Federal Signal Twinsonic
The Federal Signal Twinsonic was a very popular lightbar through the mid-80's. It was one of the very first "fully enclosed" lightbars. Lightbars prior to the Twinsonic (such as the FS Visi-a-Bar) were composed of two beacons and a siren, a single beacon, or a varation of that theme. Below are two examples of the Federal Signal Twinsonic, it's has been replaced in almost all law enforcement applications as it qualifies for "Flying Brick" status, and was known to cut as much as 5-10mph of the top speed of a vehicle. Although this bar is still popular with small volunteer fire departments, and EMS units.
Bay Village, Ohio Police Department
Dodge Ram Van -- No Longer in Service
Photo by the webmaster
San Diego, California Police Department
1990 Ford Crown Victoria K-9 Unit
Photo by Tony Zelijnak Ofc San Diego P.D.