World Trade Center Fire Alarm System History

Voice evac panels that would have been in the twin towers pre 1993





All of these are cpv-90s which would have most likely been in the twin towers before 1993. These panels piggybacked off an xl3/system 3. The cpv-90 was basically the pre mxl-v released in 1984. And also the 9/11 pa message video actually used this tone on the fire panel: Pyrotronics CPV-90? - #2 by randomperson this message is the same message that the cpv-90 uses.

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According to the very first post in this topic the WTC’s original system was an “American Multiplex”: as far as anyone knows Cerberus Pyrotronics did not become involved panel-wise until 1993 when the system was upgraded.

But it says the building contained a pyrotronics cr-7 system though we don’t know much about the cr-7 I remember finding out somewhere that the cr-7/xl-3 are the panels that the cpv-90 piggybacked off of

The system pre 1993 could have been a mix between the mxl and the cpv-90 with the mxl being the majority

Oh yeah, didn’t see that, sorry.

Its fine heheh we all forget things

I don’t know if this video is too well known. But it’s possible that wtc 7 used paging speakers for audible notification like in this Building.

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Execpt there was a chime

It’s semi-well known going by the comments on the video (the original may not have gotten much attention but now that it’s been reuploaded more people have likely seen it now that they’re aware of its existence to begin with).

Could have considering the original pre-1993 WTC 1 & 2 system used bullhorn-type speakers (at least if that’s what you mean by “paging speakers”).

Yeah, which according to what others have said is used to notify building occupants that the fire department has been notified: the reason it might not be sounding on the above system could be due to several reasons, including the feature being disabled (if it’s possible to do so on the 8500 at least), the system not being connected to the FD & thus having no reason to sound the chime, it not having notified the FD at that point in the video, etc.

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Yes that is what I meant by paging speakers

image

RE

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wtc 7 has a wheelock e50/e60
E50H24MCWFW_R

Screenshot 2024-10-30 231219

That looks like a yellowed E-50.

That’s the alarms in the new WTC 7 after September 11th 2001

What exit Signs are at the WTC?

In the photos information it’s dated September 9 2011

wait someone said old wtc 7 uses the e50/e60

and a atlas speaker too