Here's an SD-10B that used to be part of Cincinnati Ohio's old system. It's located at US-50 and River Road by a park. It's got the bigger Federal Logo on it, leading me to believe it was installed in the 1970's.

Here's a really old image of the San Francisco Ferry building Heath siren in 1945. An electrician was working on it at that time. Holy cow! I didn't even know that another photo of the siren still in good shape existed, let alone a close up! Where did you find this photo? The only photo of this Hea...

Here's another image of the Ferry Building Heath siren from the San Francisco Library Archive:

My apologies, I did not mean to triple post.

Here's a really old image of the San Francisco Ferry building Heath siren in 1945. An electrician was working on it at that time.

Hamilton OH's Tunnelbolt on Gersam Avenue. I touched the blower box on this one.

A little bit of an update for those interested: Harveysburg's 4/5 Thunderbolt 1000T got a new blower motor and works fine. The blower was reported to not be working properly in January. Correct me if I'm wrong, but I believe Mr. Werden fixed the 1000T. He's fixed those ThunderBolts up there several ...

Usually you must do 2 things before doing this: 1. Inform your local sheriff's department or police department and ask for permission. State that you will only sound the siren during tests or actual emergencies, no in between. 2. Inform the EMA and tell them you will be sounding the siren on test da...

One ASC T128 from 4 miles away. They really pack a punch in terms of output.

In comparison, the 2001's near me can barely be heard from 2 miles away.

Reverse wired means that the electrical leads on the blower have reversed polarity, causing the blower to suck instead of blow.This greatly reduces the original output. When a Thunderbolt blower is reversed, the air will still go to the horn. But, the siren will be much higher pitched. The sound out...