18" off of the floor you have a fair chance of having some visibility. An opening in the smoke curtain between the fly loft and the seating area would fundamentally be more compromising at a higher elevation than at ground level.
> 
> Where you get into serious issues is if you have a 12' tall set piece in the way, that is both tall and not readily movable. The curtain will contour around the set piece as best as gravity and the chain pocket will let it, but is going to snag on that set piece so drastically that it will leave a massive area open that will allow smoke from on-stage into the theater.


I have never worked with a fire curtain of this description. The whole point is for it to be a relatively solid barrier. A loose chain able to contour around a piano could create a high velocity path for fresh air that could make the fire worse. A similar situation happens fairly frequently when people that leave the door to a fireplace cracked and the high speed oxygenated air causes a chimney fire.


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## MNicolai (Mar 24, 2017)

Guess that was just my theater. Same one that had smoke pockets on the plans but none were installed.


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## BillConnerFASTC (Mar 25, 2017)

porkchop said:


> I have never worked with a fire curtain of this description. The whole point is for it to be a relatively solid barrier. A loose chain able to contour around a piano could create a high velocity path for fresh air that could make the fire worse. A similar situation happens fairly frequently when people that leave the door to a fireplace cracked and the high speed oxygenated air causes a chimney fire.


You don't really believe that a fire safety curtain ever kept air from a stage fire do you? You simply can't seal a room as large as a stage to ever starve a stage fire, nor would you want to. Much better to let it draft and raise the neutral pressure plane as high as possible.


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## porkchop (Mar 25, 2017)

seal it completely, no of course not. But a piano shaped air channel would be no one's friend.


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## BillConnerFASTC (Mar 25, 2017)

I was at a conference in London - 1992 I think - SAFE-Theatre '92 maybe? - and listened to a fire protection person talk about fire curtains and making the point they should stop several feet above the floor or have large holes in the bottom to assure that air is drawn from the auditorium and allowed to feed the fire and assure it drafts through the roof vents and doesn't bank with the smoke layer getting lower to the point it can billow out through the proscenium opening. Kind of proven by the point the curtain has never done much in real stage fires and the vents have been shown to be very effective. Besides, I don't think there is a fire curtain in this country that would withstand the pressures of a real fire. It would bow in so far to the stage and lift so far off the ground the air would thankfully be sucked under. That is what in fact happened at the The Empire Palace Theatre Fire, 1911. Survivors reported the fire curtain do not close but everyone got out just fine. Other reports from that fire are the basis for our codes yet today, in particular the design concept of 3 min 20 sec for egress. The 20 minute fire door is sometimes justified by that because it's a design factor of 6.

Hopefully fire curtains will be eliminated from the codes someday entirely before many more decades.


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## porkchop (Mar 25, 2017)

Interesting, guess it's a good thing the giant monstrosity of concrete and metal at the Aria never had to be used.


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## RonHebbard (Mar 25, 2017)

BillConnerFASTC said:


> I was at a conference in London - 1992 I think - SAFE-Theatre '92 maybe? - and listened to a fire protection person talk about fire curtains and making the point they should stop several feet above the floor or have large holes in the bottom to assure that air is drawn from the auditorium and allowed to feed the fire and assure it drafts through the roof vents and doesn't bank with the smoke layer getting lower to the point it can billow out through the proscenium opening. Kind of proven by the point the curtain has never done much in real stage fires and the vents have been shown to be very effective. Besides, I don't think there is a fire curtain in this country that would withstand the pressures of a real fire. It would bow in so far to the stage and lift so far off the ground the air would thankfully be sucked under. That is what in fact happened at the The Empire Palace Theatre Fire, 1911. Survivors reported the fire curtain do not close but everyone got out just fine. Other reports from that fire are the basis for our codes yet today, in particular the design concept of 3 min 20 sec for egress. The 20 minute fire door is sometimes justified by that because it's a design factor of 6.
> 
> Hopefully fire curtains will be eliminated from the codes someday entirely before many more decades.


@BillConnerFASTC; Would you care to comment on deluge curtains like the one in NYC that inadvertently flooded a theater renovation project shortly prior to completion? (Approx. very early 90's) I'd also like to learn more of the "Music Box" fire in 1990 where dimmer racks rained down from just below the grid when non fire-rated spansets melted. I believe it was the fire that caused fire-rated spansets to be mandated and rules like spansets being allowed during hoisting operations but having to be sistered / replaced by GAC once in position. (Maggie Smith and Maggie Tyzack [Sp?] were starring in "Lettice & Lovage" and I believe they only lost one performance then continued their sold out run under essentially work-light lighting.)
Toodleoo!
Ron Hebbard.


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## BillConnerFASTC (Mar 25, 2017)

I suspect the flood was the Joyce. No fire an no one hurt. For some reason iirc there was no alarm and water ran all weekend. Not the only such incident - none on my projects.

Considering that in the past 100+ years the idea of separating stage from auditorium has not resulted in one verified incident of saving a life or reducing injury, but several injuries and much property damage from the curtain and deluge system, all the more reason to get rid of it.

No recollection of the spanset incident.


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## RonHebbard (Mar 25, 2017)

BillConnerFASTC said:


> I suspect the flood was the Joyce. No fire an no one hurt. For some reason iirc there was no alarm and water ran all weekend. Not the only such incident - none on my projects.
> 
> Considering that in the past 100+ years the idea of separating stage from auditorium has not resulted in one verified incident of saving a life or reducing injury, but several injuries and much property damage from the curtain and deluge system, all the more reason to get rid of it.
> 
> No recollection of the spanset incident.


We, most of our crew, were hanging around the stage door of the Shubert when the sirens came screaming up and acrid black smoke was billowing out of the lobby entrance to the Music Box just around the corner. The FDNY were extremely upset to find 48 and 96 way touring racks plummeting down through the dense smoke from just below grid level. I honestly believe this is when the FDNY decreed normal, non fire-rated, slings could no longer be used to support things like dimmer racks and chain motors on an essentially permanent basis. I believe they were still allowed to be utilized for hoisting of loads and gripping of bundles of Socapex (6 way) and Pyle-National (12 way) cables but only for the actual hoisting. Once in position, I believe they had to be sistered, and / or replaced, by fire rated GAC-Flex and / or GAC slings. I'm pretty sure this was the event that brought about their revised decrees. As I wrote previously, I believe the sold out run continued in the foul smelling, poorly lit, theater with only a single performance cancelled. This would have been in the fall of 1990.
Toodleoo!
Ron Hebbard.


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## Footer (Mar 25, 2017)

Every venue I have been in within the last few years that has a deluge system has had it accidentally tripped at least once. 

Back to the OP, our general rule for this type of thing is things can reside in the fire pocket. However, every night the pocket is cleared. Also, I don't like to see anything over a foot or two tall (wedge, pedal board) in the spot where our wall is I also don't allow anyone to setup a position where someone will be standing under our firewall all night. So, no podiums or micstands that place a singer right under it. I also don't allow anything structual (truss) or anything that takes more than one person to move. Thats what works for me and our AHJ. Every night the fireline is cleared and the wall is brought in. I would not leave the venue with anything in the fireline. I have had a fusible link fail and it brought in our firewall. I have also had the "cut here" rope fail as well. Luckly both times both of my firewalls were closed so no one was hurt.


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## SteveB (Mar 26, 2017)

BillConnerFASTC said:


> Besides, I don't think there is a fire curtain in this country that would withstand the pressures of a real fire. s.



Our fire curtain might be the exception.

2 layers of Fibertex (spelling ?) on a steel frame about a foot thick, travelling inside a L/R vertical pocket.

As to deluge, the Joyce system has gone off at least twice that I know of. Kimmel center in Phiily once, plus Kingsborough Community College (CUNY) in Brooklyn (80's). The last went off on a Friday (they think) and as the sprinkler system had no flow sensors tied into the main security annunciator panel, nobody knew till they discovered it Sunday morning. Or so I was told. BIG mess.


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## BillConnerFASTC (Mar 26, 2017)

Seems like examples of poor design. The fusible link and cut line failure sure seems like too much tension on that system. Sounds like a manual overbalance system, and why new ones are required to be motorized. Gets past the BS of weights dropping on weights, etc.
And I wonder if the deluge systems mentioned were designed using pre-action, where there is an alarm and a short window of opportunity to abort. Missing that and the notification so it runs all weekend are both unfortunate design flaws.


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## Footer (Mar 26, 2017)

SteveB said:


> Our fire curtain might be the exception.
> 
> 2 layers of Fibertex (spelling ?) on a steel frame about a foot thick, travelling inside a L/R vertical pocket.
> 
> As to deluge, the Joyce system has gone off at least twice that I know of. Kimmel center in Phiily once, plus Kingsborough Community College (CUNY) in Brooklyn (80's). The last went off on a Friday (they think) and as the sprinkler system had no flow sensors tied into the main security annunciator panel, nobody knew till they discovered it Sunday morning. Or so I was told. BIG mess.



Thats what mine is too. Steel framed, DS is wood matching our proscenium walls. Upstage is Zetex. In between is solid plate steel. the whole thing weighs about 14 tons. 

@BillConnerFASTC , this wall was (and still is) motorized. There was roughly 40# on the release line. Without that much the clutch would not throw. 1960's design... really really large motor and clutch. 

Its now all been replaced with a Clancy system. Dash pot was removed... motor was replaced... cut line replaced with pin release.... etc.


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## SteveB (Mar 26, 2017)

Footer, thanks, ours is Zetex as I recall.

Ours is a also a mid-50's design, counterweighted and motorized, with a leaking and now deactivated motor. Thus it stays out - hopefully. as otherwise no way to raise it. 

As we are currently going through spasms of updates to the assorted fire alarm systems, they are planning a motor replacement with trip mechanism tied into the alarm system, so as to bring all up to code. 

Fortunately the engineers fully understand that the curtain is much preferable to a deluge. We are on edge about this as there's seemingly a NYC code that declares that if the distance from floor to bottom of a certain grid point is less then 50 ft, out comes the curtain, in goes the deluge, which is what they did on our smaller space next door getting renovated. That space had a grid the same height as the larger hall, thus we pray and give sacrifices weekly to the alarm gods.


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## RonHebbard (Mar 26, 2017)

Footer said:


> Thats what mine is too. Steel framed, DS is wood matching our proscenium walls. Upstage is Zetex. In between is solid plate steel. the whole thing weighs about 14 tons.
> 
> @BillConnerFASTC , this wall was (and still is) motorized. There was roughly 40# on the release line. Without that much the clutch would not throw. 1960's design... really really large motor and clutch.
> 
> Its now all been replaced with a Clancy system. Dash pot was removed... motor was replaced... cut line replaced with pin release.... etc.


In Hamilton, Ontario, Canada, The Russel Johnson / Artec designed "Great Hall" opened. The 17,800 pound counter-weighted matching faced acoustic wall was steel faced on the U/S side and immediately behind it was the 11,000 pound asbestos fire curtain. 
The drive for the acoustic wall was at grid level DSL and the drive for the fire curtain at grid level DSR. This was in the fall of 1973 when the motor drives weren't soft-starts and the grid flexed scarily when the drives were energized. 17,800 pounds of acoustic wall with 17,800 pounds of counter-weights divided equally on either side of the prosc' left and right. Similarly for the asbestos with half of its counter-weights on either side. They both remained in service for many years before their supporting sheaves required replacement. When it was time to replace the sheaves, the wall was brought in to its low trim with its seal compressed on the deck and two very large scissor lifts were rented, one SR and the other SL so the counter-weights could be transferred from their arbors and stored on the scissor lifts while the sheaves were replaced. I'm unsure of the present status of the asbestos curtain. I know at one point it was entirely painted with two coats of a transparent sealant but it may have been totally replaced by now.
The acoustic wall and fire curtain ran in separate vertical slots. When both were in to deck level, and the double-width person-doors were closed on SR and SL, we could load in and hang a multi-trailer road show backstage with neither our activities disturbing a full symphony rehearsal out on the two fore-stage lifts nor the symphony folks disturbing us. (Other than the muso's kept wanting our coffee, and for free. The nerve of those A.F. of M'ers!
Toodleoo!
Ron Hebbard.


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## Tom Andrews (Mar 27, 2017)

SteveB: re the NYC code for fire cutain vs deluge, talk to Marymount Manhattan College theater. Their grid is around 30' or 35'. They have a braille fire curtain. I think distance from top of proscenium to grid is about 12' or so. If there's a 50' rule for the grid height (which sounds odd), this could be an example of an exception.


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## BillConnerFASTC (Mar 27, 2017)

It looks like NYC has adopted the IBC and amended these requirements, changing 50' to 40' as the criteria for separating stage from auditorium, as well as limiting the options for how that separation can be achieved. Keep in mind the 50' or 40' is to the deck above, not the gridiron.


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## Tom Andrews (Mar 27, 2017)

Thanks, Bill. Can you refer us to the appropriate Chapter and Section? I'm more familiar with FC than BC.


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## BillConnerFASTC (Mar 27, 2017)

4.10 iirc. I only googled it this morning. No NYC work in my experience and not an expert on NYC code. Around page 22 of this:
https://www1.nyc.gov/assets/buildin...tailed_Requirements.pdf&section=conscode_2014


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## SteveB (Mar 27, 2017)

Thanks for that link Bill.

From what I read, if the grid deck is less than 40 ft above stage deck, deluge is required, If over 40 ft. can be curtain or deluge. Our stage deck to grid deck is about 44 ft. 

Which begs the question as to why ARUP opted to go with a deluge, replacing a steel framed, double walled fire curtain, on the adjacent space being renovated. I suspect it was cost, in that they would have needed to do much work to renovate and bring up to code the existing curtain, or they might have needed to replace entirely. They opted deluge, telling us the code said the stage didn't have the height. As well the stage is getting a monstrous winched and flying acoustical shell located at the proscenium, functioning like a large garage door. It's huge and heavy and is located right where the fire curtain used to be.

Mind that these decisions were about 8 years ago and I've no clue when the NYC code might have changed.


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## Footer (Mar 27, 2017)

SteveB said:


> Thanks for that link Bill.
> 
> From what I read, if the grid deck is less than 40 ft above stage deck, deluge is required, If over 40 ft. can be curtain or deluge. Our stage deck to grid deck is about 44 ft.
> 
> ...



Your sister school Hostos up in the Bronx also has a deluge... and it has gone off at least twice since install from what the guys there told me. Both times were due to alarm tests gone wrong.


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## BillConnerFASTC (Mar 27, 2017)

SteveB said:


> Thanks for that link Bill.
> 
> From what I read, if the grid deck is less than 40 ft above stage deck, deluge is required, If over 40 ft. can be curtain or deluge. Our stage deck to grid deck is about 44 ft.
> 
> ...


As I read it and as it is written in the IBC, over 40' (or 50' outside NYC) you have to have a fire safety curtain OR a deluge system aka water curtain.

The measurement of height does not involve the grid. It's to the roof deck - to the metal deck typically when there is just a roof - or to the same deck that is a floor deck when there are rooms above the stage. It's a volume limit, not flying or anything else. I suppose if the roof sits on your loft block beams, and you consider the roof beams your grid, ok, same. I've just never considered roof framing that blocks are clamped to a grid.


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## egilson1 (Mar 27, 2017)

I'm trying to dig up some notes on a fire model ARUP did a few years ago about this topic. I know based on those models they made several recommendations for updates to NFPA 80. I'll see what I can find. 

Ethan


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## MNicolai (Mar 27, 2017)

@egilson1, is this what you're looking for?


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## SteveB (Mar 27, 2017)

Footer said:


> Your sister school Hostos up in the Bronx also has a deluge... and it has gone off at least twice since install from what the guys there told me. Both times were due to alarm tests gone wrong.



I'll bet that sucked. 

Our public safety department has no clue how the centralized alarm system works. We've had 2 small fires in our building this past month, caused by the steam fitters welding pipes (no comment). In both cases the PS Dept. Did get the building cleared (there was obvious smoke), but could not clear the detector nor silence alarm. Our PM knew where the button was. You think that after the first time they would learn something.


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## SteveB (Mar 27, 2017)

BillConnerFASTC said:


> As I read it and as it is written in the IBC, over 40' (or 50' outside NYC) you have to have a fire safety curtain OR a deluge system aka water curtain.
> 
> The measurement of height does not involve the grid. It's to the roof deck - to the metal deck typically when there is just a roof - or to the same deck that is a floor deck when there are rooms above the stage. It's a volume limit, not flying or anything else. I suppose if the roof sits on your loft block beams, and you consider the roof beams your grid, ok, same. I've just never considered roof framing that blocks are clamped to a grid.



Got it. In our case it'll be the original roof deck (the roof essentially). That's well over 50 ft. from stage deck. Might be a volume problem though as they did make the existing stage smaller by installing a new wall for a hallway on SL, cut the wing space by 15 ft. Not sure if it's under the 1000 sq. ft. limit.


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## egilson1 (Mar 27, 2017)

MNicolai said:


> @egilson1, is this what you're looking for?



Close, but no. This was done after that document was published.


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## BillConnerFASTC (Mar 27, 2017)

IIRC without looking, the only change, for which the Arup report was some of the substantiation, was elimination of the fusible links.

As the proponent of the FPRF research project, I don't feel the Arup report met the purpose or answered the questions. I don't recall any other changes in the 15 or so years I've been on the NFPA80 committee.


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## RonHebbard (Mar 27, 2017)

SteveB said:


> I'll bet that sucked.
> 
> Our public safety department has no clue how the centralized alarm system works. We've had 2 small fires in our building this past month, caused by the steam fitters welding pipes (no comment). In both cases the PS Dept. Did get the building cleared (there was obvious smoke), but could not clear the detector nor silence alarm. Our PM knew where the button was. You think that after the first time they would learn something.


@SteveB Your optimism is refreshing.
Toodleoo!
Ron Hebbard.


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