# Compressed air/Steam locomotive



## Kovacjr (Jan 2, 2008)

Here is the thread clip from where it all started.

Jason - How about one of those old compressed air locos. Always thought that would be interesting to make one and have a air tank on it. Need to fill up at least 120psi do decent run time if a few mins id guess depending on the cylinders. 

Henner - Jason,
we have thought about building such a compressed air loco. Unfortunately it seems almost impossible. 120PSi would give you probably just a couple of seconds of run time (120PSi expanded to say 12PSi = 10 times the volume of the boiler). Even 1200PSi would not cut it.
We also thought about dry ice (CO2), but here you run into two problems: Either the sublimation rate is too low or if the loco sits for a while, it creates dangerously high pressures. There have been attempts to sell dry ice powered locos, but they disappeared rapidly from the market...
Regards 

Jason - Henner what about using the cans from a paintball gun? Of course refilling is the issue then. 

Dan - 
Real fireless engines were charged with steam. Unlike compressed air, as it was used it would still expand. The exhaust was reused, I don't know how. Most of them were small 0-4-0's and would run a full 8 hour shift and have enough pressure to make it back to their "charging" station. Many years ago there was one in Ft. Steel, BC that still ran, it's doesn't now. 

Henner - We should not hijack Bill's thread. We could open a new one.
A fireless loco charged with steam would not work due to the rapid heat loss in a model. A paint ball tank might work. I just made a quick calculation and the range would be close to a mile (67cubic inches at about 3000PSi -> 6700 cubic inches at 30PSi). But you need to integrate the tank into a loco and also find space for the pressure regulators (probably two step). And then of course refilling the tanks.
Regards


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## Kovacjr (Jan 2, 2008)

Henner, Id think that the smaller tanks would be suitable, they are 9.5" and 12" long and are 1 15/16"" dia. 13 and 17ci at 3000psi. These are also rated fr Co2 and compressed air along with nitrogen

http://www.rap4.com/store/paintball...-refillable-compressed-air-tank-buttstock-kit


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## Amber (Jul 29, 2011)

Depending on the scale of the locomotive, the compressed air tank could be mounted inside of an outer shell detailed to look like the large compressed air tank that sat on the frame of the fireless engines. The tank screws into a coupling, similar to the way a small propane tank mounts to a torch head. You could probably use the coupling from a paintball gun for the connector. Then you would just need a pressure regulator of some kind and a throttle valve of some kind. You would also have to figure out some kind of way to lubricate the cylinders and valves.
A 2 stage regulator like an oxygen regulator should work to control the pressure to the throttle valve.


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## Kovacjr (Jan 2, 2008)

Actualy teflon pistons and valves would be needed as no lubrication will work. You can buy the regulator and its fully adjustable. Just another project I cant start for many years though.


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## HMeinhold (Jan 2, 2008)

Jason,
while waiting for my car today I did some rough calculations:
Assuming the tank with 13cu" @3000PSi:
Using the formula (pressure x volume = constant) you can get about 2600cu" @15PSi (probably the lower limit for a loco) out of the tank. This assumes constant temperature. The gas might cool down during expansion, but a heat exchanger might bring it more or less back to ambient.
Further assuming 1/2" diameter pistons and a 1/2" stroke, we get:
Volume needed for one stroke: Piston area x stroke. Piston area is (Pi x r squared) or 0.25" x 0.25" * Pi or approximately 0.2square". The volume needed for one stroke is then 0.2 square" x 0.5" = 0.1cu". One revolution of the wheel (assuming 2 cylinders) needs 4 piston strokes or 0.4cu" of air @ 15PSi.
With a wheel diameter of 1 1/2" one revolution of the wheel gives you (diameter x Pi) about 4.7" of travel. 
The tank can supply enough air for 2600/0.4 = 6500 revolutions. With 4.7"/rev the range of the loco would be approximately 2545',not too bad.
With a pressure of 30PSi the distance would be half of that. Early cut-off with air does not lead to condensation, so this might be another possibility to extend range. The question is how expensive is a tank refill?
Are my calculations correct?
Regards


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## Kovacjr (Jan 2, 2008)

Actually compress air refilling cheap. Anyone that does scuba or gas usually will refill it. My oxy tank was pretty cheap and thats a 40ft tank, have to look for the receipt but maybe it was 20.00


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## Amber (Jul 29, 2011)

If you're using a paintball gun tank, the refills are pretty cheap. I believe they use C02 for that. Also, you could have 2 tanks, that way you have an extra one to swap out for more run time.


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## redbeard (Jan 2, 2008)

As for co2, remember that it does not compress, it returns to a liquid at pressure. If you use liquid co2 the tank would have to be vertical or you would get liquid from the valve. 
Larry


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## Kovacjr (Jan 2, 2008)

Larry, the Co2 paintball tanks are designed for horizontal use. I think there is a syphon tube. aLL Pintball fields typically have a compressor for refilling the tanks with compressed air. Its the cheapest option. I used to work at Top Gun paintball back in HS as a ref on the field. We used to fill for free if you paid for admission to play. If just a refill the large tanks were like 5-6.00 but looking at their website today they are 8.00 now.

Now that I know it has the run time I will keep it on th elist of things to do.....some day


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## rwjenkins (Jan 2, 2008)

The proof of concept seems pretty straightforward. Start with an Emma, take off the boiler and replace it with the air tank and pressure regulator, and install teflon pistons and valves. If it doesn't work out, put the boiler back on and you still have a perfectly good Emma.


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## HMeinhold (Jan 2, 2008)

rwjenkins said:


> The proof of concept seems pretty straightforward. Start with an Emma, take off the boiler and replace it with the air tank and pressure regulator, and install teflon pistons and valves. If it doesn't work out, put the boiler back on and you still have a perfectly good Emma.


You probably don't need Teflon pistons as air does not "steam-clean" the cylinders. An oiler similar to what is used in air tools might work. But for a short test a couple of drops of ordinary oil should be sufficient
Regards


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## Amber (Jul 29, 2011)

The next question would be, how small of a regulator can you get?


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## Kovacjr (Jan 2, 2008)

Regulators are built into the tank threaded portion on the guns so you just need to adapt that and dial down to 15-20psi. They are fully adjustable with a allen key.


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## BigRedOne (Dec 13, 2012)

Where's Dave and his cannon car?

Could use the paintball tank to fire paintballs from the cannon!


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## Amber (Jul 29, 2011)

Hmm, not quite as complicated as I thought it would be.
As for a paintball cannon, I think a scale model of a railroad siege gun would fit the bill nicely...


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## Bob in Mich (Mar 8, 2008)

*We have a real one here in Michigan,It is at the Huchelberry.I will get You a picture of it in the spring.I think that Marty told Me it was used in a Refinery.*


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## Dave Meashey (Jan 2, 2008)

"Where's Dave and his cannon car?"

I don't know; could get a bit too messy. I think I will let someone else experiment with that idea.










If anyone tries to develop a working cannon car, please post photos.

Best,
David Meashey


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## Kovacjr (Jan 2, 2008)

There is a working cannon train, Carl Berg owns it and had built the train. His fried built the cannon.


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## Phippsburg Eric (Jan 10, 2008)

here is a video with a clip of a fireless loco working ... look at 0:54


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## Amber (Jul 29, 2011)

Nice steam footage! That fireless switcher had a big tank on it.


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## placitassteam (Jan 2, 2008)

Here is a photo of an air powered loco that I took in Creed CO.









This is the data sheet attached to it.









I have a few more views if anyone is interested.


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## Garratt (Sep 15, 2012)

40 cubic foot cylinder?

Andrew


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## Phippsburg Eric (Jan 10, 2008)

I recall seeing a similar (but larger) one on display near a flour mill outside of New Orleans


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## JoelB (Jan 3, 2008)

> 40 cubic foot cylinder?


Yes, if you figure that the diameter of the cylinder is about 30", with a length of 9 feet or so.


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## Garratt (Sep 15, 2012)

Yes, I over estimated the air tank diameter thinking the wheels were 36" diameter. It has a 36" wheelbase. 

Andrew


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## Naptowneng (Jun 14, 2010)

Great shot Winn, I saw that loco a few years ago on the way to Lake City another NG point of interest. Thanks for the memory

Jerry


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## Kovacjr (Jan 2, 2008)

The B&O Museum also has one on display.


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## Amber (Jul 29, 2011)

The size of the rivets on that compressed air tank is pretty impressive. I guess they wanted to make sure the ends stayed on the tank.


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## placitassteam (Jan 2, 2008)

Hi Amber, Yes and the boiler plate is about an inch thick!


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## k5pat (Jan 18, 2008)

*Compressed air engine*



Phippsburg Eric said:


> I recall seeing a similar (but larger) one on display near a flour mill outside of New Orleans


I believe Richard Jacobs (Trainmax) has that engine now. He may be planning to restore it.
It was used by the New Orleans Sewerage and Water Board.

See it here, second row middle:
http://lasta.org/?page_id=192


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## Totalwrecker (Feb 26, 2009)

I found these tonight... 
The last sez; Fireless and Soda ....

John


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## Amber (Jul 29, 2011)

Interesting little engines! I see the one in the middle picture looks like a compound , it has 2 piston rods riding on the same crosshead.


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## rwjenkins (Jan 2, 2008)

Interesting, I wouldn't have thought compounding would work on a compressed air locomotive because you don't get the same expansive properties on air that you do with steam, so at first I thought maybe they used four cylinders of equal size to get more piston area in a limited loading gauge. On closer inspection though, that does indeed look like a Vauclain Compound, with the smaller high-pressure cylinder on the bottom and the larger low-pressure cylinder on top. Definitely an air lokie too, with the uninsulated tank and radiator fins on the cylinders. 

The one in the third photo is interesting too. It was a fireless steam locomotive built by Baldwin for the Minneapolis Lyndale & Minnetonka Railway, which used a chemical reaction of caustic soda and water to generate the heat to boil water into steam (rather than simply use the gas from the soda reaction). The unit in this photo would have been enclosed in a wooden streetcar-style "steam dummy" carbody in service. More info on the "soda motors" here: http://streets.mn/2012/05/18/the-motor-line-and-its-fireless-soda-locomotives/


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## Phippsburg Eric (Jan 10, 2008)

Geez Richard you find one unusual stuff! That is crazy and amazing!


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## bille1906 (May 2, 2009)

In testing my compound Heisler, I found that it ran just fine on air, probably better than on steam as you don't have the condensation problem you do with steam. 
On the expansion of steam, It expands because it is under pressure. Compressed air )or any gas) will do the same thing. 
The power for the low pressure cylinder comes from two things:
the remaining pressure in the high pressure cylinder when the exhaust port opens and 
the air compressor action of the high pressure cylinder as it is exhausting.


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## Amber (Jul 29, 2011)

Hmmm, interesting.


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## fkrutzke (Jan 24, 2008)

Hmmm, also.

I guess I need to go back to school and get updated on the latest thoughts about thermo and fluid dynamics.


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## East Broad Top (Dec 29, 2007)

If you're ever in Cripple Creek, CO, take the Molly Kathleen mine tour. Besides being a really cool tour in its own right, it includes a ride behind an air-powered mine loco.It looks similar to the one shown above, but if memory serves, the ones used in this mine were home-built. 

Definitely an interesting idea using paint-ball canisters. 

Later,

K


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