What type of siren is this?

[AllAmericanFE]

http://www.jmarcoz.com/stationalerts/repairs.htm

http://www.jmarcoz.com/stationalerts/mon10.jpg

http://www.jmarcoz.com/stationalerts/mon.wav

[SirenMadness]

That thing is a beast!! The chopper is not as efficient as one with a ring on the intake, but it certainly looks pretty! The siren surely looks like something from Federal Signal, as the assembly inside the housing is rather relevant, though I'm not sure of Federal Signal making or using such chopper. That siren REALLY has a nice sound to it!

[pyramid head]

Well to me, that looks like a Banshee with a custom or modified housing. I being very new to this stuff, could be in all ways wrong about that! The housing does look like it would be factory standard, but something does not look right.

[Daniel]

It looks like one of those WWII Decots that was sent to Seattle, and has the same port ratio.

[PhRed]

Firstly, I don't think Banshees take that major interval tone-wise. Secondly, I don't honestly believe that an old fashioned Decot could handle a motor that makes this baby wind up as firecely as this(IIRC BTW most Decots I've heard online have quite slower wind-ups.).
Therefore, my vote is:
A 40V2T on a 1-phase motor and customized housing.

This is all just my opinion free to be summarily debunked.

[Daniel]

Debunking in progress . . .

The 40V2T is a relatively new siren, with a pitch interval modeled on the Decot, if I'm not mistaken. It has two separate rotors, both of which are considerably larger and taller than this one. Also, it has a much slower windup of about 10 seconds. Federal Signal never made a 5th interval siren to my knowledge, and neither did Sentry's predecessor Sterling. The siren in these photos is quite old, and has the same kind of motor mount as the 6/10 Decot being restored by another member. During the war, Seattle purchased several 10/15 Decot sirens which had Model 5-style housings instead of the more familiar Decot "laundry basket." The motor in this siren is a typical 1920's-1940's design, and unless Hedberg (which also used housings like this) had dual-toned sirens, this is almost certainly a Decot.

[PhRed]

Thank you. Come to think of it, this one does have a C-sharp tone that I've heard on another Decot recording. I Think it's from Madison, WI????

Anyway, this is indeed a jewel of a find and congratulations are due to the one(s) who put forth this labor of love.

PS: Can Sentry do anything to aaddress that IMO shameful windup issue? By the time it gets to full cycle, the fire will have done its work, alas.

[Daniel]

I wonder if Sentry sirens have a break-in period where the tolerances become looser after a few months of operation. The 10V sirens I've heard in person rise and fall at a normal rate, but on Sentry's factory test videos, both are much slower. The wind-down rate is controlled by rotor weight, generated wind resistance, bearing condition, and resistance from the inactive motor. The speed of the windup depends on these things plus the horsepower of the motor. The 40V2T has two heavy rotors and a 40 Hp. motor. If one installed a 50 Hp. motor, it would wind up faster, but the sound output would be the same. Like the old Sterlings, Sentry sirens have longer rotors than other sirens (long rectangular ports), so with the extra metal and longer "fan blades," they will accelerate and decelerate slower than a siren with a shorter rotor (squarer ports) like this Decot-like one. Actually, I rather like the 40V2T rise/fall rate.

[AllSafe]

40V2Ts are monsters. They are twice the diameter of a 2T22, taller than a Cyclone, and almost the same weight as a T-135. A couple of people could easily tip a 2T22 over on its side without its horns, but the 40V2T weighs in at almost a ton, and it has to be moved with a crane.