J. Marcoz Emergency Vehicle | Federal SD10 Warning Siren Refurbishment

This siren, a Federal Signal model SD10, was originally installed at the height of the Cold War in the 1950s as part of a Civil Defense warning system. A pair of sirens, one at each fire hall in East McKeesport, served two purposes- first, to alert firefighters that there was a fire call and second, to warn residents of impending Communist air raids. Thankfully they were never used for the latter.

The siren at #2 fire hall was last repaired and repainted in the early 1970s and had been faithfully serving for nearly 30 years. But by late 2000, it had been sounding like a sick cow, belying its proud history. So the decision was made to take it down from its tower and repair it.

Here, the siren lies in the back of the fire hall garage, waiting to be disassembled and repaired.

Look closely and you can see a bullet hole in the siren, compliments of an irate neighbor and his rifle. Even though he scored a direct hit, the siren mechanism was undamaged and continued to annoy him for many years to come.

The siren was repaired and refurbished by Jim Marcoz, owner of J. Marcoz Emergency Vehicle of North Versailles, PA.

These shots show the interior of the siren, the "stator", which produces the sound. By looking at the spacing of the holes, you can see that this siren produces two different tones to form a deep, rich harmonious sound.

A crack had formed in the lower motor housing which threw the entire mechanism off balance, causing the rotor to scrape the stator during operation. The housing was repaired and Jim devised a system to set the rotor-to-stator clearance.

Here we see that the motor and stator have been reassembled, and both it and the siren housing are in the process of being painted.

A new audiovisual warning system was designed and installed by J. Marcoz Emergency Vehicle that, when the siren is activated, turns on the lights in the garage and the parking lot, illuminating the area for the safety of the responding firefighters. A strobe light on the front of the building is also activated to warn passersby to be on the alert for exiting fire equipment.

In this picture, the siren has been reassembled and will soon be receiving its final coat of paint.

A big surprise is in store for airplane and helicopter pilots flying over the station!

The siren was remounted on August 12, 2001 and blew for its first fire call within 3 hours of being reactivated.

For more information on having your siren repaired or refurbished, contact J. Marcoz Emergency Vehicle at 412-816-2320.