Sloped Nonfixed Obstruction at Platform

[dbill74]

I am looking at a situation where I have a performance "platform" (NOT a stage) with sound deflectors that will be moveable in the vertical plane. The deflectors constructed so as to be at 2 angles, 12 degrees and 32 degrees, with no means of retaining heat from a fire.

http://files.engineering.com/getfil...0&file=Platform_FP_working_file_Model_(1).pdf

shows a section through the deflectors.

In plan view the deflectors are approx 7'6"x7'6".
Is it worth trying to get sprinklers into the deflectors per NFPA 13 8.6.5.3? 8.6.5.3.3 would seem to allow me not to have them in the deflectors since the deflectors are not "fixed".

I am open to suggestions for protecting under the defelctors.
Thanks in advance.
Bill McDonald, PE

 

[cdafd]

any way to use a row of sidewalls underneath them??? maybe if they are in a wall??? and shoot under the deflectors???


add addtional lines at the deck level to possibly get distrbution depending on the angle of the panels??

a head between the panels??? at panel level

extended coverage heads???

seems like you need something

 

[dbill74]

Had already looked at and ruled out sidewalls. 1) platform is approx 40'X60' with no proscenium, even with EC heads, there will be a lack of coverage front and center. 2) Sound deflectors are ~3' from any wall and at highest set-point the widewalls would be several feet below main ceiling (code max is 6").

Heads between panels is something I am keeping in my back pocket; they would require a pre-action system and possibly other controls to "reset" the deflectors to their high point in the event of a fire.

 

[cdafd]

Had already looked at and ruled out sidewalls. 1) platform is approx 40'X60' with no proscenium, even with EC heads, there will be a lack of coverage front and center. 2) Sound deflectors are ~3' from any wall and at highest set-point the widewalls would be several feet below main ceiling (code max is 6").

could you put a little structural projection to act as a heat collector, not wild about it but somethin as you would find in a laundry chute.

why do you need the pre action if you put them between the panels???

 

[chevy4x4trucks]

Any chance they could be hung with a solderlink on one side so that in a fire the low side would release and they would become vertical? They look like they will be well above people in the room so you would have the head room for it. In this case they would no longer be an obstruction.

 

[dbill74]

Both ideas are great, but the swinging panels idea has already be nixed by the architect, and the baffles/draft stop would need to be applied to all panels including the front ones by the audience (doubt the architect will buy into it).

The Pre-action system would be needed for sprinklers between the panels for the same reason I need a draft-stop or heat collector. Heat/smoke detectors at the primary ceiling would activate the pre-action sprinklers.

Would there be any code issues with protecting the platform like a stage (this is not a stage) with a standpipe system and hose valves at the platform level?

 

[cdafd]

Still not sure on how the panels work or look like in different posititons


I guess my idea was to put sprinkler heads between the panels, at even to the bottom of them. and if they are in some other position the ceiling heads would activate and cover between the panels.

do not see a need for pre action and even with pre action you have to have the heat, at the head, to activate the head.

 

[dbill74]

What is not clear in the file attached to my original post is the fact that these panels are not continuous across the entire width of the platform. So when I talk about heads being between panels I am thinking between adjacent panels along the width of the platform. As for other positions, the panels are moving vertically only, no horizontal movement, no rotation.

You are right about needing heat for preaction, my thoughts were more along the lines of a deluge type system.

Thanks for the feedback.
Bill

 

[cdafd]

Not sure if a flex head would work, not sure how much vertical movement the panels will have or how much movement the flex heads could take.

interesting problem

can they seperate the panels enough to allow the the ceilings to protect them

or require say beam detectors below the panels to alert that there is a problem???

or tie the panel conteols in so in case of any fire alarm that they move to a certain postion and the head is in a loction to catch the heat????

 

[dbill74]

FlexHeads won't work. The maximum length of flexible pipe manufactured is 6', these panels will be moving as much as 20' (to floor level) for access to lighting. This does not concern me greatly at this point as I have devised a means to allow the piping to move with the panels.

Regardless of the spacing between the panels, they are still big enough to be obstructions.

I am not familiar with "beam detectors". How would these work?

Using the controls to move the panels to a "fire alart position" could work.......locate sprinklers between panels, then need way to entrain heat to avoid use of deluge sprinklers.

 

[cdafd]

Suggest consulting with and FPE on this


Normaly beams are used to cover a large area, like an atrium or other large open areas instead of using smoke detectors, which would take more, and if fifty feet in the air may not work , and also yearly testing is a problem.

beam shoot a beam to a reciever and if obscrued by a per cenatage of say smoke they activate the alarm.

you can but them at various levels as needed.

http://www.systemsensoreurope.com/English/Guides/Beam_application_guide.pdf

http://www.systemsensor.com/pdf/A05-0095.pdf

sounds like if you can pull the panels up upon fire alarma activation and provide protection below, would be the best bet. You are relying on mechanical means to make the system work, and also yearly inspections to assure it continues to work.