In some recent posts, people have been saying that tank engines have limited range, and I wondered, well, ya, they have small bunkers, but how fast does a single piece of coal burn, 3 second, 10 minutes, I just don’t know. Help Me Please!
Since a “piece of coal” would tell you nothing, bec ause we don’t know how hot the engine is, how big the piece is (coal ranges in size from pieces the size of a marble to the size of a grapefruit). Coal consumption is normally measured measured in tons per hour or tons per mile. It will be a while before I can dig up any stats.
Some British sites state rates of 3-4 lbs per hour per horsepower.
I found this information:
“See: Elements of Railroad Engineering by William G. Raymond, et. al. John Wiley, New York, 1923. p.157: Based on tests in 1904, simple freight locomotives consumed from 3.5 to 5 pounds of coal per horse-power hour. 4 lbs/hp-hr is only an efficiency of about 5% assuming a heat content of coal of 13.1k BTU/lb (U.S. Bureau of Mines). Internal combustion engines have an efficiency of about 25%. Both efficiencies are at steady speed and full power. Under actual operating conditions, the actual efficiencies will be significantly less.”
to talk about this in practical terms
i run a 12 ton narrow gauge 0-4-0 tank engine, usually with about 25 tons on the drawbar. the firebox is about 8 square feet. on a typical day i can cover about 8 miles on the 250 gallons of water i carry on board. we carry about 500 pounds of coal, enough to cover about 12 miles. It is necessary to dump the ashpan at 12 miles. A bigger tank locomotive would carry more coal and water but in my experience the range is about the same regardless of the size.
rear tank locomotives like forneys and mason bogies have a bunker and water tank on a frame extension and have additional range.
Okay, how long would a 4-4-0 burning marble sized coal would run, with 4 tons of it in the bunker? Also, how long would a larger 2-truck shay run with a full bunker?
Realizing the variation depending on the tonnage the engine is pulling and the terrain it is pulling it over, etc, etc, searching Google books I found a 1903 book that quoted the LV railroad as averaging 152 lbs of coal per engine mile, which would be about 52 miles for a 8000 lb load. Have no idea for a Shay. With a Shay your runs will be much shorter, 10-20 miles that would be a safe bet for the lower limit.
Based on toot toot’s numbers, it would seem that the fireman must have been kept pretty busy, especially on the bigger engines before automatic feeders were invented.
Many times I have come across statisics from bygone years that tell me that we simply haven’t got a clue what a real hard day’s work was like!
Dave
according to the American Locomotive by John White the typical 4-4-0 of 1875 weighed 32 tons and had a tender carrying 2 tons of coal and 2000 gal of water. the coal would typically be about the size of a baseball, two tons would give a range of about 25 miles. a standard Number 9 coal shovel holds about 16 pounds of coal
But wouldn’t how hard the locomotive is working, and type of coal make a difference? If I understand the workings of a steam locomotive correctly, the exhaust is used to generate draft. Therefore, the more the wheels turn, the more exhaust, the more draft, the faster the fire burns.
IIRC, anthracite culm burned slower than bituminous or lignite. (Its burning characteristics necessitated the wide, shallow Wooten firebox.)
Wasn’t there once a rule of thumb, two water stops to one fuel load?
I seem to recall reading a few years back that a fireman firing coal by hand was expected to be able to shovel 8 tons of coal in a given length of time as a firing rate, but I have forgotten the length of time. A little beside the point here, but at least it’s an indicator of the amount of coal an engine could burn.
The C&O ran it’s 2-6-6-6s and 2-10-4s from the Southern end of Ohio to the ports on the great lakes at the Northern end of Ohio with one coal stop at Columbus while pulling 160 loaded hopper cars. So it would seem that a tender full of coal would go a long way on a superpower engine. More than one hundred miles anyway.
If one were trying to figure out the range of a given locomotive I suggest looking to a prototype that ran the type you are interested in and see what actual use indicated. There are major variables in calculating coal consumption such as firebox size, depth of coal bed, speed and load on the engine. Also when one tosses in the compound versus simple factors it can get very complicated in a hurry.
Switchers and locals on the other hand may make several stops a day for water and fuel depending on where they were. Mine runs would often take coal from the tipple while they were working the cars at that location.
Generally road locomotives could get from one division point to another with out a fuel stop. Water needed to be replenished two to three times as often.
Consumption is also going to depend on the type of coal you’re burning – anthricite or bituminous. Anthricite, or hard coal, burns much more slowly than the softer bituminous, but also requires a larger firebox. That’s why the camelback was designed.
So, does anyone have a table of ‘typical ranges’ for different classes of steam locomotives?
I know it would vary based on gross tonnage hauled, grades, tender capacity, etc. but some ballpark figures would be nice to have…
IIRC anthricites long slow burn was a favorite for steel mills when making coke.
However when it came to steam boilers, bitmunous was the choice as it generated power more quickly.
As as you pointed out, sometimes it wasn’t a choice. So a larger firebox was made for camelbacks to burn anthricite coal.
As a side note: I read todays steam boilers in todays power plants are 30% more effiicient as the ones of the 40’s and 50’s. Coal is pre-crushed into smaller pieces in an effort to let it burn more efficiently.
I wonder how much more power we could squeeze out of a steam engine using todays technology? Could we have built a better steam turbine than the C&O M-1? Or the N&W Jawn Henry?
That’s basic physics/chemistry…surface area to volume ratio…something they knew 100 years ago, yet one wonders why it took so long to be put into practice.
Now lets add the cold facts of railroading…
Railroads didn’t buy top grade coal they usually used cheaper coal and that included slate and large chunk of coal the size of a small to medium size rock…A fireman could shovel 12 tons of coal during a 100 mile run-just because a locomotive had a mechanical stoker doesn’t the fireman didn’t use his scoop as needed in order to maintain a even fire.Make no mistake firing was a hard job.Remember you had to maintain your pressure to much the safety would lift to little you lost pressure.Now add slate,clinkers a poor engineer and you worked hard.In fact a crafty engineer could work his fireman harder then necessary.
Railroads did not typically used top grade coal; they usually ended up with the leftovers from the coal crushing and grading process. I remember reading once that the coal used on some Great Northern runs was so full of impurities that the grates became clogged with clinker, which had to be removed with a hammer and chisel.
One wonders how engine efficiency could have been improved if the railroads had used quality coal graded to the engine’s specifications.
Does anyone know how what type of coal was avalible in ontario, like Lake Simcoe area? And how fast would coal burn in a 4-4-0 with a grate area of about 16-ish feet?
There are no sources of coal in Ontario. Coal was imported from the eastern United States.