Spontaneous combustion.

[Murphy Siding]

     I hope I spelled that right.  DM&E had a little fire out near Wall,S.D. this week, that burned 20 or so acres of grass.  It's being reported that it was from spontaneous combustion of coal being hauled.  I know it's hot and dry in western S.D. in August, but hot enough to light up the coal?  How often does this sort of thing happen?

[clash]

I've read that it was'nt uncommon for wooden coal chutes to be destroyed by fires caused by spontaneous combustion of the coal.

[dldance]

     I hope I spelled that right.  DM&E had a little fire out near Wall,S.D. this week, that burned 20 or so acres of grass.  It's being reported that it was from spontaneous combustion of coal being hauled.  I know it's hot and dry in western S.D. in August, but hot enough to light up the coal?  How often does this sort of thing happen?

Anytime there is a very fine oxidizable powder there is the potential for "spontaneous" combustion.  The theory is that the heat dries the powder to the point that there is static electricity build up.  With sufficient charge, a spark will occur cuasing a very rapid fire or exposion.  This is a major concern in the design of flour mills and grain elevators.  Normally PRB coal has about 10% water content so the chances are remote- however, if it  dries out sufficiently...

dd

[cordon]

History Channel talked about spontaneous combustion of coal in the holds of ships.  OTOH, my childhood house in Massachusetts had a coal furnace and my elementary school had a coal furnace.  Different kinds of coal sat in the coal bins in each place.  Lots of houses in the town had coal furnaces, and we used to hang around the local coal company, hopper cars, and trucks at our little rail yard.  In all of that coal, I never heard of a case of spontaneous combustion.  The climate in MA has medium humidity, which may have had something to do with it.

O.T.  Later on, we converted our coal furnace to oil.  After several years, one day it gave out a huge "foom," and my mother called the gas company to come and convert it to gas, without even consulting with my father.

 

[jimrice4449]

If the "spontaneous cumbustion" was in a load of coal one would expect the fire to be in the coal car not along the right of way and, if it's a 100 ton coal car in a moving train, to light up far more than 20 acres.   My money is on sparks from a brake appilcation and typical news media "engage mouth prior to brain" syndrome

[Anonymous]

     I hope I spelled that right.  DM&E had a little fire out near Wall,S.D. this week, that burned 20 or so acres of grass.  It's being reported that it was from spontaneous combustion of coal being hauled.  I know it's hot and dry in western S.D. in August, but hot enough to light up the coal?  How often does this sort of thing happen?

Wow, you mean the DM&E PRB line is now up and running already?

Seriously, where was this coal from and where was it going?

As for spontaneous combustion, that's supposed to be a big problem for lignite once it dries out.  It was also a big problem for the Rosebud Syncoal.

FYI - Unless you can confirm that this fire started from spontaneous combustion of coal in a passing hopper, I would guess that the fire probably started from the usual lineside ignition souces related to brakeshoe or wheel anomolies.

[Poppa_Zit]

U.S. Department of Energy states:

"Spontaneous combustion has long been recognized as a fire hazard in stored coal. Spontaneous combustion fires usually begin as "hot spots" deep within the reserve of coal. The hot spots appear when coal absorbs oxygen from the air. Heat generated by the oxidation then initiated the fire."

[tree68]

Every year some number of farmers lose their hay barns as the result of spontaneous combustion of the hay.  The problem is green (damp) hay packed into a haymow, where the heat can build to the point that it lights off.

Entirely possible a similar problem could occur lineside where coal from overfilled hoppers (and/or less than perfect trackwork) may cause an accumulation.

[Murphy Siding]

Wow, you mean the DM&E PRB line is now up and running already?

Seriously, where was this coal from and where was it going?

As for spontaneous combustion, that's supposed to be a big problem for lignite once it dries out.  It was also a big problem for the Rosebud Syncoal.

FYI - Unless you can confirm that this fire started from spontaneous combustion of coal in a passing hopper, I would guess that the fire probably started from the usual lineside ignition souces related to brakeshoe or wheel anomolies.

I went back and looked for the story, it was in either the local paper or one of the TV channels.  I'll keep looking.  As I recall, the spontaneous combustion theory was per a quote by some guy named Kevin Shaeffer-whoever he is.  It seems like they had ruled out static electricity, and lightning.

     The coal is from the PRB.  Nanaimo Dale, I think, posted a link sometime back, that they were hauling some coal as some sort of test run thing.

     The last summer I lived in Gillette, Wyoming, 1983, I remember they had so many grass fires from sprks thrown off trains, that they had RR firecrews patroling the tracks.  I don't remember ever hearing of spontaneous combustion back then.  This time of year, grass fires are pretty common west river, train or no train.

[Murphy Siding]

Entirely possible a similar problem could occur lineside where coal from overfilled hoppers (and/or less than perfect trackwork) may cause an accumulation.

  I don't quite understand that.  Are you saying spontaneous combustion in a pile of coal on the side of the MoW?

[youngengineer]

Coal cars do sometimes start on fire, usually it is a smoldering fire inside the car, I have probably seen a half dozen such cars in my short career with the railroad. I woulsnt be able to say the type of coal or where the coal was from, but it does happen from time to time. I have seen them both let them smolder and other times they dig out the car to put it out.

[Murphy Siding]

Coal cars do sometimes start on fire, usually it is a smoldering fire inside the car, I have probably seen a half dozen such cars in my short career with the railroad. I woulsnt be able to say the type of coal or where the coal was from, but it does happen from time to time. I have seen them both let them smolder and other times they dig out the car to put it out.

OK  That would be weird!  After a visual runby, someone could get on the radio and tell you everything looks fine, except that one car that's on fire!

[tomikawaTT]

Coal cars do sometimes start on fire, usually it is a smoldering fire inside the car, I have probably seen a half dozen such cars in my short career with the railroad. I woulsnt be able to say the type of coal or where the coal was from, but it does happen from time to time. I have seen them both let them smolder and other times they dig out the car to put it out.

OK  That would be weird!  After a visual runby, someone could get on the radio and tell you everything looks fine, except that one car that's on fire!

Having lived for a time in Rapid City, with a job that took me all over the area (and entitled me to free coffee at Wall Drug,) I'll put my money on brake shoe sparks.  If a 100-ton carload of coal began to spontaneously combust, the damage would have covered a lot more than 20 acres!

OTOH, don't underestimate the potential for spontaneous combustion of coal to cause really serious problems.  If modern failure analysis is accurate, a bunker fire led to the loss of USS Maine - and the Spanish-American War.

Chuck (modeling Central Japan in September, 1964)

[youngengineer]

Coal cars do sometimes start on fire, usually it is a smoldering fire inside the car, I have probably seen a half dozen such cars in my short career with the railroad. I woulsnt be able to say the type of coal or where the coal was from, but it does happen from time to time. I have seen them both let them smolder and other times they dig out the car to put it out.

OK  That would be weird!  After a visual runby, someone could get on the radio and tell you everything looks fine, except that one car that's on fire!

 

It's the smoke and the smell that give it away. I've never seen one with flames shooting out, just some lazy smoke drifting out, and the smell of burning coal! You may not even notice if the train was moving by at 55 mph, its usually not a lot of smoke!

[solzrules]

Coal cars do sometimes start on fire, usually it is a smoldering fire inside the car, I have probably seen a half dozen such cars in my short career with the railroad. I woulsnt be able to say the type of coal or where the coal was from, but it does happen from time to time. I have seen them both let them smolder and other times they dig out the car to put it out.

OK  That would be weird!  After a visual runby, someone could get on the radio and tell you everything looks fine, except that one car that's on fire!

Having lived for a time in Rapid City, with a job that took me all over the area (and entitled me to free coffee at Wall Drug,) I'll put my money on brake shoe sparks.  If a 100-ton carload of coal began to spontaneously combust, the damage would have covered a lot more than 20 acres!

OTOH, don't underestimate the potential for spontaneous combustion of coal to cause really serious problems.  If modern failure analysis is accurate, a bunker fire led to the loss of USS Maine - and the Spanish-American War.

Chuck (modeling Central Japan in September, 1964)

Seems to me there was a debate as to whether a coal fire in the bunkers on Titanic played a role in weakening the hull.

 

[Murphy Siding]

Having lived for a time in Rapid City, with a job that took me all over the area (and entitled me to free coffee at Wall Drug,)

  Something tells me you had a government job, that involved ICBM's hidden in gopher holes.

[arbfbe]

Yes, spontaneous combustion if coal piles is a problem.  The coal can only be kept in the silos at the load outs for a limited amount of time before the danger of it catching fire becomes great enough for the mines to begin dumping it into trucks to haul out into the ground.  This is why MTY coal trains have a priority after any sort of line blockage.  If the RR does not have a train ready to load withing the safety window then the RR must pay for the dumping of the silos.

This is also why you can see large cats at coal generating plants rolling the stockpiles over now and then after the pile has been grounded for a while.

The loads in coal cars do catch fire from spontaneous combustion and the local fire department will come down and flood the car with water.  I have wondered what these cars weight after all the space between the coal chunks have been filled with water.

Part of what causes the combustion is the weight of the coal pile.  With a hundred tons or more of coal in a freight car which was loaded via the flood method you can imagine some of the coal is under a lot of pressure.  The size of most home heating coal bunkers probably does not have enough pressure to cause spontaneous combusion.  The coal bunkers in the Titanic probably held enough weight to compress the coal deep in the bunker.    

[nanaimo73]

Story-
http://www.rapidcityjournal.com/articles/2007/08/01/news/local/doc46b158107ed3e977539578.txt

The coal might have been from BHE-
http://www.blackhillscorp.com/index.htm

K Fuel-
http://www.bizjournals.com/denver/stories/2006/10/16/story11.html?jst=s_cn_hl

 

 

[CopCarSS]

So dumb question time...is it the coal, or dust from the coal that's igniting initially? I would understand the dust, but how much dust would be free to be "airborne" when it's a matter of the coal being compressed by tons of its own weight?

The reason I ask is because I've heard that Powder River coal is really terrible stuff to burn. I think the Boone & Scenic Valley got a load of it one time courtesy of Uncle Pete (or possibly back in the CNW days). One of the coal hoppers needed to be emptied to be repaired, so it was just easier to donate the load to the B&SV. As I recall, when they tried to burn it, they couldn't keep the fire going. I think in the end they had to resort to mixing small quantities of it with large quantities of better grade stuff.

Wouldn't it be hard for something that resistant to burning to ignite by spontaneously combustion?

[beaulieu]

I was thinking that the coal might have been heading for the cement plant in Rapid City.

 

The reason that the Boone & Scenic Valley had trouble burning PRB coal is also why a boiler at a coal burning powerplant is designed for a specific type of coal. It is also why Northern Pacific locomotives were built with larger fireboxes than those used on other roads locomotives of similar capacity. At a powerplant with a modern boiler the coal is crushed to the consistancy of Flour and then injected into the boiler's firebox just like a liquid. Also most steam locomotives are designed to burn "Pea" or "Nut" coal, rather than "Slack" coal. Slack coal includes fines of sand like consistancy, while the others are passed over sizing grates to eliminate the fines which will fall through the grates on a steam locomotive and clog the draft. 

[Murphy Siding]

I was thinking that the coal might have been heading for the cement plant in Rapid City.

From the story, I got the impression the coal was heading east, away from Rapid City.

[Anonymous]

No word yet on the rumor of an "unwilling seller" in a BNSF cap running away from the stacked ties earlier that day..........

[Murphy Siding]

No word yet on the rumor of an "unwilling seller" in a BNSF cap running away from the stacked ties earlier that day..........

Hardy-har-har.  I realize you are just joking, but have you looked at a map?  The fire was quite a distance from any "unwilling sellers".  In fact, if you checked into it, I bet you'd find a lot more "willing sellers" than "unwilling sellers".  This time of year, grass and forest fires are very common in western S.D., especially this year, when it's so dry.  That's why I found the spontaneous combustion idea interesting.