Fun fact: despite the videos claiming the sirens were broken, they actually weren’t. The sirens (Federal Signal Modulators) were performing the Alternate Wail signal, a combination of the Wail and Hi-Lo signals. All Federal Signal electronic speaker sirens can perform this signal, as well as the mechanical Thunderbolt 1003 and 3T22 sirens also made by the same company. Chicago sadly switched to the standard Wail signal years back.
Fun fact: despite the videos claiming the sirens were broken, they actually weren’t. The sirens (Federal Signal Modulators) were performing the Alternate Wail signal, a combination of the Wail and Hi-Lo signals. All Federal Signal electronic speaker sirens can perform this signal, as well as the mechanical Thunderbolt 1003 and 3T22 sirens also made by the same company. Chicago sadly switched to the standard Wail signal years back.