West Texas Sirens Cont'd from Cont'd+New Pics

[Travis]

I noticed from the pictures that the sirens are activated through a dedicated line relay. The phone line has probably long since been disconnected.

Would a wrong number start the siren?
Or must the siren "answer" the phone line and receive a code?

If I am not mistaken, most phone-operated systems require the user to enter a pass code/command code before the device will activate. In other words, you dial the number (123) 456-7890x1234. I've never done it myself, but I assume it's like calling a beeper.

[Thunderboltlover]

That makes sense.

I suppose in severe weather the city could try to send somebody to each siren with a ladder to hit alert on the AR or something, but maybe not.

I know Texas can get plenty of interesting weather, but has Lubbock seen many tornadoes since the t-bolt activation system was destroyed?

Also, do they plan on installing newer sirens?

I doubt it, but maybe they want to put radio DTMF on the t-bolts for emergencies?

[holler]

I noticed from the pictures that the sirens are activated through a dedicated line relay. The phone line has probably long since been disconnected.

Would a wrong number start the siren?
Or must the siren "answer" the phone line and receive a code?

If I am not mistaken, most phone-operated systems require the user to enter a pass code/command code before the device will activate. In other words, you dial the number (123) 456-7890x1234. I've never done it myself, but I assume it's like calling a beeper.

Yes you are correct, partly. The procedure you are referring to involves using a DTMF controller such as a Viking RC3.

With a dedicated trunk line a phone line is pulled all the way from the siren to the activation point, so it can be used for the siren ONLY. Those sirens have the old bells system relays which are basically just a relay and nothing else. Whenever activated the controller (phone companies made variants of them) would send a voltage down the line to the siren relay, causing it to latch, and then relase to cut the siren off. This system could be used to activate a timer at the siren, or to control the siren entirely (the relay would open/shut like a motor starter).

All the Thunderbolts at Robins AFB are controlled with telephone relays activated from a central point. The relays just open and close to control the RCM. Also if you notice the sirens in Lubbock are the same way, they have no AR timers at the sirens themselves, just RCM's which are controlled by the telephone relay.

I have an old western electric relay identical to the one in the lubbock t-bolt pictures. It's basically just a small set of contacts with a DC coil , and uses 20hz power. I've forgotten the exact voltage.

[Robert Gift]

[quote="holler"][quote="SirenkiD"]... If I am not mistaken, most phone-operated systems require the user to enter a pass code/command code before the device will activate. In other words, you dial the number (123) 456-7890x1234. I've never done it myself, but I assume it's like calling a beeper.[/quote]
Yes you are correct, partly. The procedure you are referring to involves using a DTMF controller such as a Viking RC3.

With a dedicated trunk line a phone line is pulled all the way from the siren to the activation point, so it can be used for the siren ONLY. Those sirens have the old bells system relays which are basically just a relay and nothing else. Whenever activated the controller (phone companies made variants of them) would send a voltage down the line to the siren relay, causing it to latch, and then relase to cut the siren off. This system could be used to activate a timer at the siren, or to control the siren entirely (the relay would open/shut like a motor starter).

All the Thunderbolts at Robins AFB are controlled with telephone relays activated from a central point. The relays just open and close to control the RCM.[/quote]What did they do in the 50s and 60s before solid state and DTMF?
Could a wrong number start a siren?
As preteens, my friends and I occasionally heard a loud outdoor bell ring at a tree nursery.
I found the mainumber of the nursery, Example: 364-4400, and dialed 4401, 4402 ...
I recall 4404 set off the outdooringer, which I later dialed at midnight.

[holler]

Robert this WAS the only remote activation system before radio control.

A wrong number could not start the siren if it has a trunk line, since that line goes straight to activation point, and the relay cannot "understand" a phone number, it's just a set of contacts. It relies on the voltage being sent down the line from the controller.

That is the entire purpose of a trunk line, to enable a secure transaction of power from one point to another.

With that being said, some relays were made that fed off the dial tone of the phone ringing. Every time the phone would ring the contacts would close. Adam Pollak knows more about those.

[Trey]

Thunderboltlover, in response to your questions:

They could try to send someone to each siren to activate it, but that would be endangering the lives of the people activating each siren. Plus they don't even know which siren works or if any of them work. A number of things could be wrong with one of them, none of them, or all of them. I think what the city of Lubbock does now is send police cars, ambulances, fire trucks, emergency management vehicles, and probably highway patrol cars out down the streets with all of their lights and sirens blaring. The emergency management also tries to convince the citizens of Lubbock that the best means of notification and warning that you can get for emergency situations is a NOAA weather radio, as well as listening and watching the local media such as radio stations and TV stations.

I am not aware of any serious tornadoes that have been through Lubbock since the siren system was dumped. I'm not even sure when the system was dumped. Lubbock has had several landspouts and funnel clouds over the last few years.

No. Lubbock is planning on using a system similar to Reverse-911. The emergency manager says that a new siren system would be much to expensive to install and maintain. Lubbock has grown tremendously since the Thunderbolts were abandoned, so there would have to be more sirens added.

Again, no. Lubbock has completely broken away from using sirens as any means of public warning, except on emergency vehicles.

[Travis]

I remembered to add the other pics, finally.