Wanted: Air-powered engine sound module

As this photo of the Port Rowan turntable shows, the bridge is equipped with an air-powered engine to turn it:
CNR 86 on the Port Rowan Turntable photo CNR86-TT_zps01eb4c0d.jpg

I’m a big fan of sound on a layout – both for the trains and for the scenes through which they pass. I intend to add scenic sounds as appropriate – from birds to streams. One of the sounds I’d like to include is that of this air-powered engine at work. Therefore, I’m looking for an appropriate sound module.

I would like to set up this module so it runs only when I throw the switch to operate the turntable. (This switch is a SPDT style – as one option, I could replace it with a DPDT and use the second set of contacts to control the sound module.)

I have yet to find an appropriate module. Miller Models is no longer in business, and a search through the catalogues at Ram Track and Innovative Train Technology turned up some lovely sounds… but, alas, nothing suitable for this application.

So, I’m throwing the question out to you, the readers: If you know of one, use the Comments function to let me know. Thanks in advance!

8 thoughts on “Wanted: Air-powered engine sound module

  1. Trevor,

    Check out this video of D&S using their steam driven turntable.

    You can hear the turntable motor, but the K-28 just about drowns out the noise of the table at first. If you listen further though you can hear the noise the table makes as they try to spin it in the snow. Listening to it,I think any machine shop noise would do. That said, can you use your milling machine and record the noise it makes as it is running? Sounds like you would be drilling something if you close your eyes.


  2. UPDATE: I just found this YouTube video of a restored air-powered turntable motor – and it’s located at my closest railway museum no less!

    It’s a larger motor than the one I’ve modelled but gives me a good idea of the sound I want to capture.

  3. Dear Trevor,
    As far as a sound module which would give the sonic performance to do your visual model justice, I would strongly suggest checking out the DreamPlayer range by Pricom Designs. (http://www.pricom.com) For the turntable “one shot gag”, I would reccomend the LITE as a single-file triggerable CD-spec player. (http://www.pricom.com/Trains/DreamPlayerLITE.shtml).

    In terms of actually getting a sound _file_ for the hardware to play, that Youtube is possibly a good place to start. Another alternative would be the FreeSound Project (http://www.freesound.org), or if you’re _really_ keen, you could _scratchbuild_ the required sound.

    Above all, NB that you’ve just run up against the #1 reason for bad, unforfilling layout sound. There are plenty of hardware players, particularly in the cheapo end of the domestic audio market, which can be used to provide easily do-able “Layout Sound” support for most any layout and budget. Equally, there are some modellers who are working very very hard to make various forms of programmable PC-based players which seek to “compose entire layout soundtracks”(sic) from pre-programmed scripts, scale-time triggers, and “effects lists”.

    All of this is very impressive from a “clever technical” perspective, but without a _suitable_sound_ to play, all that audio gear is just silent sonic paperweight.

    Given this need to “trust their ears” and actually “model” the sound that their mind’s-ear tells them the “scale noisemaker” should be making, (and facing the fear that such a modelling project instils), many modellers look for the “easy way out” via “preloaded” sound modules. Now, don’t get me wrong, nothing wrong with pre-programmed sound modules, but with such modules being invariably ISD (digital vocal notetaker) based, with severely limited audio performance and recording time, we get a “perfect storm” situation where:
    – the modeller accepts a sound which is _not_ what their ears tell them their carefully crafted visual model _should_ sound like
    – extruded thru what is admitedly _ugly_ digital audio compression and “built to a price, not to a spec” playback hardware,

    and comes away with shattered expectations, a degraded model presentation, and a very poor perception of “the value of adding sound”.

    And you know the really sad thing? Our ears never stop listening. We _know_ what any given “noisemaker” should sound like, instinctively, without even trying! (Quick experiment. Close your eyes, and think about a clock. Now, without any more info from me, I _bet_ you could tell me _exactly_ what that clock _should_ sound like, and if I played you a sound of a clock, you could tell me, with absolute conviction, whether my example was or was not “the clock you had in your mind’s eye/ear”).

    One does not need to know any level of audio technical jargon to _know_ when the sound you are hearing is “right” compared to what your “mind’s ear” _tells_ you it (the noisemaker in question) _should_ sound like. But sure as eggs, if it sounds _wrong_ (wrong sound, compressed, distorted, lo-fi, whatever), you brain will _know_ that to, and simply will not let you accept that it “sounds right”…

    We’re getting off the track a bit, but suffice to say:
    – choose player hardware that is actually able of transparently reproducing whatever the sound is you require, and preferrably allows user-loading
    – Trust your ears, if a pre-loaded sounds wrong, it’s wrong, and your brain will not let you forget it
    – There’s plenty of license-free audio “source fodder” out there from which one can kitbash most any sound their ears tell them “sounds right”
    – and with free audio editing tools such as Audacity, if one can post a Model RR forum post, one has the PC literacy required to edit up one’s own “perfectly tailored to _your_ requirements, because it’s _your_ ears that were right there to tell you it sounded right” layout sound files…

    I hope this helps,

    Happy Modelling,
    Aim to Improve,
    Prof Klyzlr

    • Hi Professor:

      As always, a very informative contribution on the subject – have you considered blogging? 😉

      Thank you for the feedback. You’re right of course – many hobbyists do not invest the thought or the money required to do good layout sound. And all the gear in the world is pointless if the required sound – or suitable source files to manufacture the required sound – is not available.

      In snooping about YouTube, I actually did find a second video of the air motor from the Toronto roundhouse. As you note, perception is often more important than reality and it sounds almost too busy for my liking.

      The model engine in this video – while a four-stroke – sounds more like what I think the air motor on my turntable should sound like. Given that I’m looking for low sound volume I may be able to use some sound out of this. I’ll need to experiment with capturing sound off YouTube…


  4. Hi Trevor,

    Came across this little gem – the slow, cautious approach is something to remind your crews about when turning the loco, too – and remembered this thread. Enjoy!

    • Good point, Simon – and we do take it slow on and off the turntable.

      I encourage crews to stop before the turntable, to let a brakeman check the alignment of the approach rails, monitor the engine’s progress as it rolls onto the table, give the stop signal when the locomotive is balanced, etc.

      Then there’s a pause before and after turning, to connect/disconnect the air line from locomotive to turntable air motor.


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