Black smoke vs white smoke

[ebtnut]

Black smoke is the result of incomplete combustion, which can be caused by a number of factors.  With old loco designs (principally pre-1900), the firebox was basically an open box with the grates at the bottom and the rear tube sheet as the front wall.  When working on the road with a big draft, some of the coal particles were just sucked through the tubes and up the stack without burning.  This caused smoke and was also inefficient.  More modern firebox designs added a brick arch over the firebed so that the particles had to move back towards the fire door before moving back to the front, giving more time for the particles to combust.  Later, loco designers added a combustion chamber as well, which essentially just moved the rear tube sheet forward a few feet to again allow more complete combustion within the firebox before the particles moved through the tubes. 

[rogertra]

Black smoke is the result of incomplete combustion, which can be caused by a number of factors.  With old loco designs (principally pre-1900), the firebox was basically an open box with the grates at the bottom and the rear tube sheet as the front wall.  When working on the road with a big draft, some of the coal particles were just sucked through the tubes and up the stack without burning.  This caused smoke and was also inefficient.  More modern firebox designs added a brick arch over the firebed so that the particles had to move back towards the fire door before moving back to the front, giving more time for the particles to combust.  Later, loco designers added a combustion chamber as well, which essentially just moved the rear tube sheet forward a few feet to again allow more complete combustion within the firebox before the particles moved through the tubes. 

UK steam have had a brick firebox arch and copper fireboxes since the late 1800s.  They also have had dampers from around the same time.  Firing a steam locomotive isn't just humping coal into the firebox it is an art. It involves knowing when to fire, how much to fire, where to place the cal in the firebox, what dampers to adjust and when, when to leave the firing door open and by how much and that's just fire management.  Lets not start on boiler management.


Cheers



Roger T