I worked on coal fired locomotives in limited museum service, oil fired locomotives in an intensively operated mountain tourist railroad, oil fired locomotives in limited museum service, and a bit of oil, wood and coal firing on different tourist and museum operations as a guest crewman here and there....... you can learn a lot by booming around.

dave

Texas State Railroad was a busy shortline when I worked there, BUT it was a comfortable, controlled environment. After 13 years with BN, this place was more like Gilligan's Island with trains.

Ferrovias Guatemala was a national system, narrow gauge, and I fired in excursion service from the Caribbean to the Contenental Divide, our mainline at that time was just over 200 miles. The way I explain it to normal people is that it's sort of like the trains at Chama or Durango, but we don't have to get volunteers to dress up like bad guys and pretend to rob the train. It was kind of like BN, too, with no hours of service law

Weather had pretty much no effect on how I fired, except when the rails were wet. A single wheel slip I'll follow with my firing adjustments, when the engineer shuts off, and throttles up again. If it happens over and over every few seconds, such as when you're out of sand or if your tires are due another turn or you have sticking brakes, I just sit there while the smoke boils up and clears every few seconds because you can't follow something like that.

Obviously as the weather gets colder, oil has to be heated until it flows and atomizes.

I've always worked where it ranges from comfortable to broiling hot, and it seems to me that if a black engine stands in the scorching sun long enough for it and the water in the boiler to heat up before you light it, you get steam a lot quicker with less fuel. When the tender warms up, obviously the oil flows better, but those ancient and barely functional Sellers lifting injectors don't like warm water, especially when they warm up, too. So before trying to pick them up, I shut the delivery line off and blow back through the tank --- I don't know why this works, but that's how the FIdeCA guys did it. When they warm up, you have to pour cold water over them before starting them. A Deutsche Reichsbahn dampflokheizer showed us that one.

I've also heard that internal combustion motors have a harder time in thin air at high altitudes, while steam engines do better, and it's my impression that this is correct. The basic firing technique I use in all conditions, all engines, all fuels, is the same. I was taught to watch everything all the time, and react to every change without letting myself get behind. The engine will tell you what she needs to BE HAPPY.

Altitude, two of the railways I have done oil firing on are rack railways up to 6000foot. In a way rack railways could be described as harder because of the change in altitude. If I remember the GCR loco's where at an even higher altitude. Generally you work things out at the average altitude of the railway.

When your doing some of the calculations they take altitude into account. It's no so much the oxygen content but the lower air density, pressure. Again powerful draughting like lempors or better are needed to pump the less dense air. You will find a turbo for internal combustion has to be of greater power to archive the same at altitude. The improved pumping action of the lempor provides the required air for combustion and the reason why I sometimes describe lempors as turbos for steamers. Also in the calculation you have to allow for the mass of steam from atomising and the increased evaporation for atomising in the draughting and evaporation calculations.

Water content has an effect on combustion. If there is to much then it will dampen or prevent full combustion. Ok cold air is denser and thus you need less volume.

The easiest way to describe the situation within a fire box which uses wet steam for atomisation is like an oil fire where the water used to put out the fire causes the water to turn to steam. This has a high volume and excludes air from entering the firebox. The fire goes out due to the lack of oxygen and air can then enter the partial vacuum. Then the whole cycle repeats its self. That's what the major noise is on an oil burner. If you use super heated steam less water is present and the cycle is reduced or eliminated. The result is also an improvement of approximately 10% in fuel saving.
When the weather is bad and the humidity high you draw more water in the air into the fire box and this has the same effect on the combustion in dampening it. The most noticeable time for this was when there was cloud on the top of the mountain and you had to change your fuel flow to keep the steam up. You fired to a slightly dirty stack which was the soot being formed by the water content. You also lose your fuel saving comparatively.

About the only calculations I ever did on oil firing were how much is my next check.

You fellas have definitely got me wanting to cherry pick some factual evidence to support my narrow minded opinions regarding one size fits all oil firing equipment and firing technique. Even better would be some controlled trials with you geniuses keeping records and doing some sophisticated calculations.

Only I think that's reinventing the flaged wheel. One of my all encompassing pronouncements is that the locomotive builders and major railroads knew very very well what they were doing, and that their factory firing setups are usually right on. I know damn well this kind of testing must have been done over and over already already.

Real interesting for sure --- Seems like a rack railroad with a steady grade like the Mount Washington would be the perfect place to test these effects of altitude, since that one factor varies a lot during the course of an hour or so, while train weight and speed do not to speak of.

So, does the reduced atmospheric pressure mean that you can gradually reduce throttle as you get to the top, since the steam can expand more ??? Can you bump back your fire, too ???

However much fuel you use, you have to fix your draft to get enough oxygen in there to burn it. As the oxygen thins out, do you have to crank up your blower to compensate ??? Does that result in too much cold air against your sheets and brickwork ???

I rode the Schafbergbahn in Y2K, and was their guest in the green engine, built (I think) in 1998 by Winturthur. I know she burned diesel through the typical setup I'm used to, but I think she had a stationary boiler type burner. The driver would bump the fire up a little, then get us rolling, then fix his fire. It didn't seem like he monkeyed with his settings very much at all.

Thanks for whatever you guys can tell me.

True story. If the local fire company calls asking if everything is okay you might have the oil valve open too far.