Skip to main content

In the QUEEN thread, Hot Water mentioned the N&W used some of the best coal on the planet, and that was incorporated into their locomotive design.

On the NP, I believe some of their locomotives used lignite as fuel;  lowest quality coal, if I remember.

UP used Hanna Coal. 

Some NE railroads used anthracite, a very hard coal.

Others were into oil...

My guess is that each railroad had to keep in mind what fuel, and the quality of that fuel, when designing steam locomotives.

Original Post

Replies sorted oldest to newest

 

Some NE railroads used anthracite, a very hard coal.

My guess is that each railroad had to keep in mind what fuel, and the quality of that fuel, when designing steam locomotives.

NE railroads' definitely had anthracite's fuel quality in mind when designing their locomotives. 'Anthracite Roads' specifically designed locomotives with wider fireboxes to accommodate better burning of anthracite waste, known as culm.

The wide fireboxes were known as Wootten Fireboxes, named after their creator, and took up the entire width of the frame. 

This ultimately led to design of "Camelback" locomotives. While a number roads had camelbacks around the turn of the century, the camelback design was specifically popular with the Reading, CNJ, and other RR's in the coal region of northeast PA. These RR's stuck with the camelback design until it construction of new camelbacks was outlawed by the ICC in the 1910's.   

 

Need someone to fact check this part, but I think the Reading T1's technically sport Wootten fireboxes. I wonder if RBMN will use anthracite for 2102 or if it will share the bituminous coal supply they have for 425?

(I assume radial fireboxes and wootten fireboxes can use either type of coal, with each type of firebox firing better with the fuel type it was designed for... if not could somebody please correct me?)

@Prr7688 posted:

NE railroads' definitely had anthracite's fuel quality in mind when designing their locomotives. 'Anthracite Roads' specifically designed locomotives with wider fireboxes to accommodate better burning of anthracite waste, known as culm.

The wide fireboxes were known as Wootten Fireboxes, named after their creator, and took up the entire width of the frame. 

This ultimately led to design of "Camelback" locomotives. While a number roads had camelbacks around the turn of the century, the camelback design was specifically popular with the Reading, CNJ, and other RR's in the coal region of northeast PA. These RR's stuck with the camelback design until it construction of new camelbacks was outlawed by the ICC in the 1910's.   

 

Need someone to fact check this part, but I think the Reading T1's technically sport Wootten fireboxes. I wonder if RBMN will use anthracite for 2102 or if it will share the bituminous coal supply they have for 425?

To be correct, those railroads that used anthracite coal, did NOT use 100% Anthracite. Anthracite coal "burns" very, VERY slowly, i.e. it almost glows, and thus was mixed with at least 50% to 60% Bituminous coal. I seriously doubt that the RBNM will be using anything but Bituminous coal in 2102. 

(I assume radial fireboxes and wootten fireboxes can use either type of coal, with each type of firebox firing better with the fuel type it was designed for... if not could somebody please correct me?)

Correct.

 

I wonder what was the specific reason camelbacks were outlawed? l have read that being an engineer astride a boiler was not pleasant, nor a lone fireman, and l can see he might not get the word if the engineer promptly unloaded upon sighting an eminent cornfield meet.  I assume there was communication between them, but how reliable and efficient?

Why not research the camelback subject?

I wonder what was the specific reason camelbacks were outlawed? l have read that being an engineer astride a boiler was not pleasant, nor a lone fireman, and l can see he might not get the word if the engineer promptly unloaded upon sighting an eminent cornfield meet.  I assume there was communication between them, but how reliable and efficient?

According to Wikipedia, they were banned because of safety concerns, specifically a side rod breaking off and flying up into the cab where the engineer was. All new orders were banned after 1927.

The thing to remember about various types of coal in general is each type's chemistry. For example, Pocahontas bituminous, considered to be the highest grade bituminous coal you can get, burns hot and fast which is largely because of the increased amount of carbon gas content to solid form it contains. The larger amount of gas burns off much quicker and consumes the coal much faster since it makes up the majority of its content.

Compare that now to anthracite which burns very hot and very slow because the carbon in anthracite coal is mostly in a solid form with very little gas content. When burning the result is little to almost no visible flame, but it takes much longer for it to burn out. The reason it burns hotter than even high grade bituminous is because carbon in a more solid form combusts much more efficiently and effectively with most of the solid carbon being completely utilized to create heat versus a more gas form in bituminous coal where the process is much less efficient and you lose bits of combustible carbon material that never fully combines with oxidizers and heat to ignite and burn.  

In relation to the Reading with Camelbacks and T1 4-8-4s, enginemen often would tip hostlers a few dollars to give them 100% bituminous with the big engines to help with firing since the firemen found the mixture of anthracite and bituminous to be more trouble than it was worth. On the flip side though, the camelbacks particularly excelled in their use of anthracite because they were assigned to short fast commuter trains between Allentown, PA and Jersey City, NJ. The fireman would get his fire ready prior to departure in the large Wooten firebox of his Camelback and once off and up to trackspeed he would not touch it except to spot fire a few areas on the way into town. The same would hold true for the trip back. There is a great story David P. Morgan wrote in Trains magazine about such a process that Classic Trains periodically reprints. 

As a power plant professional I have dealt with most types of coal available in the US.  For stationary continuous firing there is even more to coal quality.   

In addition to heat content, volatile matter percentages, and ash percentages.   You need to worry about moisture percentages,  ash constituents particularly sulfur and mercury.   Even the best fuels can sometimes drive you nuts.  I specifically remember dealing with the aftermath of a plant burning a seam of generally good quality fuel that happened to have a higher than normal iron content.   Combined with their firing arrangement they ended up with several slagged over burners.  

Ash constituents can be all over the place.  In eastern bituminous ash is primarily calcium so it turns to concrete with the slightest bit of moisture addition after combustion.   Western bituminous however can have a large percentage of the ash as silica, so your fuel prep equipment is essentially getting sandblasted 24 hours a day.  

Yes, fuel quality is incredibly important.   Even on the small locomotive I fired as a volunteer we had an issue with fuel that tended to clinker and a newer volunteer that didn't understand the fire banking instructions.   When we went to pull out of town for an evening run and the fire box airflow plugged up, and steam pressure dropped.   We had to stop for safety while we cleaned out the fire and got steam built up again.   

@jhz563 posted:

... You need to worry about moisture percentages,  ash constituents particularly sulfur and mercury...

We don't need to worry about those specs in the steam locomotive business. They don't affect how the stuff fires in the locomotive. All I ever specified for our coal were the parameters I outlined above:

  • Heat value
  • Ash percentage
  • Fusion temperature

Coal brokers would occasionally ask me about moisture and sulfur content. My answer was always the same,"I don't care what those specs are because they don't matter in our application."

The high moisture, high sulfur coal was also bit cheaper, but it burned fine.

@Rich Melvin posted:

We don't need to worry about those specs in the steam locomotive business. They don't affect how the stuff fires in the locomotive. All I ever specified for our coal were the parameters I outlined above:

  • Heat value
  • Ash percentage
  • Fusion temperature

Coal brokers would occasionally ask me about moisture and sulfur content. My answer was always the same,"I don't care what those specs are because they don't matter in our application."

The high moisture, high sulfur coal was also bit cheaper, but it burned fine.

Yeah,  external combustion in locomotives applications is few and far between enough to basically get a pass on emissions requirements.   Pulverized coal combustion in power plants is itself becoming a dying knowledge base,  which is likely to continue as traditional power generation gets legislated out of business.   In a modern coal plant the emissions are quite clean, including the use of what is essentially giant catalytic converters.   

Getting back to OP's initial comments,  I can't imagine burning lignite in a locomotive.   That stuff is basically dirt that eventually catches fire.   It needs huge volumes of air to maintain combustion,  so if the NP used it in their engines I am sure they spent a great deal of time on exhaust/ejector performance.   

The only coal I haven't seen mentioned here in Powder River Basin, or PRB.  That stuff has been known to ignite in hoppers while still in transit.   It would be a  nightmare in a locomotive application.   I swear that stuff catches fire when you look at it the wrong way!

@jhz563 posted:

Yeah,  external combustion in locomotives applications is few and far between enough to basically get a pass on emissions requirements.   Pulverized coal combustion in power plants is itself becoming a dying knowledge base,  which is likely to continue as traditional power generation gets legislated out of business.   In a modern coal plant the emissions are quite clean, including the use of what is essentially giant catalytic converters.   

Getting back to OP's initial comments,  I can't imagine burning lignite in a locomotive.   That stuff is basically dirt that eventually catches fire.   It needs huge volumes of air to maintain combustion,  so if the NP used it in their engines I am sure they spent a great deal of time on exhaust/ejector performance. 

Sorry but, steam locomotives do not have "exhaust/ejector" items. In order to burn the lignite, a much larger smokebox was added to the front end. The CB&Q also tried burning lignite, with some success (I believe a little Bituminous coal was mixed in, just like with Anthracite). The NP didn't actually burn total lignite, but they did use the Montana Rosebud coal, which required much longer fireboxes. 

The only coal I haven't seen mentioned here in Powder River Basin, or PRB.  That stuff has been known to ignite in hoppers while still in transit. 

That's because it is already "powdered", i.e. mined and ground pretty fine. It is also VERY low sulphur.

 It would be a  nightmare in a locomotive application. 

PRB coal is WAY TOO fine for steam locomotive use.

 I swear that stuff catches fire when you look at it the wrong way!

Again, that's because it is so fine. Besides, even though PRB coal is very low in sulphur, it is also pretty low in BTU per pound. 

 

@Hot Water

Prb coal comes from seams 100 ft thick. Powder River Basin is the name of the geological area.  The Power River was so named because of extremely fine sand along its bank that resembled powder.

As to its combustible and physical form,  prb fuel is quite friable,  ie it breaks up easily when handled.   It still comes out of the ground in large lumps.   When dried in lab conditions it has just as much btu/lb as eastern bituminous,  but the high inherent moisture,  24 to 27% , results in an effective heating value of 6500 to 8900 btu/lb.   The reason for the lower value is that during combustion you have to drive off the moisture. 7800 to 8500 btu/lb were pretty typical as delivered numbers.

Prb has a very high volatile matter percentage compared to other coal's, around 34%.  The primary constituent of the ash is calcium.   Due to the friable nature you do get a lot of dust.   This results in a high surface area by volume.   

Anyone who has poured concrete can tell you it is exothermic while it dries,  i.e. it throws heat.  The calcium in prb ash does the same thing.   When you combine high surface area,  extremely flammable gas, an exothermic reaction,  and a slight breeze,  you get fire.

Fire in a hopper or barge can be extinguished with water or foam,  but foam definitely works better.   Fire on the coal pile can be handled with these methods and also creative bulldozing work.   Fire in a coal silo really sucks.  It's hard to put out and a serious pain to get the silo empty later.   Usual max safe dwell time in a silo is two weeks. Coal pile stack out for prb requires special techniques not needed for other fuels. 

Due to the combustible nature of the dust,  cleanliness in a prb fired plant is super important.   Much of the savings in reduced fuel costs is eaten up by extra cleaning costs. 

Yes the sulfur is very low.  This allowed some coal fired plants to operate longer without a scrubber by switching to prb.

Plant output rating is often reduced on prb.  This is because extra fuel is required to make up for the lower but rating,  and extra fuel requires extra air flow,  which is often not available.   

On the plus side, the ash is super clean and is a sought after commodity for concrete production. 

You can check my numbers since I am working from memory,  but I think they are going to be pretty darn close if not spot on.  I am primarily a rotating equipment guy now,  but I was a coal mill engineer for many years.   

Last edited by jhz563

@Hot Water

"Sorry but, steam locomotives do not have "exhaust/ejector" items."

I hope you are kidding.  The entire blast pipe arrangement combined with the geometry of the stack forms a converging/diverging nozzle.  Exhaust from the cylinders is arranged to create as much velocity as possible when travel along the inner surface of the exhaust stack.  This helps create a lower pressure zone in the smokebox area and pull exhaust gas through the boiler tubes.  Everything about smoke box design that is not directly related to superheating or other pressure parts components is related to efficiently moving the combustion exhaust.  Using either blower steam or cylinder exhaust steam as a motive force to pull exhaust gas through a nozzle, in this case the stack, is literally the definition of an ejector.  

I've been studying steam locomotives most of my life; I've been around people involved in steam locomotives most of my life. I have over 60 catechisms, books, and treatises on steam locomotive management, construction, operation and maintenance.

I have never once seen, heard or read about a steam locomotive's front end being referred to as an "ejector."

https://en.wikipedia.org/wiki/Giesl_ejector

Although not typically used in the US, this was a prime example.  

It may not be the name that everyone is used to, but an ejector is exactly what you call the overall device. 

Engineering description of an ejector  Essentially use of higher pressure fluid to move a large volume of a lower pressure fluid through a nozzle/diffuser is an ejector.  The process creates a partial vacuum to get the flue gas moving in the right direction, and pulls harder as more motive force is applied.  Thus the harder you work the locomotive, the more steam goes up the stack, the more air you can pull through the fire.

And yes I also been through the works of Chapelon, Porta, and Wardale.  My point was to say that there is no exhaust/ejector items in the front end of a steam locomotive is simply false.  In regards to the initial discussion on coal quality, the point was that lower rank fuels generally require more air and more residence time for combustion, so more attention would need paid to the exhaust moving system, than in a machine that burns higher quality, more forgiving fuel. 

 

I think it drives railroaders a little bonkers when non-railroaders come to the party and try to tell them the names of steam locomotives parts based on THEIR profession.  I had one guy try to tell me the headlight reflector was called a "nozzle," and a mechanical engineer try to tell me the name of the relief valve on the front of the steam chest was a "vacuum break." Might as well call the throttle the "accelerator" or the Johnson bar the "gear shift."

@smd4 posted:

I think it drives railroaders a little bonkers when non-railroaders come to the party and try to tell them the names of steam locomotives parts based on THEIR profession...

Agreed.

On a steam locomotive the device that blasts the exhaust steam up the stack is called the "Exhaust Nozzle." Above that nozzle and directly under the stack, is the "Petticoat Pipe." This inverted funnel directs the flow of exhaust steam from the exhaust nozzle up and into the stack.

There ain't no "ejector" in the picture anywhere.

Last edited by Rich Melvin

Non-railroader? Seriously?  I am not currently certified,  but I did hold a locomotive engineer's license for three years.    And yes, I am a mechanical engineer, so sorry if I look at the components and recognize the machine. 

All the parts described above are components of an ejector.  The only steam locomotives without these devices are fan equipped condenser locomotives such as the SAR Class 25C.

Then again at least I didn't call a couple of diesels strung together as a lashup!

Why you would call a headlight reflector a nozzle I have no idea.   

@Hot Water posted:

Don't you just love these discussions with a Power Plant Engineer, attempting to relate to a steam locomotive? I give up.

You may not see much relevance to power plant engineers attempting to relate to railroad steam locomotives, but I do.  I come to this debate as a fan of 19th century railroading.  Rich talks about how the petticoat pipe is used to direct the exhaust steam up the stack, but in my era its selling point was in helping achieve a proper draft in the locomotive boiler.  Getting the steam exhaust to head up the stack before the petticoat pipe had not been a problem.  Of course in that era they weren't operating locomotives at 200-300 psi.  Likewise the discussions about Wooten modifying fireboxes to burn anthracite mirror earlier developments where fireboxes were being modified to permit locomotives to burn bituminous .  (Actually a number of early locomotives operated on anthracite as the bituminous fields had not been reached.)  Plus in the 19th century you have the realization that what makes a good stationary or ship boiler may not necessarily be what creates a good locomotive boiler.

Locomotives such as the 765 or the J come at the tail end of an evolutionary chain which saw railroad locomotive boilers head off in a different direction.

Perhaps there are also some references you folks aren't familiar with:

http://www.trainweb.org/tusp/lempor/lempor.html

http://www.trainweb.org/tusp/l...r/lempor_theory.html

http://www.trainweb.org/tusp/lempor/app_a2.html

I was going to post excerpts from "The Red Devil and other tales from the age of Steam " , by Wardale, but I couldn't find my copy last night. 

The synopsis pages on the ultimate steam page, which I posted links to above, are actually quite good, and somewhat easy to follow the concept even for non-engineers.  And yes, the term ejector is used extensively. 

Steam locomotive development did not all come to a hard stop in 1945.  Many improvements,  particularly to exhaust systems, continued to recent times, including work performed on one of the cog locomotives at Mount Washington, and at least one of the Grand Canyon locomotives. 

Last edited by jhz563
@jhz563 posted:

Non-railroader? Seriously?  I am not currently certified,  but I did hold a locomotive engineer's license for three years.   

I should have said "steam railroaders."

Your reference to "ejectors" are to very specific front end designs. They are not referring to the standard front end arrangement as an "ejector." If you used that term around steam railroaders, you'd be laughed out of the room.

In addition to the authors you reference, I suggest you further your reading by looking into Grimshaw, McShane, and J.W. Harding.

 

A Lempor exhaust system was tried on 3985. it was an abject failure. After a couple of trips where she did a rolling tribute to Vesuvius erupting, the Lempor was ripped out and unceremoniously tossed in the scrap dumpster behind the Cheyenne shops. Maybe Otto Jablemann and the engineering department at ALCo got it right, after all.

I am told that Steve Lee gave a cogent and concise  assessment of the Lempor system. Unfortunately the adjectives and nouns he used preclude it from being quoted on this site.

@smd4 posted:

I should have said "steam railroaders."

Your reference to "ejectors" are to very specific front end designs. They are not referring to the standard front end arrangement as an "ejector." If you used that term around steam railroaders, you'd be laughed out of the room.

In addition to the authors you reference, I suggest you further your reading by looking into Grimshaw, McShane, and J.W. Harding.

 

My first couple years were operating a Porter 0-4-0, converted to 2-4-0 and tender.  Not big or fast by any means but all the concepts are the same.   Whether folks here want to accept different view points or not, I do have relevant experience and knowledge in steam locomotive operation.

And I love to learn so I will gladly look into buying some more reference material.

And yes steam railroaders and mechanical engineers are not the exact same people.  I feel lucky to have been both.  

 

I remember hearing anecdotally about the failed UP experiment.  When doing something new it is design, test, analyze, and repeat.  If analysis and repeat are left out the development stops.  If she was spouting fire, and I am not at all familiar with what actually happened, then the exhaust ejector system was working too hard and actually needed detuned, or other changes made.  

I am not looking to fight online with anyone.  But I am also not willing to be written off as side show entertainment that doesn't know anything about what I am saying.  I fully recognize that the terms I am using may not be familiar to everyone, and I always have more to learn.  But in no way does that mean that anyone else knows everything there is to know either.  

Frankly the tone of the response to my comments on this thread have largely been condescending.  This forum is a great place to learn and exchange ideas.  I won't stop trying to do both.

Jhz563, I have all three of the books you showed in your post above. I have read each one, cover to cover, at least twice. However, reading those books does not change the fact that modern American Steam locomotives do not have an "ejector."

Yes, I guess you could assign that term to the overall process of exhausting steam up the stack and using that energy to draw a draft on the fire, but when working in the steam locomotive world, that term is simply not used. As Steve said above, if you use that term around steam locomotive people, you'll be branded as one of those egghead "engineering types"  when it comes to steam locomotives.

My point is that you have to use the lexicon of the industry you are working in if you want to be understood in that industry. In stationary power plant steam service, perhaps the use of the word "ejector" is commonplace. It is not commonplace in the steam locomotive industry. That doesn't make it wrong, it's just different.

@Rich Melvin posted:

My point is that you have to use the lexicon of the industry you are working in if you want to be understood in that industry. In stationary power plant steam service, perhaps the use of the word "ejector" is commonplace. It is not commonplace in the steam locomotive industry. That doesn't make it wrong, it's just different.

In the same way, a physicist would look at the design of the smokebox and insist it's application of Bernoulli's principle  ! 

I found an interesting article on the Grand Canyon RR's use of Lempor exhaust on their steam locomotives to better draft the vegetable oil fuel. (It talks about Bernoulli's principle in the design). 

I've experienced this a few times in the workplace where people are talking about the same thing but are at odds with the terminology used in the industry. One of my coworkers would get upset when people used the term 'imaginary power' (widely used term in electrical engineering) instead of using the term 'reactive power' (used in the utility/power industry). While they reference the same thing, 'reactive power' is the more professional term for the industry. While I see both sides of the converstation, I agree with Rich and HW that 'ejector' is not the terminology that should be used when talking about steam engine exhaust, even though the smokebox design can be described as such from an engineering standpoint.

Hope this didn't add fuel to the fire (pun intended)

Last edited by Prr7688
@Rich Melvin posted:

Jhz563, I have all three of the books you showed in your post above. I have read each one, cover to cover, at least twice. However, reading those books does not change the fact that modern American Steam locomotives do not have an "ejector."

Yes, I guess you could assign that term to the overall process of exhausting steam up the stack and using that energy to draw a draft on the fire, but when working in the steam locomotive world, that term is simply not used. As Steve said above, if you use that term around steam locomotive people, you'll be branded as one of those egghead "engineering types"  when it comes to steam locomotives.

My point is that you have to use the lexicon of the industry you are working in if you want to be understood in that industry. In stationary power plant steam service, perhaps the use of the word "ejector" is commonplace. It is not commonplace in the steam locomotive industry. That doesn't make it wrong, it's just different.

Rich,

 I recognize the terms I was using are not steam railroading standard lexicon.  What got me was the very dimissive "Sorry but, steam locomotives do not have "exhaust/ejector" items."  It just isn't true. From that statement I could have left out the word ejector and been told a locomotive doesn't have an exhaust system.

I purposefully used two terms to be more inclusive.  Being told that something isn't there, that clearly is, or to have someone assume you don't have relevant experience, in both cases just to be dismissive, just strikes a nerve.  And frankly it goes against the rest of the flavor of the OGR forum.  I try to be supportive in all my forum posts as are most others.  This exchange has been different.

Honestly back when I was on the footplate and responsible for smaller industrial boilers at the same time I often thought that it would do stationary boiler operators a world of good to spend a weekend in the cab and get a hands-on feel for the relationship between load (throttle and cut-off combination), feedwater admission, drum level (boiler water level in the sight glass), and how their actions affect these items.  Based on these conversations it is also clear to me that there is some good knowledge transfer possibilities from Power Plant operations back to Steam locomotive design and maybe operation, but mostly design.  

Edit - This has also demonstrated to me that such knowledge transfer may not be possible due to negative attitudes towards anything or anyone that didn't spend decades within the small existing prototype steam locomotive community. End of edit.

It has been 10 or 15 years since I had a throttle or coal shovel in my hands.  One thing this conversation has done is rekindle my interest in prototype design.  Now where the heck did I stash those books?....

Last edited by jhz563

Add Reply

Post
×
×
×
×
Link copied to your clipboard.
×
×