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What sound does a popoff valve make, etc.?

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  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Tuesday, August 19, 2014 9:22 AM

Air pumps - everything from single clicks to double kettle drum booms.  Depends on the type and on the mounting to the locomotive.  Also depends on the venting of the exhaust (they are run by steam).  On our models, especially those with sound files already provided for the type, it will almost always be a double thump.

Blow-down - a loud roar.  Not a loud hiss, but a loud roar.

Pop-off - Also called safeties...a loud whoosh or hiss, not like the blow-down.  It's higher pitched.  Comes from those two or three brass thingies near the steam dome atop the boiler.

Injectors  - are manipulated/actuated manually, so they come on and off audibly.  They sound like water running through a biiiiiig pipe, and when the crew member shuts off the injector, just as with old copper or lead pipes and an abrupt valve closing, you get the loud clunk sound. (at least, that's what most decoder sound files make them sound like.  I haven't heard a clunk on the steamers I have frequented, but maybe I just didn't notice.)   Most modern steamers, say from 1920 on or so, had feedwater pumps that ran continuously except when the loco was stationary and not needing throughput from the boiler (lots of water in and steam out during hard working, say on a grade or during high speed runs on level tracks).

  • Member since
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  • From: North Dakota
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Posted by BroadwayLion on Sunday, August 17, 2014 2:24 PM

"POP_OFFffffffffffffst.............

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
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Posted by erosebud on Saturday, August 16, 2014 8:07 AM

All of these responses have been most helpful, each with its own unique contribution.  I'm really getting somewhere now, thanks to you.

  • Member since
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  • From: Collinwood, Ohio, USA
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Posted by gmpullman on Friday, August 15, 2014 4:23 AM

Browse around the TCS WOW Sound videos and some of the sounds can be identified as the narrator describes them.

This might be helpful for you. http://www.tcsdcc.com/Customer_Content/Web_Tools/Videos/WOWSound.php

Take care, Ed

ps: I recommend JMRI even for tweaking non sound decoders. The roster functions and the ability to SAVE your decoder configurations in case you need to reload them is worth the slight learning curve.

  • Member since
    February 2005
  • From: Southwest US
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Posted by tomikawaTT on Thursday, August 14, 2014 10:43 AM

I'm going to chop up your post so that I can address it sound by sound.

erosebud

I confess that even though I'm a steam buff, I really don't understand what all of the available sounds are.  Sure, I can identify a dynamo whine when the headlight goes on,

Pyle national specified that the turbogenerator should spool up with no load.  It shouldn't spool up when the headlight comes on.  Also, the headlight is hardly the only load on locomotive electricals.

I think I can tell when the auger is moving coal from the tender,

Crunching sound, like eating peanuts.

or the water is going into it, but these others are kind of a mystery:

  air pump,

heavy heartbeat, just after brakes have been used.  Prolonged before initial start - have to pump up the brake line and all the reservoirs.

 blowdown valve,

Gurgling hiss, not too loud.  Used to clear crud out of the firebox mud ring.

 steam cock,

Cylinder drains.  'Whoosh' timed to exhaust, four times per driver turn (or six, for UP 9000 class.)  First four turns after start, might be longer if engineer isn't sure the cylinders are water-free.

 popoff valve,

AKA safety valve.  The loudest white noise your speaker can handle without distortion!  Only happens if steam production exceeds steam consumption, and should be avoided/squelched by injecting water into the boiler.  A properly fired locomotive could, and should, run all day without ever lifting the safeties.

 blower,

Soft hiss rather like a loud sigh.  Used to build up the fire before starting motion.

 water injectors.

Running water as heard from the other side of the bathroom water wall, followed by a splashing sound as a half-gallon or so runs out the drain and onto the ballast.

I can't tell which one(s) I'm hearing, so I don't know about adjusting their relative loudness or putting them into a macro.

Hopefully, my input will make your job a little easier.  The one thing you didn't list is the soft hiss of the inevitable minor steam leaks - even on a loco fresh from the backshop.

Is there a place online where I can see a list of these and by highlighting one hear a little audio file of a typical sound for that piece of equipment?

Can't help here.  My knowledge was accumulated observing the beasts in their natural habitat.

Or has someone, as I seen suggested elsewhere, put together a CV "package" file for a representative loco that can be just plugged into one's throttle?  Is it time for me to bite the bullet and start using the JMRI programs--will they make this easier?

As my previous descriptions might not have indicated, all of these things (except the air pump, which reacts automatically to train line pressure, and the pop valves) are directly controlled by the operating crew in the cab.  To really 'do 'em up right' you almost have to qualify as both engineer and fireman - and running that one locomotive is a full-time job.  Using the JMRI programs might make it possible for you to do the conductor's job, too.

Chuck (Modeling Central Japan in September, 1964 - with steam, diesels and catenary motors that all sound the same)

  • Member since
    October 2001
  • From: OH
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Posted by BRAKIE on Thursday, August 14, 2014 10:16 AM

Larry

Conductor.

Summerset Ry.


"Stay Alert, Don't get hurt  Safety First!"

  • Member since
    July 2009
  • 178 posts
What sound does a popoff valve make, etc.?
Posted by erosebud on Thursday, August 14, 2014 9:38 AM

Friends,

I've only just started to use DCC and decoders, and I'm having pretty good luck with the little manual packaged with the loco when I try to customize the sounds a bit.  But I confess that even though I'm a steam buff, I really don't understand what all of the available sounds are.  Sure, I can identify a dynamo whine when the headlight goes on, and I think I can tell when the auger is moving coal from the tender or the water is going into it, but these others are kind of a mystery:  air pump, blowdown valve, steam cock, popoff valve, blower, water injectors--I can't tell which one(s) I'm hearing, so I don't know about adjusting their relative loudness or putting them into a macro.

I can tweak all of these (and more) by changing CVs.  But without making me an engineer, can you tell me how to distinguish the sound of one of these appliances from another, and maybe say when one would expect to hear it (i.e., only at startup, only at certain speeds, only when not covered up by chuffs, and so on)?  Is there a place online where I can see a list of these and by highlighting one hear a little audio file of a typical sound for that piece of equipment?

Or has someone, as I seen suggested elsewhere, put together a CV "package" file for a representative loco that can be just plugged into one's throttle?  Is it time for me to bite the bullet and start using the JMRI programs--will they make this easier?

Thanks for the help.


Is there

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