Why do some steam trains blow white smoke and others black?(smoke not steam)?

Question

Why do some steam trains blow white smoke and others black?(smoke not steam)?

Answer 1

its depends on how well the coal is burning in the fire box.

if the coal burns efficiently the the smoke comes out white.

if not it comes out black.

Answer 2

My Dad was watching a movie and there was lots of black smoke coming from the loco, and he just shook his head.

He said if a locomotive was burning properly there was headly ever that much smoke, to make that much he said there was a way to inject sand into the stack, mostly for cleaning out accumulated deposits and it made a LOT of smoke, they do it for photo ops on the excursion trains nowadays.

The difference in color was stated as differences i the way the fire was burning and the fuel used, oil or coal and that is correct.

Answer 3

Some steam trains run on hopper oil same oil that lights some ships boilers. Some run on diesel and hopper oil (whiteish blueish smoke) mixture. others run coal (black smoke)

Answer 4

In a traditional steam engine, smoke and steam are exhausted up the chimney. So some of what you consider to be smoke is actually steam (or more accuratly, water vapour - steam is colourless), and this appears to be white.

Black smoke comes when the fire has just had fuel put on it - lots of waste material going up the funnel, or when the engine is working hard, if it is going easily then the smle will be white

Answer 5

The black smoke isnt steam its coal or whatever else they burn to boil the water to make steam.

Answer 6

as others have said,it's how much coal has been put in the firebox,too much makes black smoke,we tried to keep it greyish colour,keeping the fire 'hot'

Answer 7

Whether the smoke is white or black depends on the  mixture of fuel with oxygen.

Lots of white smoke---too much oxygen/not enough fuel

Black smoke=not enough air flow.

The same works for coal fired or oil fired steam engines, diesel locomotives, ships.