Steam whistle-pitch pipes

[michael howarth 1Participant @michaelhowarth1]

Whilst tootling around in the workshop I came across a pitch pipe-brass chromed tubes, just over an inch long and joined together like pan pipes. They make quite delightful sounds which would sound really good on a loco as a whistle. Whilst they work perfectly when gently blown into they refuse to emit any sound when blown into with compressed air. Does anyone with knowledge of these pipes know what needs to be done to convert them into a steam whistle?

[michael howarth 1Participant @michaelhowarth1]

[duncan webster 1Participant @duncanwebster1]

Problem is the different speed of sound in air and steam. I wish you luck, but I'm not holding my breath.

[noel shelleyParticipant @noelshelley55608]

I'm pretty sure this matter has been discussed in ME at least once, but a few years ago ! Noel.

[Nigel Graham 2Participant @nigelgraham2]

The clue might be in the question itself: not only the speed of sound (which depends on the density of the medium, not its pressure as such) but the pressure of the air or steam entering the whistle.

Over-blow a recorder, say, and it emits a harsh squeak at best, and that's just by lung effort.

[Roderick JenkinsParticipant @roderickjenkins93242]

Mick,

Your pitch pipes are probably for tuning violins (4 pipes) or guitar (6). If so, they will likely be reed pipes rather than a flue pipe as used for steam whistles.

Rod

[michael howarth 1Participant @michaelhowarth1]

Hallo Roderick. Yes they are reed pipes I believe. Does that mean that they will not work with steam?

Nigel. Overblowing the pipe does emit a strangulated squeak of sorts just as in your recorder analogy. The strange thing is that I barely have to breath into the pipe to get a fine mellow note but they will not work on compressed air however low the pressure.

Mick

[Michael GilliganParticipant @michaelgilligan61133]

Mick

Diagnosis at a distance is difficult [!]

But I suspect that your “however low the pressure” is still way too high

The maximum pressure that your lungs can blow might be around 2psig, so your gentle breath would be a tiny fraction of that.

Experiments with a manometer tube might be helpful

MichaelG.

.

Edit: __ I have just found a wondrous list on Wikipedia:

 https://en.wikipedia.org/wiki/Orders_of_magnitude_(pressure)

[ Wondrous if you like that sort of thing ]

Edited By Michael Gilligan on 20/10/2022 09:01:53

[Author]

Posts