Another SONGS Model 120, taken during the day.
The SoCal Edison Model 120 was a siren that was designed by SONGS audio engineer John Glenn Powell and some sound engineers at San Onofre, specifically for use at the San Onofre Nuclear Generating Station. Produced from 1982 until 1988, these sirens were meant to supplement and partially replace SONGS' system Sentry sirens and Federal Signal STL-10s, as neither proved to be as effective as they were claimed to be, and SONGS wanted a siren that would meet their specific needs.
The Model 120 is a Supercharged Eletromechanical siren, getting most of its power from a large 10HP centrifugal blower located beneath the horns. Utilizing a 4-port chopper with an 8-port stator, this siren has a deep sound to it that's unlike any other siren. Interestingly, the siren only uses a 2HP motor, as it gets most of its power from the blower. Unfortunately, no recordings exist of a fully assembled Model 120 running, so it is unknown exactly what it would sound like. It was rated for 120db at 100 feet, at 240/480hz depending on if the blower was on or not. The Model 120 Stator had narrow holes making it, Pneumatic!
The Model 120 performed adequately for over 23 years, but time was not kind to them. Age and significant rust took their toll on these sirens due to their proximity to the ocean, and unfortunately they, along with most of the Federal STL-10s, were removed in Late 2005 To Early 2006 and replaced by a system of Whelen WPS-2810 and 2806 omnidirectional electronic sirens, which were then removed after SONGS decommissioned!
These sirens are often mistaken for a "Toshiba" siren, as the siren model was unknown until information was received from Powell himself. The siren is NOT made by Toshiba.
One single incomplete Model 120 is left in existence, in the hands of a private collector. The siren had never been installed and was in storage as a spare, and every single other Model 120 was confirmed to have been scrapped after their removal in Late 2005.
A SoCal Edison Model 120 with its horns removed, giving a better view of its centrifugal blower.