Sentry Rotating Siren

[500AT]

While digging through my file cabinet, I found a letter from William E. Yarberry, Sentry's Sales Manager, dated February 12, 1990. In this letter, Mr. Yarberry describes their new 135 dB rotating siren:

"If you are interested in the largest siren possible, we can supply a 135 dB rotating siren that has recently been developed and patented. This siren would be powered by a 100 HP air compressor and give you unbelievable distances. This type of siren would be considerably more expensive than our normal sirens but it does give the additional distance."

My question is, what siren was this? Was this a sole venture by Sentry, or were they in partnership with another company?

[pyramid head]

That would be a beast. I have never heard of a 100 HP motor...

[Conky 2000]

I would guess that Sentry somehow made a joint venture with ACA/ASC to produce the T-135, but the deal was broken. If you have an address, you should mail them back and ask them. Perhaps, as in the case of the EOWS* 612, it could still be made but not featured.

[JasonC]

I would guess that Sentry somehow made a joint venture with ACA/ASC to produce the T-135, but the deal was broken. If you have an address, you should mail them back and ask them. Perhaps, as in the case of the EOWS* 612, it could still be made but not featured.

That makes absolutely no sense. The T-135 is not run off of a 100hp air compressor. Lets be a bit more realistic here.

Ron, try e-mailing Bill or Scott, I'm sure they will be more than happy to tell you about that siren.

[Rory Buszka]

And, please give us all the details you can. See if they can send any drawings that depict a general view of the siren. 100HP seems a bit excessive in my estimation, however, since a 30HP motor should be plenty for a regenerative blower to power a siren developing 135dB. I wonder if they used a well-designed exponential horn (like on the Hurricane and Thunderbolt) to convert the high-volume input to high pressure at the mouth of the horn. That's the only way the 'blown' siren concept really works. The horn length also needs to be 1/4 wavelength of the lowest frequency that it is desired to amplify. The low cutoff of the Hurricane MkII horn was in the neighborhood of 80 Hz.

[Jim Z]

I have never heard of a 100 HP motor...

we have a hydraulic vibration table where I work which is driven by a 125 hp electric motor. It's 600VAC, three phase, and about 2300 lbs.

[500AT]

Ron, try e-mailing Bill or Scott, I'm sure they will be more than happy to tell you about that siren.

Done, now I am waiting for a reply.

[500AT]

Here is the reply that I received from Scott Yarberry:

I know what you're speaking of, but this unit was never mass produced due to it's high cost. I don't have any literature, drawings, etc on this product, just some vague memories from some of the older engineers. Sorry,

Scott Yarberry
National Sales Manager
Sentry Siren, Inc.
Office: 719-275-8691 - Ext. 114
Fax: 719-269-3397

[pyramid head]

That is not really a suprise. Though they were not mass produced, do you think one or two of them were made?

[Gil]

I figured that was the case, seeing as no one around here knew about them until now.