>Date: Thu, 21 Sep 95 15:37:04 EDT >From: Tony Harminc >Newsgroups: comp.dcom.telecom >Subject: Pole Mounted City Fire Alarm Boxes >Approved: telecom@eecs.nwu.edu >X-Telecom-Digest: Volume 15, Issue 398, Message 8 of 12 Martin McCormick wrote: [Fire alarms boxes that pulsed out their location] > The alarm boxes vanished from streets in Tulsa and Oklahoma > City as well as many other places as soon as 911 became the method of > choice to report emergencies. I also remember that many of the street > boxes had a glass window that one had to break with an attached hammer > to activate the alarm. This always seemed dumb and dangerous to me, > but I am sure there was a good reason for it. Even today many fire alarm pull handles have a glass strip or other device that doesn't automatically reset itself. It's to ensure that misuse can be punished: there can be no excuses like "I was just looking at it to see how it worked, and I accidently set it off". You have to take a very positive action to give the alarm. It (the dangling handle and/or broken glass) also makes it obvious to the repair/inspection people that the unit has been set off and needs work. Toronto lost its pole-mounted fire alarm boxes as recently as 1980, as I remember. There are still a few poles with strips of red paint around them to be found. One point that has perhaps not been made clear is the reason these boxes had clockwork code senders in the first place: they were all connected in parallel on the same wire. (Well, there were subsets, of course, but typically all the boxes that rang in one station were on one line.) If each box had had a direct wire back to the station there would have been no need for pulses and clockwork. As I remember, the wires on the Toronto poles were very thick -- perhaps 10 gauge or thicker. These wires were strung on the municipally owned Hydro (electric power) poles and not on telephone poles. I have no idea what voltage was used. Tony Harminc