The airraidsirens.com FAQ
Answers to the questions I get asked by email all the time
1. Where can I buy a hand crank siren?
One good place to look is eBay. The most common kind for sale is the Federal Signal Model G, which is a small (5" across) high-pitched siren designed during WWI as a gas alarm, not a proper "air raid" siren. These sirens are on ebay usually several times per month, and the selling prices range from $200 to $400 depending on condition. WWII-vintage models with carrying case generally get the highest bids.
If you are looking for a larger siren, eBay is not a good option unless you are extremely patient and have a lot of disposable income. If you're interested in purchasing a new-in-the-box Klaxon Signals large hand-crank siren, email for details. They are $1320 from Edwards Signals.
2. What is the loudest air raid siren ever made?
It is the 180HP V8-Hemi engine powered Chrysler Air Raid Siren, 138 dB @ 100 feet.
3. What is the loudest air raid siren currently made?
It is the American Signal T-135, a 50HP uni-directional siren capable of 135 dB @ 100 feet.
4. Where can I get my own electric air raid siren?
I have three suggestions. The first two are for collectors/enthusiasts, and the last is for those of you looking for an affordable used siren for installation in active fire or tornado warning service.
Ebay is one place to look, but these sirens do not show up that often, perhaps there are a handful each year. The Federal Model 2 and 2T show up most often, and generally sell from $400 to $750 depending on condition an what is included (housing, timer, starter, etc...). Larger sirens are usually much cheaper because nobody can afford to move them so they get only local interest. You can usually score a 3 to 10 horsepower siren for $100-$300, but you need to be able to go get it because they're all at least 300 pounds.
The next best place to go are local fire stations, to see if they have an old siren that is not used and can be sold. If you live in an area with active sirens, you can call the siren manufacturers to see who is responsible for siren installs and maintainence in your area. These contractors often have removed-from-service units laying around.
Next you can try siren resellers like West Shore Fire, Braniff and Nelcom. You will pay a bit more than scrap prices, but you will get a siren that has been checked over and in good shape for service. If you're looking for a unit to be put back into active storm warning service, these are really the only outlets you should consider. I recommend ebay and scrapyard sirens only to enthusiasts and collectors, not towns than need to rely on the sirens to save lives.
5. Can I run an air raid siren from household power?
You can run single-phase 120V series-motor sirens and 208-240V series or repulsion-induction sirens from the power that comes into your home. Anything up to about 7.5 HP will run well provided you run the appropriate heavy-gauge wire to them directly from your main panel. Sirens larger than a 208-240V Model 2 will require a motor starter relay of the appropriate size.
You cannot run 3-phase sirens from home power without some expensive and heavy conversion hardware. With appropriate conversion, 10HP is about the upper limit for 200A home service. Large capacitor-start sirens are also a difficult load to run from home power, due to the large inrush current requirements.
6. Is it legal to run an air raid siren at home?
Short answer: no.
Long answer: It depends a lot on where you live as to what you can get away with. In most states you will at least be violating a noise ordinance, unless you have a large enough plot that your siren is down to 70dB by the time it reaches the edge of your property line. In areas with active sirens for tornados, nuclear plants, etc. it is a serious crime to create a false alarm using a siren. In some states, it is explicitly illegal for anyone to operate a dual-tone siren, and in other states it is illegal to set off a civil defense alarm except during a designated and limited testing period.
In areas with active sirens, the laws are strictly enforced. In areas without sirens, the occasional blast will likely go unnoticed.
7. What is required for hearing protection when operating these sirens?
I use Peltor H10A earmuffs. These are adequate protection (NRR 30dB) for all but a full-powered Thunderbolt, T-135, or Chrysler siren at close range. For the biggest of the big, you need foam earplugs plus the earmuffs.