Siren photos currently on eBay

[Daniel]

If they used standard motors, the pitch would be like a Toshiba siren on 60 Hz., or one octave lower than a Model 5.

I read that these sirens were to be mounted on the San Francisco-Oakland Bay Bridge for marine use. Since the bridge is five miles long, I wonder if any of them are still there. Perhaps on Treasure Island there may be a location.