I was watching a John Wayne movie where the rebs were stopping a train. The steam train was blowing black smoke and I was thinking that it should blow white smoke? Maybe the fuel used? Or is this Hollywood BS? I see this in many movies. I have an old toy steam engine that blows white smoke.
The fuel used was wood or coal in the boiler. Most of the steam lost exited below on the pistons that drove the wheels, or out the whistle
Coal powered steam engines emit black smoke. The "white smoke" may be steam. The steam is vented to increase draft for the boilers. black smoke Head on Aerial View of a Steam Freight Train Steaming Up with Black Smoke and White Steam black and 'white' smoke
Black smoke is unburned hydro carbons, be it wood, coal (or even diesel.) It comes when there's insufficient air in the firebox to completely combust the fuel. You see it when the loco is under heavy load, especially when starting off before draft is well established and will continue until the steam demand is reduced by getting the load up to speed. Very normal in the age of steam. White "smoke" is condensing steam, usually exhaust from the driving cylinders or whistle. Hot stuff, if you are standing too close. Yeppers, I KNOW about steam burns. That clip shows some black smoke while the engine is idling. Happens when the draft is turned down for some reason.
Coal fired steam locomotives used steam from the pistons in the smoke stack to create a draft. When parked, every now and then they would blow steam up the smoke to keep the fire going. Had a section of track wash out when I was a kid, 1940's, and fire went out on loco. They brought in a gasoline motor powered fan and put it on the stack to create a draft and get up a head of steam. Smokebox - Wikipedia With good coal, a good fireman, and a good man on the throttle, there was very little smoke. The fireman kept the fire spread out and hot enough that most of the particles were burned before it hit the smoke box. But to get more steam, due to starting up or a heavy hand on the throttle, meant more coal and more air and the desired clean burn might not be possible. We lived next to the tracks in the low rent area, and dad ran a butcher shop about 1/2 mile down the track and next to the depot. When I was about 5 , 1943 or so, the engineer would stop and the fireman would pick me up and put me next to the engineer and we would go to the depot, I would blow the whistle and dad would come and get me. Later we moved to the country, about 3 miles out of town, and the engineer would stop and we would catch a ride to town in the cab. They would turn the train around and we would catch a ride back in about an hour. Life was a little different in the 1940's and most lawyers were fairly honest. Good friend is a lawyer, said the real problem is that the 98% that are crooked give the honest 2 % a bad name
I was figuring it was the coal that made the black smoke. We have a local train and its diesel-electric. I used to go pick up people who got off the Amtrak train and it ran late most of the time and I was amazed at how many problems the trains and the tracks had. It was kind of funny the train stopped in the middle of nowhere and dropped people off at a concrete pad, it was in the woods.
Actually black smoke is predominantly carbon particles. It is often called soot and referred to in the engine industry and in regulations as “particulate matter” or PM. While .gov emission regulations would specify limits for PM emissions they are starting to deal with the size of the particles and not just the total mass as there are more significant health issues with very very small particles. Hydrocarbon emissions (HC) from an engine are generally in a gaseous phase and are not visible. In the case of Diesel engines first started in very cold temperatures, the exhaust is not very hot and some hydrocarbons can upon contact with cold air condense creating a fog, exactly like your breathe in cold weather and it is white. The diesel world calls it “white smoke” but as previously noted, with a steamer the white smoke is water vapor condensing creating a fog, or con trails if you prefer ;-) Fortunately, modern electronic engine controls mostly eliminate HC white smoke. AT
Think of it like this, BLACK coal smoke is raw unburned fuel, it is much the same as any other engine that runs on fuel! When Steam engines are running at the optimum, they should smoke a kind of greyish color most of the time, depending on the quality of the Coal. Now days, they have converted to run on #5 Diesel Oil, which dosn't smoke near as bad, nor does it coke the firebox or burner and tubes, so it's easier to keep clean and running hot! Another one people used to get all worked up over was War Ships, especially the Big Steam Turbine Powered Battle Wagons, but those didn't smoke all that much, and the trick was to run them hot and lean during the day, and at night, blow out the funnels and smoke boxes! The trick with ships was to keep things good and hot, which is one reason they had multiple boilers per shaft, so they could maintain the desired load with out burning up more fuel then needed! Bonus was they could also make their own smoke screens by dumping a combo of raw fuel and glycol into the exhaust of the boilers with the steam and really smoke things out!
