On average, what was the “standard” size lump of coal used in coaling towers? If I were to guess, it would be in the 3-4" OD range?
The reason for asking is that some of the tender coal loads in certain HO steamers look way oversized. This coal sizing chart has anthracite for stove coal in the ~2-1/2 X 1-1/2" range.
Thanks for the help…
Tom
Tom
Looking at pictures in my books it looks like coal was not sized uniformly at all. Some pics of hand fired locos have chunks that look as big as the scoop shovel all the way down to dust. On a stoker equiped loco the auger and breakers would crush it to powder to be sprayed into the firebox.
Another thing to look at is it hard coal (Anthracite) or soft coal (Bituminous). Some roads liked one over the other.
Pete
Hi Tom,
Railroads generally purchased the cheapest “run of mine” coal, which according to a current Dept. of Energy table goes through 8-inch holes in a coal sieve. Especially when locomotives were equipped with mechanical stokers this was considered adequate, because the stoker’s screw conveyors would also crush the coal lumps to about walnut size before they reached the firing table in the firebox. For hand firing “lump” coal would have been preferred, but even that is defined as passing through 5-inch holes.
So long,
Andy
Back around 1960 I saw one locomotive at a busy terminal (Yoshizuka, Fukuoka-ken) that had been fueled with the coal bricquettes usually used in domestic heaters - coal dust baked with clay, rather like what most of us use (in charcoal form) for barbecues.
The other locos present had been fueled with lump coal.
Chuck (Modeling Central Japan in September, 1964)
If a locomotive tender is filled with coal to a heaping mound, the big pieces will slide down the pile and stop at the bottom edge, while the smaller pieces remain on the top.
Thanks for the info, fellas. Sorry to take so long to respond.
Tom
It is interesting you bring up the subject as the one gent here had it right on at least according to my 94- year-old retired Wabash conductor friend. For their steam locos the Wabash used what they called “screen coal” that was the lowest grade coal the railroad could find but mixed it with what my friend calls “lump coal” which was a better grade coal. The individual that operated the coaling machine (coal dock as some call it) would have to mix two cars of screen coal for every car of lump coal. The coal was dumped btw the rails from hopper cars and hoisted into the coal dock by a conveyer system. This supply track went uphill past the coal dock. The loaded hoppers would be switched according to a switch list to get the right ratio of lump coal to screen coal and parked at the top of the grade. One by one, the coaling dock operator would ride them down to the right spot to unload them and then ride the empty on down the track to park for the switch crew or local to pick up later. To tell you how bad the screen coal was: my railroad friend said that train crews would often snitch lump coal from hopper cars out on the line for their cabooses and their mixed train combines–not necessarily Wabash coal. Yes, they had coal available in the yards for this purpose but the crews liked the lump coal better. It was easier to fire in the pot belly stove and put out more heat. According to what I understand his theory was the shinier the coal the better. LOL Clarence told me that the screen coal came form Decatur, Illinois which was the Wabash main yard, shops and hub. Most likely it originated in the coal fields of Illinois. Incidentally, Clarence and I recently coauthored an article on a Wabash mixed train in the Wabash Railroad Historical Society’s Banner magazine. I hope that Jim Hediger got a chance to read it. (Jim from Model Railroader was a former Wabash railroader.) I did not get a chance to see his video here but am looking forward to it. As you mig
One thing that has not been mentioned is that some kinds of coal contain more heat than others. The “calorific content” of coal has nothing to do with the size of the pieces; rather, it is related to the mineral content. I am not a coal expert, but I have fired actual steam locomotives in miniature (1/16 scale), so I know that some coal burns well and releases lots of heat, while other coal which may look the same burns poorly, releases less heat, and/or “clinkers up”, or forms slag deposits which obstruct the draft through the fire.
As a live steamer, my father bought small lots of coal from many places, including a mine in Trevorton, PA, and a dealer in England (supposedly Welsh coal), which he brought home on the airplane (50 lbs of carry-on luggage). The best coal, by far, was a gift from an older guy who had gotten it from parts unknown; it was so much better in ease of firing and heat content that we were spoiled for all other coal we could find after that.
The size of the lumps had nothing to do with how it burned, except to say that we did break up some with a hammer (messy work) as the firebox door was only about two inches wide. Nor did the appearance of the coal give a hint as to how it would burn.
Now, it is a fact that certain mines produced better coal than others, and the savvy guys on the railroad soon learned to identify the better coal by appearance, as well as source.
It is frustrating to be out on the road, with traffic behind you, trying to keep up steam pressure (and speed) with a tender full of bad coal . . . even in 1/16 scale. In HO scale, the volts and amps (watts!) are there on demand; one of the reasons why I like to model electric railroading.