OvermodAdding water vapor to cold compressed air will NOT give you any benefit.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Measurements indicate that only about 7% of the vibrating column in a typical steam whistle is actually steam. Very complex flow effects around the labra (in chime whistles) including phase change account for the timbre and quilling differences. Adding water vapor to cold compressed air will NOT give you any benefit.
As locomotives went to using superheated turret steam for auxiliaries, whistle performance suffered. I think there was only one long-bell Nathan design that was actually engineered and tuned to sound on superheated steam.
For true amusement and calliope like sound 'quality' investigate what happened on the N&W TE-1 when blowing the whistle with 600psi nominal. Even Big Jim would be hard pressed to excuse that stuff...
cx500 Back-up whistles on cabooses also used air pressure.
The pressure available from a locomotive steam boiler is considerably higher than most compressed air sources, and the flow can be sustained. A friend once tried blowing a 14L (crossing) signal at a traction engine rally. They have much smaller boilers than most locomotives. By the last long note the boiler pressure had dropped enough the sound was fading, so he cut it short. That was with steam, which is expansive. Compressed air is not, so you would need a huge air tank at an abnormally high pressure, or an immensely powerful compressor to match the performance.
The air whistles on interurbans and by some railroads for their diesels did not need the same volume and pressure. Back-up whistles on cabooses also used air pressure.
[quote user="tree68"]
Firelock76 No suprise there. Compressed air's better than nothing, but it has been said to get the best out of a steam whistle you really need steam.
No suprise there. Compressed air's better than nothing, but it has been said to get the best out of a steam whistle you really need steam.
Makes one wonder if introducing a bit of mist in the air stream would make a difference. Wouldn't be hard to do.
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Maybe, or possibly it's a "magic" combination of pressure, heat, moisture, and velocity through the whistle that makes a whistle powered by steam much more effective than one powered by air alone.
Possibly an expert in steam whistle sonics can explain it to us, if there's one out there.
I was partially inspired to pursue this project by listening to locomotive diesel horns echoing off the hills here in my neighborhood. I am fortunate to live on the UP main line (BNSF and Amtrak's Coast Starlight have trackage rights also), so there are many opportunities. I have learned that the UP has used the Nathan 5 Chime-type whistle on the 3985 Challenger in the past, which is cool as well. This is cow country, and my neighbors raise Angus, who seem fascinated by the whistle sounds. When I take this whistle to town, I have to be discreet. Last year I was given the opportunity to hook it up to a steam tractor at the local logging equipment museum, and at only 60psi it really rocks (compressed air pales by comparison).
everyone needs a hobby.
Very cool, and I do love the echo!
Firelock76,
With no small amount of digging, I was able to find a manufacturer of steam locomotive whistles. Below are some links to my Nathan 5 Chime in action - the first video is @ 150psi (60 gallon stationary compressor) recorded on my laptop (I really like the echo), and the other is @ 100psi in my mobile rig with a digital camera. These recording devices were not designed for this application, as is apparent.
https://www.youtube.com/watch?v=bv8DuFoSW3I
https://www.youtube.com/watch?v=iPbQPIyPVMA
I haven't posted here for some time - I hope this works.
Piker. He's only got one horn.
Check these out: http://www.dieselairhorns.com/trucks.html We still wonder where the four horns that were stolen from our locomotives in Utica ended up... Truckers do put them on their rigs, and I've seen videos of a couple of fire trucks so equipped.
We still wonder where the four horns that were stolen from our locomotives in Utica ended up...
Truckers do put them on their rigs, and I've seen videos of a couple of fire trucks so equipped.
Cool! He's probably got people wondering if there's ghost trains out there in the wilderness.
Actually, he's lucky he's got a place to "exercise" those diesel horns, 'cause strictly speaking, they ain't street legal.
Now if he could just get a steam whistle and hook it to a big ol' air compressor he'd really have people wondering about ghost trains!
Ha-ha-ha, most people move out West for the peace and quiet the wilderness brings but then.....
https://www.youtube.com/watch?v=5mfun9t31cE
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