Chrysler Put A Hemi In What...?

So…you think you know your Chrysler history… and you can name every application Chrysler ever put a Hemi engine into. Well I got one I bet you never heard of. Chrysler like most automotive companies secured contracts during World War II to build tanks, airplanes, as well as guns and ammunition. Chrysler was no different than all the rest with one exception, the air raid siren. Chrysler earned the distinction during the war years of building the loudest most powerful warning device ever built. No company before or since has built anything like it.

Development of what would be later became known as the Chrysler Air Raid siren was started in January 1942. First attempts were built at the request of the Office of Civil Defense in Washington D.C.

The E.D.Bullard Company of San Francisco designed an engine driven centrifugal siren and submitted it for testing and certification. Chrysler got involved in part because the centrifugal engine driven siren offered by the Dullard company used their Flathead six-cylinder engine to power the siren. Despite extensive tests and modifications, the Bullard-design centrifugal siren could not produce the necessary volume of sound.

In earlier research, the Office of Civil Defense in Washington D. C. had determined that a minimum of 120 to 140 decibels of sound pressure at 100 feet, was the minimum requirement output for a warning siren. With the failure of the Bullard Company siren to meet the specifications, Chrysler was invited to a meeting in Washington D C, along with a few of the sound engineers from Bell Laboratories, to work on the problem and come up with a solution.

With Harry Fletcher of Bell Labs in charge, the engineers at Bell Labs went to work. This resulted a few months later, in the introduction of "Big Bertha" a huge centrifugal engine driven siren one of the largest ever built up to that time. The Bell Labs siren and was capable of 134 decibels of sound at a range of 100 feet. Now that the Bell siren design was proven successful, the Bell engineers drew up a series of specifications, using "Big Bertha" as a guideline, Chrysler was then awarded a contract to build the Bell designed and engineered air raid warning sirens.

The first version became known as the Chrysler-Bell Victory Siren. This first, siren, had a somewhat crude unrefined appearance, Despite its looks, it became certified by the Office of Civil Defense in March of 1942. One hundred twenty of these "Victory Sirens" were sold to 28 different cities among them New York City who bought (10) copies. The city of Detroit bought (20), as did the city of Chicago.

The Victory sirens sold for the tidy sum of $3,760 each in 1942 wartime dollars and were powered by a Chrysler straight -eight 324 cubic-inch engine that was rated at 140 HP. The government test results showed this siren with its two-stage blower was capable of producing a sound output of 134 decibels at a frequency of 430 Hz at a distance of 100 feet.

One of the problems with the early sirens is that the sound they produced was directional. To solve that problem the sirens were fitted onto a belt driven turntable that would rotate a full 360 degrees at 1.5 revolutions a minute. An operator was required to sit on a tractor type seat and control the operation of the siren and the direction of rotation, a job for which I am sure their were not many volunteers.

The second design of this siren built by Chrysler was much more refined than the first. Improvements in design also made the assembly of the sirens easier, faster, and less expensive. In the second design, the Bell name was dropped, and the sirens simply became known as the Chrysler Air Raid Siren.

The second design used the same 140 HP engine as the first design and the sound output was said to be the same. The second series was built from the middle 1940's up through 1951.

In 1952, a final and more advanced model was introduced. Along with a few refinements was the addition of Chrysler's new 331 cubic-inch, Hemi-Head V8, which produced 180 HP at 4600 rpms.

The latest design proved to be the best ever. It was by far the loudest at 138 decibels at a distance of one hundred feet at a range of 460 Hz. Best of all it was controlled remotely so no operator was needed to ride the siren and run the controls.

To put this Hemi powered air raid siren's output loudness into perspective the telephone in your shop rings at 80db while a city police car or ambulance measures120db at a distance of ten feet. Now imagine 138db at a distance of 100 feet… Yeeoooow!!

 This design became the most popular and a couple of hundred were sold to larger cities across the United States. Besides their tour of duty for World War II, many of the sirens were again used during the cold war when the threat of nuclear war became very real in the 1960's.

While no examples of the first two siren designs are known to have survived, a few of the third design (which was built up through 1957) have survived.

The Siren Harry Barry bought and restored that was once located near the school where he grew up.

Harry Barry grew up in Pittsburgh Pa. area during the 1950's and he clearly remembered there was one of the third generation Chrysler sirens near his school. It was tested each month and Harry remembers that very loud distinctive sound.

In later years Harry became interested in sirens (no doubt influenced by his early childhood), and went back to see if the siren was still there next to his old school. It was and he bought it. He then went to work and restored it. He tracked down and bought one more, and knows the whereabouts of  (6), more.

So the next time you are attending a car show and see a 1957 Chrysler cruising by... you may want to take a moment, and reflect on what might have been. Instead of that Hemi engine rumbling under the hood of that Chrysler, it could have ended up in service to our country.

Like Harry I also have an interest in and collect sirens. I have about 3 dozen sirens in my collection of all different shapes and sizes, the oldest one being from about 1926.

I do not have a siren in my collection as big as the one Harry has bought and restored but I can appreciate his efforts to track down and restore one of that size. The largest one I have ever owned was the one that was on top of our City Hall building when I was growing up. It was an old air raid siren from World War II. After the war it was used by the fire department. When the local fire department got a fire alarm they would turn on that siren to let all of the volunteers know of the alarm and they were to report to the fire station immediately. You could literally hear that siren for miles around so everybody got the message, and they often said it would wake the dead.

Later... when modern technology came along all the fireman got hand help radios and pagers so they no longer used the old siren. When it came time to repair the city hall roof after a hail storm the city decided the old siren needed to go away. They took sealed bids and I was the winner.

Soon after I learned that it ran on 3 phase 5 hp electric motor.  I befriended one of the local city public utility workers and we tried it out on a Sunday afternoon.

The World War II Siren from City Hall all 280 pounds worth.  It is nearly five feet across and the rain cap on top looks like an army helmet from back in the day.

I knew the siren was loud on the top of city hall but when it was on the ground sitting on top of my car trailer in the alley... it gave new meaning to loud. After a couple of times,  I had my fun, and the neighbors had made it clear they were not impressed with my siren. I eventually sold it to a small community in Oklahoma who wanted to use it as a tornado siren, a job it was clearly up to. With a population of barely 800 residents they clearly did not have much of a budget for storm warning devices, although like Kansas, they clearly had the need for one.

So in the end... I had my fun, got my money back, and there is a small town in Oklahoma who can now warn their residents of an approaching tornado. I have stopped in that small town a couple of times over the years to look at my siren perched on top of their City Hall building. I just smile to myself... it is in a good place and my neighbors couldn't be more pleased.

And I am still on the lookout for sirens to add to my collection. I am a little more selective now and leave the full sized ones alone.