For the best resource and final word, join the
NFPA.
Best is a deluge/sprinkler
system, AND a proper active
smoke exhaust
system, and not just
smoke doors on the
grid roof to aid in convention currents (though they may
play a part of a larger, integrated
smoke management
system.)11/21/1980. :
I'm going to disagree with dereks opinion about deluge being preferable over a
fire curtain - IN SOME INSTANCES.
On a typical
proscenium stage with a
fly tower, there are 2 primary things that need to happen to prevent a fire from getting out of
hand: This all was as explained to me, un-officially by a NYC Fire Dept. Inspector who was recommending either a deluge or improvements to our
fire curtain. Note also that the fire prevention systems for non-traditional theaters such as in-the-round, or
thrust stages are a completely different issue.
1) You desire/want to keep the flammable objects on lower levels from having their flames reaching into the fly loft and consuming other flammable objects. Fire and heat want to climb upwards and fly towers are very vulnerable to severe damage during a fire, first at risk is wood scenery and
soft goods, next is the moving elements of the rigging
system, then the actual steel structural
system (think World Trade Center). Thus there is usually present some sort of sprinkler
system located above the
grid system, next to the roof to dampen and slow the on-stage fire. The second part of the on-stage prevention
system is a venting
system to remove gases and heat. Venting systems were traditionally a set of "
smoke" doors usually located in the fly roof and connected to a mechanical heat sensor (fused link) that melted under heat load and triggered a set(s) of spring loaded doors to open. Our theater had it's older mechanical/spring loaded doors replaced at one
point with a similar
system connected to a
smoke detector. Needless to say, theatrical
smoke triggered the roof doors, which is why that
smoke detector was removed More recently, roof venting systems are powered fan systems that can vent the gasses (but not as well the heat) and which are usually powered off the emergency generator
system (if one is installed). Powered venting systems have a
bit of an advantage of not allowing too much air flow (as does the open roof doors) which can actually feed air to the fire, allowing more rapid expansion.
2) The
deluge system is a high powered and very intense curtain of water installed at the
proscenium arch, where the traditional mechanical
fire curtain was installed. The intent is to put up a wall of water that fire, heat and
smoke cannot penetrate.
It does nothing, however to prevent movement of objects -burning scenic flats, as example, from falling
thru the
proscenium towards the audience., and that is the main *conceptual* problem with a deluge curtain, and is why there is now growing pressure on JHA's to reconsider using an actual mechanical "Fibertek" over steel frame style
fire curtain in place of a deluge, in appropriate theaters having fly towers.
Some background to this:
In the mid 70's, as the real estate market in Manhattan - NYC heated up, there was pressure on the owners of theaters containing fly towers to sell their "air rights", I.E. the physical space over the theaters. The NYC building code at the time prevented the usage of air space above theaters with fly towers as it prevented the proper operation of the venting doors.
Thus alternative fire prevention systems were designed, such as the deluge curtain and powered venting systems, which now allowed the air space over a theater to contain office building. Thus was built the Uris (now the Gershwin) Theater, Marriott Marquis, and others. I believe the test case was the American Place Theater on W 46th street, NYC, which is a
proscenium theater with little fly loft. This design forced the architects to create an alternative to a flying
fire curtain, and as there was no fly loft, the
deluge system was used.
Unfortunately, the NYC building and fire codes were changed so that the deluge curtain became the ONLY acceptable method of
blocking smoke, fire and heat at the
proscenium arch.
Recently, a test case as exemption to NYC applicable codes involved the Biltmore Theater on west 47th street, in NYC. This theater was a former Broadway theater that had fallen into dis-use, with the Manhattan Theater Club taking over in 2003 after a major renovation. Part of the renovation included restoration and upgrades to the
fire curtain, in lieu of installing a deluge curtain.
Steve B.