How much coal would be needed?

Model Railroader Prototype information for the modeler
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I am just now adding coal trains to my operating scheme. These trains are mainly pass throughs but I do have two coaling towers that will receive coal. I am considering adding a retail coal operation to the lumberyard that is already on the layout.

My question is how much coal would these coaling stations require. They receive anthracite coal. One tower is in the main engine terminal. Most of the steam operations are westbound from there. I have a transition era layout but typically a dozen steam powered trains a day head west with the next coaling tower being beyond the modeled portion of the railroad and it is 75 miles away. The power is combination of Consolidations, Mikados, Mohawks, Niagras, and Hudson. The other coaling tower is at the end of a lightly traveled branchline which I imagine to be 30 miles long. It uses a pair of Ten Wheelers and they combine to make two round trips daily.

I have no idea how to compute the amount of coal that would be burned during a typical week. I can’t even make a reasonable guess. I’d like to make a plausible number of deliveries to these two towers each week but I have no idea what would be plausible. I found a couple answers on Quora but I have no idea how reliable this is. One said 60 lbs. of coal a minute when running at 60mph. The other just said 9 to 13 tons per hour. Neither mentioned whether that is anthracite of bitumonous coal. Are these figures reasonable? The figure per hour seems like it makes more sense since the coal is burning whether the engine is moving, switching, or stationary.

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I’m certainly no expert on steam locomotives, but the tenders’ water capacity, in most cses, was the determining factor in the range of a steam locomotive. Most seemed to have had a range of around 100 miles between stops for water.

Like you, I didn’t find much information regarding coal consumption, although this LINK shows that N&W’s Class A 2-6-6-4s, using bituminous coal, was found that the maximum combustion of coal to be 7 tons per hour, in order to evapourate 14,000 gallons of water within that hour.

The As were considered to be modern locomotives, and due to the higher BTU output of Anthracite (between 13,000 and 15,000 BTUs per pound) versus high grade bitumous coal (between 10,500 and 15,000 BTUs per pound) your locomotives might have a slight proportional edge in range, although only the latter three of your listed locos would be considered modern…perhaps not quite as modern as the A, though.

Based only on the info cited above, with your next coaling tower located 75 miles from the first one, I doubt that most of your locomotives would need a top-up of their coal supply, and wouldn’t necessarily be out of water, either, although I could see that replenishing the latter might be wise.

I have two coaling towers on my layout, each owned originally by two separate railroads, but both now controlled by a third railroad. Due to the supposed lengths of each line (obviously, on most layouts, it’s dificult to have more than a few scale miles of actual track) the two coaling towers aren’t unreasonable.

For your layout, I’d recommend that you increase the theoretical distance between your coa

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Boilers produce horsepower. The work required of the boiler also determines its output. If you want to know how much coal a mainline coaling tower would need for supply in a given time-period, you need to figure out how much horsepower that tower needs to furnish between itself and the next opportunity to coal…the next coal tower.

If only it were so simple. Different locomotives steamed better than others of the same issue. Some were great steamers, some were pigs. Their crews knew the difference, too. But, each locomotive was expected to produce so much ‘work’ when it was placed into service. Some pulled long heavy drags, some pulled short and light commuter cars at modest speeds, some pulled ‘limited’ passenger trains at high speeds. Some went through coal quickly, some not so much. Some had 1000 mile tenders, or ‘coast-to-coast’ as some called them, while others were much more modest with perhaps 14k gals of water and 10 tons of coal at capacity.

You’ll have to craft a best guess. Was the traffic heavy, say 150K tons per day? Was there a lot of switching in between for the local freights? (Not too many coaling tower

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Obviously any estimates will be gross approximations.

Really crude way would be to figure how many engines the tower serviced per day, add up the tender capacities for those engines and that’s how much coal per day would be used if every engine had to be fully fueled. That would be the extreme top end of the range. If the tower service 15 engines per day with an average capacity of 18 tons per engine, that would be 270 tons/day. If they only half filled each tender that would be 135 tons per day.

The crew of the NKP 765 2-84 said the 22 tons of coal in the tender would last for about 250 miles (fairly light train). Runs of up to 200 miles without refueling were common. I have read the NYC 4-8-4’s with the huge coal tenders could go up to 400 miles.

I cannot imagine a modern steam engine fully using its coal load to go 70 miles. I would think that something in the 30-50% usage would be closer for a run of 70 miles and tenders with 16-20 tons.

Literally, YMMV.

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PRR trains on the Sandusky branch would take on coal at Marion,Oh… That was about the halfway point between Columbus and Sandusky around 100 miles.

The coal tower spans the double main and still stands today.

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Well, many coaling towers are rated by weight - how much coal they hold when filled up. If you have a 250 ton one, it holds 250 tons of coal. If it were completely empty, it would take 5x 50 ton carloads to fill it up (and someone would lose their job for letting it run completely out - unless it was a new installation). For keeping it topped up, you then have to figure the number, size, and work being done by the engines that use the coaling facility in a typical day. That’s where those ton/mile calculations come in. If 10 locos top off with an average of 10 tons of coal per day, then you need to bring in at least 100 tons of coal to stay even. A daily supply train is probably not the common way it was done though, if company service cars were used, there’s no real harm in a few loaded cars sitting there waiting to be unloaded as needed. One thing you quickly learn though is to never say ‘never’ - each railroad had their own way of doing things, so if you are modeling a specific railroad then you cna perhaps find some information on how they supplied their service facilities. If you’re doing your own thing, you can pretty much plan those trains however you want. There’s plenty of stuff to haul - coal, sand, supplies, and parts in; ashes, scrap, all the empties, etc. out.

–Randy

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Got a pencil?

BLW_fuel-data by Edmund, on Flickr

BLW_fuel-data_0001 by Edmund, on Flickr

Still more variables to add to Selector’s list is the grade (BTUs per Lb.) of the coal provided. Some railroads were known to get the bargain variety and the poor fireman had to deal with it.

Regards, Ed

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The other way to look at it is to reverse engineer the coaling tower. A railroad will have a storage capacity that is at least a couple days, just in case they have a supply interruption, they can still keep fueling engines. If you have a 200 ton tower and assume they have a 48 hour supply, then that’s 100 tons per day. If you assume a 3 day supply, then that’s about 65 tons per day.

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Few modern engines would burn anthracite in the first place (let alone culm!) even if it were mine-run cheaper. That fuel burns hotter, but slower, and does not perform well in most mobile applications. Conversely it is nifty for heating boilers, where a thin, wide fire with continuous gentle draft can be arranged, and long heat release without attention is a benefit.

The local dealer volume then becomes the question. Here the climate becomes important, as does the size of facilities or houses that are the likely source of consumption for space heat and DHW.

In many areas in the Northeast the switch away from solid anthracite fuel to oil heat or to natural gas accelerated dramatically in the immediate postwar years, probably thanks to Hitler and Doenitz. Their happy wanton destruction of coastal tank traffic led to extensive pipeline construction which facilitated local delivery of oil and of natural vs. synthesized process gas containing substantial carbon monoxide (the source of the terror in gaslights being ‘left on’ without being lit, or head-in-the-oven suicide)

Falling demand can be clocked in the northeast anthracite fields by the middle '50s, with one major milestone being the abandonment, and the reasons therefor, of the L&NE. Even so, there was an active market for anthracite in many locations up to passage of environmental protection and then enforcement in the early '70s. To my knowledge even today there’s no practical way to desulfurize anthracite cost-effectively for either heating or metallurgy – and that was that, even before electricity came into the game either conveniently or effectively.

There was still enough business in some northern New Jersey neighborhoods well into the '80s to keep coal dealers (and their fascinating specialized delivery systems) operating. But I suspect riding real-estate prices and rebuilding for better HVAC have wiped that out by now.

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According to this presentation, anthracite has lower sulfur than bitumonous (.6-.8% vs .7-4%). I read someplace that anthracite has the lowest sulfur content of any of the fossil fuels, but can’t find the reference.

https://purdue.edu/discoverypark/energy/assets/pdfs/cctr/outreach/Basics8-CoalCharacteristics-Oct08.pdf

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Some notes:

Coal_0001 by Edmund, on Flickr

Coal2_0001 by Edmund, on Flickr

Untitled_Panorama1 by Edmund, on Flickr

Coal2 by Edmund, on Flickr

Coal_0002 by Edmund, on Flickr

Regards, Ed