Tech / Help

Trenton’s Chrysler air raid siren comes down

These photos were provided by a plant worker; the photographer is unknown, but we will happily provide credit when possible.

The Chrysler Air Raid siren was produced during World War II, a product of Chrysler Industrial, reportedly designed by Bell Labs; the idea was to either frighten or deafen enemy troops. It was the loudest continuous noise ever to be mechanically created (save for its V-8 successor), capable of instantly damaging unprotected ears. Properly positioned far from any individuals, the siren was used as a civil defense warning for tornados and other impending disasters, with the first installation in New York City in 1942; Detroit, Chicago, Los Angeles, Miami, and Seattle put in more than one siren.

The 1951-1957 version used a 180 horsepower Chrysler Industrial V-8 engine, a Hemi design; it weighed around 5,000 pounds, and was over 11 feet long, 5 feet tall, and nearly 5 feet wide. It was completely self-contained, not requiring any functional public utilities. This version drove a three-stage compressor that blew 2,610 cubic feet of air per minute into a siren rotor, where it was sent out through six horns at around 400 mph, produced 170 decibels at the siren’s throat. The unit was designed to rotate at around 1.5 rpm on its base, with a range of 30-50 miles and a 70 dB signal for two miles.

In 1958, one air raid siren was placed on the roof of the Trenton Engine plant; another, on a 90 foot tower off King Road, west of Fort Street, in Trenton, Michigan. The city’s engineering department worked with Dunn & Shankus to install the siren and tower; the siren itself was, according ot Chrysler, built in 1956.

Many of the air raid sirens were, after their working lifespan ended during the 1970s, purchased and dis-assembled for their engines to be used in hot rods or to be broken down into parts. A few were acquired and restored, including one of the sirens from Trenton, which was taken down in 2002, restored, and placed in the Walter P. Chrysler Museum’s permanent collection in 2006. For more on the sirens, see VictorySiren.com