“The Federal Signal Thunderbolt siren is one of the most famous ‘older sirens’ in the history of sirens.” Check out the high-low fire signal on this one in Sarnia, ON, one that’s flooded, in Maysville, OK, one on full alert in Seminole, OK, an alternate wail in Saint Paul, NE, an unwell example in Riceville, IA, or watch private owners of various Thunderbolt models test out their siren in the yard, demonstrate the Thunderbolt’s “chopper” levels, the hi-lo solenoid, its “pulse signal,” a decoupled “blower” in action, extra blower action, or dual Thunderbolts in concert.
Civil Defense Museum: The First Siren Project – Federal Thuderbolt 1000 Restoration
Google Maps: Thunderbolt Sirens Still in Existence
Fandom: Thunderbolt Siren Series