# What makes a choo-choo go "choo choo?"



## joe rusz (Jan 3, 2008)

Four times a day, when the wind is right, I can hear the Sugar Cane Train pass by on its way to or from Lahaina, Maui. It goes like this: "CHOO, CHOO, CHOO, choo, CHOO, CHOO, CHOO, choo." Notice the stongest empahsis is on the first three beats. Now if you go to the Phoenix Sound wensite and listen to their sound samples, every one of their steam locos, despite their different whistles, sound the same. Namely: "CHOO, CHOO, CHOO, CHOO" etc. It's kind of redundant and sounds like they just looped the same sound, which could very well be electronically generated, and thus, not authentic.

So what's the deal? And why don't they (as that comedian on Saturday Night Life says) "FIX IT!" ?? I have two older model Phoenix sound systems and while I like them, I would think that in this day and age we could get a sound system that really replicates the real thing.

TOC, knowing how much you _*love* _sound systems, ignore this post and go work on you Jag-u-was.


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## Bill Swindell (Jan 2, 2008)

I've fired and run real steamers and am not sure I've ever heard the occasional weak choo. The only change that I have noticed is what happens when the throttle and Johnson bar are adjusted.


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## Greg Elmassian (Jan 3, 2008)

*RE: What makes a choo-choo go "choo choo?"*

I've heard what you are saying Joe, but I think my brain is stuck in 4-4 time and it's searching for the "Repeat"... I would swear one of the chuffs was distinctive, but then if I force myself to "Sync" on another, I finally convinced myself I was just "hearing things"... It's probably the early stages of dementia. 

Regards, Greg


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## East Broad Top (Dec 29, 2007)

*RE: What makes a choo-choo go "choo choo?"*

The irregularities in the volume of the chuff is due to the valve timing being a bit less than ideal. On a perfectly timed locomotive, all four valve events would have equal emphasis (volume) as the amount of steam passing through the cylinders during each cycle would be the same. If that is off, then the amount of steam passing through the cylinders is unequal, and the resulting chuff would vary in volume. This could be due to a few things. First, the position of the Johnson bar affects the position of the valves. What's even at one position may not be at another. That's why sometimes you'll hear locos running evenly in one direction, but a bit off when reversed. Also, the valve timing could simply have slipped. The valves are typically held in position by nuts and bolts, which might slip over time depending on the assembly. It could also be caused by slop in the valve gear. If the bushings aren't tight, then slop might delay the valve events a bit one way or the other. Valve timing--even in the height of steam operations--was somewhat of a black art, and one skilled in timing valves was a truly valued shop employee. 

Later, 

K


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## Mik (Jan 2, 2008)

*RE: What makes a choo-choo go "choo choo?"*

My traction engine is a 2 cylinder just like a locomotive. The valve linkages on the right hand cylinder are badly worn due to a previous owner's spotty lubrication practice (beyond what I was able to take up by removing the shims), so the engine is slightly "lame" on that side. The result? One wit listening to it run under load started saying "Good 'n Plenty,Good 'n Plenty,Good 'n Plenty,Good 'n Plenty" along with it.... /DesktopModules/NTForums/themes/mls/emoticons/sad.gif 

Sounds like the loco you are talking about was out of square as well. It needn't even be a misadjustment, or wear. When they rebuilt the 15" gauge Crown locomotive that's at Rough & Tumble, they found that part of the reason it sounded lame was that the cores had shifted when one cylinder was originally cast, resulting in irregularly shape ports. I was told it took quite a bit of work with a die grinder to get them close to spec, and the rebuilt loco sounds MUCH better, but you can still hear it's off just a tiny bit


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## SlateCreek (Jan 2, 2008)

*RE: What makes a choo-choo go "choo choo?"*

If you're using magnets to time the chuff on your model engine, you can put one of them off square and make the sound system do the same thing.... on a Phoenix, if you turn the "chuff smoothing" all the way down (otherwise it'll try and force an even beat) and the "chuff randomization" up, with an "unsquare" magnet arrangement you'll get a locomotive that sounds horribly out of time. This will also get you around the Phoenix classic CHUFF CHUFF chuff chuff CHUFF CHUFF chuff chuff that you often get at about the midpoint of it swapping from heavy to light chuff. 

In 1:1, Valley RR #40 was originally deliverered with the valves timed deliberately to give an advantage in forward, since the locomotive never really ran in reverse. The result was, at the VRR where half the trip is in reverse, you'd get a "chuff chuff **CHUFF!!*** .......... chuff chuff ***CHUFF!!***" pattern in reverse. It took a couple of really good guys a couple of days to reset all the shims and wedges to line the gear up so it was more even.... and the engine quit waltzing in reverse! 

Valve timing is wierd. I have a clip of Georgetown Loop #40 running at the CRM .... and I swear the pattern is "Chuff Chuff Chuf-a-chuff Chuff Chuff Chuff-a-chuff." I have no idea how you'd get that... but it does give each engine a unique voice even beyond the whistle. 

Matthew (OV)


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## Semper Vaporo (Jan 2, 2008)

To expound on what others have mentioned already.

Musically it is usually represented as one loud beat followed by 2 or 3 softer beats (should be 3 but some musicians take poetic license!) represented as 4:4 march time.

The sound comes from the release of steam from the cylinders after it has expanded to push the piston. The steam is directed up the "Blast pipe" in the smoke box to cause a flow of air up the chimney, which sucks air through the flue tubes in the boiler, drawing the fire from the firebox with it. The air in the firebox is replenished from below the firebox, which makes the fire burn hotter. The more steam going up the chimney the more the fire burns hotter... the steam locomotive is said to be self regulating that way. The sound emanates from both the steam chests and the blast pipe and resonates in the chimney. The majority of the sound is heard from the chimney.

There should be some variation in the loudness of the chuff for several reasons. Timing of the valve gear is some of it, and you may think one chuff is louder than the others because of a short lull between two chuffs due to a slightly later release of the exhaust on one end of one cylinder. 

Another cause is noticed by some people because the opposite ends of each cylinder are different volumes... the piston rod consumes some volume and thus there is slightly less steam released from the rear of the cylinder than from the front. Thus some people can hear an alternating chuff, such as: 'CHUFF CHUFF chuff chuff CHUFF CHUFF chuff chuff"; corresponding to: FRONT LEFT, FRONT RIGHT, rear left, rear right, FRONT LEFT, FRONT RIGHT, etc. Of course this assumes a 2 cylinder simple locomotive (i.e.: one that is not compounded) If there are more than 2 cylinders there will be more chuffs per revolution of the drivers and if the engine is compounded then there will be less. Something like the Challenger or BigBoy will have 8 chuffs but the two engines are never in sync so the chuffing gets very complicated.

The people on the engine seldom hear much variation in intensity because they are so close to it that the sound levels are pretty much at the top end of human endurance anyway, i.e.: they are all LOUD! 

To people a distance away there are other things that add to or detract from the sound levels that contribute to the perception of a loud and soft beat sequence; such as echos and obstructions between the source and listener.

I remember several years ago on a train forum where someone went into a VERY long dissertation as to the causes of the variation in levels of beat sounds and most of it is due to the perception of changes in loudness due to variations in timing between the individual chuff sounds.

Also, the sounds are louder when the engine is just starting because the engineer will have the longest cutoff set and that means more steam will be in the cylinder at a higher pressure. Once underway the engineer will move the valve gear to a shorter cutoff which allows less steam into the cylinder and it will have expanded the most and thus be at a lower pressure so all of the chuff sounds will be softer.


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## Chris France (Jan 3, 2008)

*RE: What makes a choo-choo go "choo choo?"*

Another thing that effects the volume of the exhaust beats would be the cylinder cocks. When starting and stopping the engineer will usually open the cylinder cocks to keep water from condensing in the cylinders. With the cylinder cocks open there is less steam exhausting up the stack and therefore less "chuffing." When I'm operating the William Mason I usually leave the cylinder cocks open only because we only have a mile of track and its easier to just leave them open for a distance that short. On that engine with the cylinder cocks open there is almost no noticable exhaust noise, but as soon as I close them it "talks" quite a bit.


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## joe rusz (Jan 3, 2008)

*RE: What makes a choo-choo go "choo choo?"*

Once again I am, impressed by the depth of information dispensed on MLS. You guys sure know your stuff! Anyway, thanks. One reason I brought this all up--and one of you addressed this--is that I find my sound system's chuff a bit redundant and am looking for a way to make the it sound more realistic. 

I was thinking of shooting some streaming (or is that "steaming?") video of Anaka (that's one of the two locos that's currently running on the LK&P) and putting it up on MLS. But, I need someone to tell me how to get it downloaded within the limited confines of our website. I'll be using my 8 meg Casio point-and-shoot. 

Also, I think I'll print out all of your comments and hand 'em to Anaka's engineer to see what he has to say, heh, heh, heh!


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## SlateCreek (Jan 2, 2008)

*RE: What makes a choo-choo go "choo choo?"*

Joe, 

If you've got the programming rig for the Phoenix, there's a lot you can do. 

First of all, always start off very slowly. Done right, you can get the cylinder cocks noise Chris describes above, and it will automatically shut off when you accelerate above a fast walk. If you can, turn off the blowdown .... it's not a pop valve as originally described (listening to it by itself you can hear the gate valve slamming...) and no locomotive blows down every time it stops like many of the default Phoenix sound sets do. Depending on what you use for control, you can set it up to be triggered when you want it. You'll still have the cyllinder blowdown on stop, automatically, and that (generally) works. 

For the road, if you set up chuff randomization high, turn the smoothing off, and make sure you set up a long transition from heavy to light, as you accelerate the pitch of the chuffing will shift up, and the volume will drop back a bit so that the engine doesn't sound like its working as hard. You can also play with the "johnson bar" effects so that things are more staccato as you speed up, but be careful; this is an added effect, and can detract from how "natural" it sounds if you overdo it. 

Decelerate slowly, and you'll notice that the sound backs down to a "drift" as you do ..... which is nice, as older systems would have the locomotive pound to a stop .... the only time I ever saw this done was at the 150th anniversary of the Kingston RI station, and that was with an Amtrak locomotive trying to hold #40 back .... long story. 

And, if you really want personality, and you're using magnetic chuff timers, move one magnet a little out of square .... but this may require heavily rusting and weathering the engine so it looks as badly taken care of as it sounds if you do it more than just the slightest bit! 

Mostly, remember that while 1:1 enginemen really try to go for consistent speed as much as possible, that conditions on a railroad change frequently, and it's not as consistent as anything in our model world can be. Grades and curves change load, and speed restrictions, station stops, and other "timetable" issues have you speeding up and slowing down a lot. Most of the time when your train gets "boring" it's because you've set the speed and let it run .... and after awhile it drones on. Change things frequently, and use a really light hand on the throttle and it'll sound a lot better. 

Matthew (OV)


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## joe rusz (Jan 3, 2008)

*RE: What makes a choo-choo go "choo choo?"*

Matthew, thanks for your comprehensive instructions, which I'll stash in my "Good Stuff" file for future use. Unfortunately, my Phoenix sound systems are several years old and predate the Y2K (or whatever they're called) system with its computer-programmable features--unless you know something I don't know, which is a distinct possibility. Some time ago, I sent one of my modules back to Ann Arbor where it was reprogrammed so that I could ring the bell and blow the whistle on demand--using my Aristo Craft module. But I can't control any other function, as far as I know. I would love to be able to actuate cyclinder blowdown and whatever else is lurking in there. 

BTW, no "choo-choo" today. It's been raining since midnight and they are running the critter, as I believe the steamer would get lots of wheel slip especially since the stretch from the first stop, Puu Kolii, to Kaanapali where we are, is slightly uphill. I've heard her slip on a sunny day, never mind a rainy one. One more thing, on the way back, on the downhill, she's drifting and all you can hear is the single-cylinder air pump, which is loud and goes, "Pow, pow, pow." Aren't trains fun?


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## Les (Feb 11, 2008)

Chris,

Excuse a possibly dumb question, but I'm not at all familiar with steam engines. Where are the cylinder cocks located, and how does the engineer control them from the cab? I never see anything like a cock in pictures or on models.

Les


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## Mik (Jan 2, 2008)

*RE: What makes a choo-choo go "choo choo?"*

If anybody made a sound system that sounded REAL (not just "close enough" for somebody who never spent a lot beside an engine working hard), then I might consider it. (just no way you can get that "feel" from a tiny speaker) Until then my sound system will continue to play Glenn Miller, The Dorseys, and Benny Goodman.......... 

My grandpa worked MOW for the B&O from the end of WWII into the late '70s, and that was his sound system of choice when he ran trains as well. Sometimes it makes me almost feel (wishful thinking?) he was still here.


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## Semper Vaporo (Jan 2, 2008)

Cylinder cocks are small valves on the bottom of each end of the power cylinders. The engineer has a handle, (often looks like a faucet handle on the side of your house for your garden hose). that has a long shaft with a couple of universal joints for going around corners, sometiimes the shaft doubles as the handrail along side the boiler (or is a shaft inside that pipe). The engineeer opens these valves when he thinks there may be liquid water in the cylinders usually after the engine has sat for a period of time without steam applied to the cylinders (station stops). Some cylinder cocks are automatic and have no manual control of them, they just open when water is present in the cylinder and close once the water has been expelled.


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## Mik (Jan 2, 2008)

Posted By Les on 01/27/2009 3:47 PM
Chris,

Excuse a possibly dumb question, but I'm not at all familiar with steam engines. Where are the cylinder cocks located, and how does the engineer control them from the cab? I never see anything like a cock in pictures or on models.

Les


The cocks are under the cylinders (water is heavier than steam) at each end, most models don't have them because they'd just get broken off...although some do have molded in "bumps" where they should be. Depends upon the era how they were activated. Early and smaller engines used reach rods, later they were run by steam or air pressure with a valve in the cab, and towards the end they were "automatic"


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## Semper Vaporo (Jan 2, 2008)

Here are a couple of lousy photos of the one of the automatic cylinder cocks on the Milwaukee Road 261:


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## Tom Lapointe (Jan 2, 2008)

"- I'm not at all familiar with steam engines. Where are the cylinder cocks located, and how does the engineer control them from the cab? I never see anything like a cock in pictures or on models."

*Les, I don't have any pictures handy at the moment, but the cylinder cocks are located (on conventional steam locos) at the bottom of the cylinders, 1 at each end. (They are not very obvious, unless you know specifically where to look *







- *on many models, just a small protrusion on the bottom of cylinders, just inboard of the cylinder heads). They are activated by a reach rod to a handle in the loco cab. Their function is to release any water that may have condensed from steam in the cylinders while the locomotive is standing; on full-scale locomotives, trying to start with (uncompressible!) water accumulated in the cylinders can blow the cylinder heads! *







*On simpler small-scale live steamers (such as my Accucraft Shays *







*& Ruby) they are often omitted; the forces generated are not high enough to cause damage *







*, & simply cycling the reverse lever (a.k.a. the "Johnson bar" *







*) back-&-forth will simply cause any accumulated water to be belched out the stack & smokebox drain. Some of the more elaborate (a.k.a. "expensive!" *














*) live steam models DO actually have functional cylinder cocks (I believe Accucraft's K-27 & Aster's Berkshire, if I'm correct) DO have them, typically operated by a small lever under the cylinders.*

*While the cylinder cocks THEMSELVES are not very obvious, their EFFECTS are! *







*If you watch a movie or video of a full-scale locomotive starting up from a full stop, you'll often see alternating puffs of steam emanating from each side under the cylinders- this is expelled water & steam emanating from the cylinder cocks. Hopefully someone will post a picture or video. *







*Tom*


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## Tom Lapointe (Jan 2, 2008)

*Thanks Mik & Charlie! (Both of you beat me on my reply!). *







*Tom*


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## Les (Feb 11, 2008)

And thanks to all THREE of you! I knew what they were for, but I've never seen any, even on the 'museum-quality' models. And I've definitely never seen a hand-operated rod shown in the cab of any model. I know this because when I learned of steam cocks some years ago, I kept an eye out when backhead pixes were shown. Then again, maybe I didn't know what I was looking at. (Nah, couldn't be that).







Was the rod actually a linkage arrangement that ended inside the cab in a handle?

I had no idea of their relative size to the cylinder, shape or metal type (brass or iron). Those great pixes took care of that.

Thanks to all of you for taking time to post.

Les


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## lownote (Jan 3, 2008)

That's very interesting--thank you all!


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## joe rusz (Jan 3, 2008)

*RE: What makes a choo-choo go "choo choo?"*

See how it is when we all play nice?


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## SlateCreek (Jan 2, 2008)

*RE: What makes a choo-choo go "choo choo?"*

The B'mann K-27 has some pretty well detailed cylinder cocks underneath. On 1:1 locomotives, I've seen both the hand / lever operated type and the air operated type. If you're watching a steam locomotive, particularly when it's first starting up, you'll see a blast of steam from underneath one end of the cylinder, just before it starts to move. As the piston reaches the other end of its travel, you'll see it stop, and switch to the other end of the cylinder (the ones on the opposite side will do this 1/2 a turn out of phase.) This blows condensation out of the cylinder, as everyone has already said, which is important because while steam will compress, water will not, and it's possible to have the engine "hydro lock" if there's water in the cylinder, and if it's moving at all, this has enough force to bend the main rod! (again, long story...) Generally the only time you see a lot of water from the cylinders is first thing in the morning; after that the engineman will use the cylinder cocks enough that not a whole lot builds up. Also, on most more modern engines, the locomotive is large enough that not all the exhaust will go out the cylinder cocks... there's still enough up the stack to have the locomotive chuffing and drafting on the fire, so you'll see all those things happening, though perhaps a bit diminished. As the locomotive moves forward, the steam will "dry out" and the engineman will close the cylinder cocks.... at this point the hissing of the steam stops, and the clouds stop appearing from the cylinders as all of it is now directed up the stack. 

The other feature is the "snifter" valves at the top of the cylinders, generally with some cooling fins. These drop open when the throttle is closed, and allow air to enter and exit the cyilinders, making it possible for the locomotive to roll without building up air pressure on the valves, or drawing a vacuum. When the locomotive rolls by you, in addition to the thumping of the pumps, you may hear a rattling noise (picture a thousand BB's in your dryer....) caused by the air rushing in and out. When the engineman opens the throttle, there's often a puff of steam followed by a metallic "CLACK!" as the snifters close.... at a station, when the throttle is closed, you'll hear them drop open with a clank, and you'll see puffs of steam at the top of the cylinders as any residual drifts out. 

Back on the Phoenix, if you have the Phoenix 97 (pre 2K2) you're pretty much sunk as far as tuning or triggering effects. There was some adjustment possible as far as timing was concerned, but it wasn't at all as flexible as the more modern versions. My comments about slow acceleration and deceleration will, however, help make the sounds that are automatically included work their best. 

One decided problem I have with the Phoenix auto-sounds is that the forward and reverse whistles don't actually sound until the engine moves.... unless you're set up for realtime whistle and are blowing it yourself. Sierra had a feature that allowed you to time it so the whistle would go before the engine moves.... as it should. 

Anyone who needs help with the Phoenix is more than welcome to contact me off board.... I have the programming rig, and I'll do my best to help set things up for you. 

Matthew (OV)


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## Les (Feb 11, 2008)

Thanks, Matt.

That's what I call a comprehensive answer.

Les


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## sschaer (Jan 2, 2008)

*RE: What makes a choo-choo go "choo choo?"*

the sugar cane train is a cute little railroad. had the pleasure to take a ride in 2006. 











pics here : http://www.sschaer.org/trains/lkprr/p1.html


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## joe rusz (Jan 3, 2008)

*RE: What makes a choo-choo go "choo choo?"*

Still running, but I worry about how long it will last. Toursim is way down and if it wasn't for the Japanese tourists (mostly) the train would be empty. Chuffin away today, though, even though it's cloudy, windy and trying to drizzle.


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