The Steamboating Forum

I am trying to make a whistle snubber that reduces the dB so it doesn't scare people.

I made a 3/8" NPT Coupler like this: Is there a relative relationship between A and volume in dB assuming the same steam pressure??

I made A a little less then 1/8" and it's still a bit louder then I like.

I drew B in the drawing but I assume as long as it's long enough and doesn't create a nozzel it shouldn't matter much.

-CB

There's really no way of figuring this sort of thing w/o characterizing the sound output of the whistle; I'd be inclined to use a small needle valve to adjust things. Be prepared to fiddle when the boiler pressure changes.
Perhaps a better approach is to use a really small whistle valve; that way you can control how much noise the whole thing makes...

- Bart

I have a valve to quiet my whistle down but, as Bart says, the setting has to be changed as the pressure changes. I have a notion that the relationship between sound output and steam pressure might be non-linear. Like twice the pressure yields more than twice the noise.

I suppose a regulator of some sort would do the trick.

The volume of a whistle is related to the length of the flute.

I.e. a whistle with a flute 360 Degrees round would in theory be twice as loud as a whistle with the flute only on the front half.

I'm not sure how I would come up with a scheme to vary the length of the flutes as the pressure changes.

Now that I think more about my wonderful regulator idea I see a major drawback. One more lump of metal to warm up before the whistle stops showering me with scalding water. Oh, well

Lopez Mike wrote:I'm not sure how I would come up with a scheme to vary the length of the flutes as the pressure changes.

Piece-wise approximation: use several identical whistles and bring more on-line.

Put the whistle valve up at the whistle to help w/ the shower problem.... any condensate will flow back down into the boiler.

- Bart

Lovely. I'm already under the stink eye for too much tootling and you want me to build a Calliope? Right.

And it would be sure to be badly out of tune.

Mike.
Take a look on page 15 November/December 1962 "Steamboats and Modern Steam Launches". There's an example of what amounts to a slide whistle. You might even be able to play Yankey Doodle on it?

Dave

You guys are hell bent on making me into a bachelor steamer.