# Why do gas fired locos howl



## HampshireCountyNarrowGage (Apr 4, 2012)

Hello,

In viewing the live steam locomotives on utube I have noticed that some locomotives gas burners howl and others don't. Even in the same group of locomotives. What causes the howling and how does one stop it or quite it down?


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## Pete Thornton (Jan 2, 2008)

I would suggest you google "site:mylargescale.com ruby burner issues". There are many, many threads on the topic of burner 'howl'. 

It tends to be smaller locos that exhibit the worst howl - if only because larger ones muffle it with a big boiler and a longer flue.


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## Dr Rivet (Jan 5, 2008)

Pete T 

I thought it was because they all wished they were COAL FIRED. 

I figured Brit had her Ruby converted so it could feel better about itself and not be "wailing in anguish" so much. 

Live and learn. Thanks for correcting my unfounded assumption.


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## Pete Thornton (Jan 2, 2008)

Thanks for correcting my unfounded assumption 
Excuse me? I wasn't commenting on WHY they howl - just that there is info about the topic!


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## Chris Scott (Jan 2, 2008)

Posted By HampshireCountyNarrowGage on 03 Mar 2013 10:44 AM 
Hello,

In viewing the live steam locomotives on utube I have noticed that some locomotives gas burners howl and others don't. Even in the same group of locomotives. What causes the howling and how does one stop it or quite it down?




The saga and etymology of gas burner howling explained:
Today, steam loco gas burner howling is one of the most distinct and well-studied vocalizations. The ancestors of domesticated steam engines gas burner howl as a form of long-distance communication, conveying a range of information. Because of the high pitch and the suspension of notes, the sounds of loco burner howls can carry as far as 6 miles in the forest and even 10 miles the treeless tundra.

Loco burner howls serve as GPS systems, sing-alongs and fire alarms all rolled into one. In fact, the purpose of loco gas burner howls isn't terribly different from the reasons humans raise their voices to the wind. In general, the primary reasons why loco burners howl are as a rally cry to meet up. A signal to let the other gas burner locos know of a particular loco’s location as well as a warning for locos. 

The frequency of gas burner howling increases during the evening and early dawn when steam locos hunt. Burner howls punctuate the air more often during the wintertime breeding season, when gas burner locos seek out mates. Since burner howls bear coding for a loco’s burner size and health with larger locos exhibiting deeper burner howls exercise their pipes to attract other gas fired locos.

Although we think of loco gas burners howling alone they frequently do so as a group. These chorus burner howls involve members howling in unison at multiple pitches. Together, the chorus may include up to 12 related harmonies. Group gas burner howling can protect smaller loco since the combination of harmonies tricks listeners into thinking there are more locos present. Or sometimes, gas burners howl just for the fun of it.


I found this interesting bit of history by searching the Live Steam Forum archive using the term, "burner howl."


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## Pete Thornton (Jan 2, 2008)

how does one stop it or quite it down? 
Is anyone going to answer the other part of the question ? Can't wait . . .


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## Chris Scott (Jan 2, 2008)

Posted By Pete Thornton on 03 Mar 2013 11:40 AM 
how does one stop it or quite it down? 
Is anyone going to answer the other part of the question ? Can't wait . . . 

Chester,
Don't get any of us wrong. We are just trying to expose you to the wealth and extensiveness of the information contained in the archive resources of the Live Steam Forum archives and MLS archives in general.









We want you to take full advantage of all of our contributions to MLS over these many years. Plus there are usually multiple solutions to most problems, issues and/or situations for you to review and pick the right one for your case, skill level, tools and/or sense of adventure.


A forum's localized search tool is located right side just above the first topic and total forum's topic's page count.


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## David Leech (Dec 9, 2008)

Posted By Pete Thornton on 03 Mar 2013 11:40 AM 
how does one stop it or quite it down? 
Is anyone going to answer the other part of the question ? Can't wait . . . 
Convert it to Alcohol or Coal????
I only had one gas loco, an Aster NYC Hudson, and it howled, how it howled!
I thought that it was to do with the boiler design, one 'burner' flue, going into three smaller flues half way down the boiler.
I converted it to alcohol by changing boilers.
Now hearing all the Accucraft gas howlers, I realise that the howl seems to be inherent with gas and air mixing and rushing down the flue.
Even when turned down so that it doesn't seem to be heard by the naked ear, if you watch a video, it is very apparent. 
There seem to be people who mess with the poker burners and can make them quieter, but I seem to always hear it a little. 
Now there are different types of gas burners, and I would imagine that the 'non poker' ones are probably quiet, but I am not familiar with them.
All the best,
David Leech, Delta, Canada


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## HampshireCountyNarrowGage (Apr 4, 2012)

Hi Chris, 

I really enjoyed your "The saga and etymology of gas burner howling explained". I found it to be extremely outrageous that the history could go back that far. Hmmmmmmmm wonders will never ceases to amaze me. 

Oh. and thanks for the info too. I found the one about the fixes that were used to correct the Ruby worth while. 

David, 

As much as I enjoy the aroma of coal smoke, For me I find it easier to control the pressure and fuel usage with the gas. I maybe wrong, I was once, but in the videos I have seen, the locomotives that were opening their pops more and longer were the coal and alcohol fired locomotives. 

Yes Chris I knew you guys were funnin' me.


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## Chris Scott (Jan 2, 2008)




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## Britstrains (Feb 24, 2008)

Posted By Dr Rivet on 03 Mar 2013 11:34 AM 
Pete T 

I figured Brit had her Ruby converted so it could feel better about itself and not be "wailing in anguish" so much. 








Dr. Rivet yes it feels much better about itself now haha!


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## Westport (Nov 28, 2009)

Chris B, I am sure as with many others, I enjoyed your explanation of why my engines howl...it is rather lonely here for the poor locos so far from their southern brothers... 
David, at the risk of re-igniting the burning issue of alcohol vs. gas, you may have forgotten the excitement causing smell of burning ties on track (or even clothes) as those of us less experienced, or in a hurry or that @###@ engine .....light our own track or others, even at large public steam ups, in the past. I have to replace a three foot section of my newly laid 0 guage track due to my own carelessness on how open the fuel tap was turned. With your care and attention to detail, I have never seen it happen to you in the years that I have known you, but I have seen it happen to others and with the cost of track nowadays, perhaps it is a factor as much as the noise of gas locos is to some. And with the invisible flame of alcohol, it does not make as exciting videos as overfed gas lightings! 
Myron


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## Chris Scott (Jan 2, 2008)

Posted By Westport on 04 Mar 2013 09:36 AM 
Chris B, I am sure as with many others, I enjoyed your explanation of why my engines howl


Myron 

Myron;
Chris S not Chris B. Chris B makes Summerlands Chuffers. I just make occasional noise.


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## Westport (Nov 28, 2009)

Sorry, Chris S, me head is a bit fuzzy with da flu...so did not read name carefully... 
Myron


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## Mik (Jan 2, 2008)

It's been a long time since I dropped out of Physics class, but I think the "howl" is a result of the high speed airflow through the air metering orifices... like blowing across the top of a soda bottle. 

Sometimes building a "radiant burner" tent out of stainless screen will quiet it... and even increase run times because you're sending less heat up the chimney.


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## Phippsburg Eric (Jan 10, 2008)

I have done some fiddling with my Rubys which can be big time howlers!!! I added a screen tent to the burner on several with good results. that made them quieter so that all that you hear is a soft roar. 

Then I replaced the fuel tank on My son's modified Ruby with the new tank from the kit that I built a coal fired engine from. I installed the new jet while I was at it. WOW! THAT WAS LOUD!!! ( I have to type loudly so you can hear what I am saying) It turned out that switching back to the old Jet made it very soft spoken as a little Ruby really should be. I guess there are a lot of variables that can be messed with with varying results.


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## Semper Vaporo (Jan 2, 2008)

I have read where the best solution is to disturb the air flow through the poker burner.

Putting a tent on the burner can do that. Or partially blocking the air intake holes can do it.

Get a short length of metal tubing (K&S brass) that has an inner diameter slightly LESS than the outer diameter of the burner at the air intake holes. Cut off a short ring at an angle, such that one side is about 1/2 inch wide and the other is about 1/4 inch. Then cut through the ring at an angle so that it can be expaned slightly to slip over the burner at the air intakes and yet grip it tightly. Slide this ring partially over the holes so they are not all the same size. This will produce an uneven air flow and that disturbance will effectly break up the resonance of the tube (and as a side-effect, possibly improve the air/fuel mixing as it travels down the burner tube).

It does seem a waste to have to buy a whole 12-inch length of brass tube just to get a 1/2-inch ring, so if you can't think of a good use for the other 11.5 inches, you can substitute any other metal ring that can be slipped over the airhole to partially block them... any of several styles of Hose Clamp could work, or a ring for crimping PEX water pipe might work. It does need to be metal so as to withstand the heat in the area, but just about anything will do.


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## Chris B (Oct 18, 2009)

Hi folks - I have just found this thread and see that I almost responded earlier - thanks Chris for correcting that ;-) 

From my experience, I have found that Accucraft jets can vary a lot. I have two locos with the same gas tank - one lasted 20 mins and was noisy (though not as noisy as Eric's) and the other 30 mins and was quiet. The noisy one's jet was probably twice the diameter of the quiet one's jet when viewed through a jeweller's loupe. I bought a new jet holder to take a precision Primus jet (No5 I seem to remember) and the problem was solved. 

I have used nichrome mesh on a number of burners to quieten them. I have never managed to achieve the radient tent, but just tightly wrapped round the burner works. 

I had a huge problem with whistling on my Cheddar ceramic burner, but after a number of experiments, found that I just had it turned up too much so that the flame lifts off the ceramic. It is almost silent when working properly. 

SV's air control ring is another trick I have used - reducing the air can stop the howl. If you can smell unburned gas though, it needs more air. 

Cheers 
Chris


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## Brooks (Jan 2, 2008)

A fix for the howl - the Spiral of Silence: 
1) Form a long "spring" of ss wire (say 0.032" dia) to fit your flue. The spring should have open spacing between coils (1/2"), and have about 1/4" smaller diameter than the flue dia. Make it about 1/2 inch shorter than the distance from the end of the poker to the smokebox. 
2) Wrap a long roll of steelwool around the spring coils, making a long, curled "snake". Trap the ends of the steel wool in pinches of the ss wire at either end of the spring. 
3) Insert into the flue, pushing it back against poker burner, then pulling forward a bit. 

The Spiral of Silence, along with wrapping the poker itself with ss mesh, will muffle the howl - my Accucraft 2cyl Shay went from intolerably Loud to nice & quiet: you could easily hear the action of the cylinders as the loco chugged past. This mod makes lighting the poker a little more difficult. You may have to play with the amount of steelwool, reducing the thickness of your "snake", or you may need to open up the spirals of the ss wire, or you may have to experiment with how much you open the gas valve. 

As an added benefit, you will trap more heat from the burner as the steelwool becomes red hot. This radiant heat will increase the efficiency of your burner, so you will be able to turn down the gas. 

Hope this helps (All explained, with photos, in the old, pre-crash mylargescale.com, but I believe my original thread was lost).


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## Charles (Jan 2, 2008)

Brooks

Great to have you posting on MLS...be a while be always welcome!


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## Phippsburg Eric (Jan 10, 2008)

I would have thought the steel wool would just burn...It will burn breifly when a flame is played across it. but the general idea sounds good! perhaps if you use stainless or some other metal "wool" it works fine?


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## Brooks (Jan 2, 2008)

The steel wool snake does not burn in my loco. Maybe because a) the steel wool is not directly exposed to flame. b) the combustion gasses are depleted of oxygen. The wool gets red hot, and over a steaming season becomes brittle. You will likely have to replace it every year. Stainless steel wool would work, and might last longer. 

The purpose of the spiral of silence device is to a) change the resonance characteristics of the flue, b) muffle any sound waves that are generated - think a fiberglass pac muffler on a muscle car. The purpose of the spiral is to provide an exit path for exhaust gasses; if allowed to build up they will snuff the fire at the poker. This is why you can't just stuff a plug of steelwool in the end of the flue. Also, the spiral shape of the snake provides a path for the flame to flash back from the smokebox to the poker when you light up. If there is too much steelwool in the snake, there is not enough flash back space to get reliable lighting from a match flaring in the smokebox. I never light from the stack, so don't know if it's possible to do so with the spiral of silence. 
--------------------
Hi Charles, yes long time no typing. We had to, reluctantly, pull up our RR track several years ago: the neighbors cows kept coming over and stepping on it. He overgrazes his land terribly; when the cows are starving and see the nice green grass on our place, they hop the barbed wire fence. It's quite a sight, and would be humorous, if not for the destruction they cause.

I was over here yesterday looking for a source of gas-fill-adapters for butane/propane canisters. A guy over on the steamboats forum on rcgroups.com was looking for one. I found a vendor and he's placed an order...mylargescale live steam forum produces results .


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