Re: One Bizzare Movement

The ideal colour of the smoke emitted by a locomotive is light grey, no smoke means too much air, very dark smoke means too little air.
However it is also noticable that the exhaust is fairly clear with steam on but when the regulator is shut the black stuff comes back. This is a function of reducing the draft, and hence the amount of air, through the fire.
These days all we seem to get is "dubious" coal though I did find some real steam coal in the bunker of a visiting engine - leading to a comment along the lines of "dunno what the sh*t in the bunker is but can we have some more?" on the report card that day. It was real Welsh steam coal - similar to anthracite I believe - needless to say we're still using the hard stuff.....
G
(about 20 years experience of shovelling!)
P.S. the photographic community DEMAND black smoke which depicts BAD enginemanship (except after a heavy bout of firing)