What determines the color of a steam engine's smoke color? Watching some great old video I've noticed the color can change from dark black to almost a clear haze. I'm guessing there is a mixture of steam and smoke. But why does it change from time to time with the same engine?
Steamers and their Smoke Color
- Thread starter dricketts
- Start date
It depends one 3 factors.
1.How much fuel is being burned. More fuel means a darker smoke cloud. Less fuel means a whiter smoke cloud.
2.How fast it's going. Steam produces less smoke when it's going fast due to a hotter, cleaner fire.
3.Labor amount. A hard-working locomotive produces more smoke. A locomotive coasting or idling is not doing much, so it's smoke is less thick.
1.How much fuel is being burned. More fuel means a darker smoke cloud. Less fuel means a whiter smoke cloud.
2.How fast it's going. Steam produces less smoke when it's going fast due to a hotter, cleaner fire.
3.Labor amount. A hard-working locomotive produces more smoke. A locomotive coasting or idling is not doing much, so it's smoke is less thick.
TorenHynes
The Maple Leaf Forever
Actually, there's one other factor, the type of coal that's being burned. Anthracite coal gives a whiter smoke than bituminous coal or lignite.
cascaderailroad
New member
I like to clone a loco, and play with the config file smoke color, rate, and size to get alot of realistic smoke (not like the pitch black tornado funnel cloud). I also set Particle Effects to Maximum, as all my locos smoke bad like ALCO's 
Another factor is the firing style. If using the "little and often" firing style then, depending on the grate design, the **fire bed air supply** is not overloaded and enough air can get through. Black smoke sometimes indicates poor combustion probably due to not enough air from putting on a heavy or thick load of coal each shovelling session. Some boiler/fire grate combinations apparently worked best with the "little and often" trick while other grates needed a heavy or thick style. Coal quality also may dictate the need for heavy or light shovelling styles as well, so the fireman with thick black smoke may be doing the best he can with the type of coal and grate combination he has.
Smoke colour changes as a heavy fire burns so it is dark smoke after a shovelling session because the new coal may have partly blocked an air supply hole. The smoke colour becomes lighter because the air from the grate finds a better way to get to the new coal as more coal is burnt. Then becomes darker again with the next shovelling period and the cycle continues.
Grate styles determine the fire bed air supply thus the colour of the smoke. Locos designed for one type of coal would have that reflected in the grate/firebox design but may react differently if another type of coal, was used instead.
Smoke colour changes as a heavy fire burns so it is dark smoke after a shovelling session because the new coal may have partly blocked an air supply hole. The smoke colour becomes lighter because the air from the grate finds a better way to get to the new coal as more coal is burnt. Then becomes darker again with the next shovelling period and the cycle continues.
Grate styles determine the fire bed air supply thus the colour of the smoke. Locos designed for one type of coal would have that reflected in the grate/firebox design but may react differently if another type of coal, was used instead.
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