Steam & Excursion > Coal firing question

Just want to say, I'm from a bit of a younger generation and I've never fired coal before, so please excuse my lack of... well... sense. Over the years on this site I've often heard people mention keeping a deep bank of coal along the back of the firebox to keep it burning evenly/at the same rate across the entire firebed. I can tell this is going to sound like a very, VERY stupid question and probably get a good chuckle out of most of you, but when you say the "back" of the firebox, are we talking as though we are looking at the locomotive from the side? Or the opposite, from the point of view you'd actually be firing from, looking into the firebox from the firedoor? Judging by how the air flows through the firebox I would imagine that it is the former, but I figured it might be nice to get a clear answer and stop overthinking it.

Thanks,
James

The "back of the firebox", i.e. the "rear" is the part closest to the cab, fire door. Thus, the Fireman must maintain a thick "heal" or pile of coal all along the back/rear wall of the firebox. Another point, the natural forward vibration and draft tends to "vibrate" the firebed forward, i.e. away from the rear firedoor. Thus the Fireman MUST continually keep a thicker layer of firebed, including the rear heal, as the whole firebed slowly vibrates forward. This of course is all for hand fired locomotives. 

Stoker fired coal burners, MUST always maintain a thick heal around the firepot and along the rear wall of the firebox, in order to keep cold air from coming in around the firepot (coal distributing table assembly).

Thank you for the response. I knew I was thinking about it too hard... or maybe not enough, as the case may be.



Edited 1 time(s). Last edit at 01/27/23 14:52 by 5511_.

Yes, the ' back of the firebox' is the rear wall of the furnace.
You have two sides ( "side sheets"), the front sheet has many holes
that hold the firetubes.  Fire travels through the flues to the front chamber,
called the 'smokebox'....

So, we've described the 4 walls oftge furnace, 
The floor of the furnace, in coal burners, is made of flat, iron
rectangles each with many holes for air and oxygen for the firebed---
the firebed is flat burning-area that the coal rests on while it's burning.

Oil burning locos don't have a grate ----- the oil is burned on a flat fan-like
steam, jet-like array...and the oil burns in 'mid-air' ( a strong wind) in the firebox.

The top plate of the firbox is called the 'crown sheet'.  It is the most vital
part of the firebox, since it has only a thin layer of water to keep it from melting---
while withstanding 3,000 F flames and full boiler pressure.

The crown sheet is the most vital part of the boiler ---- it must be covered with water 
all the time --- the lowest level ( bottom) of the water level 'sight glasses' , 
is 3-inches over the crown sheet.   When in operation, you must have water
between the middle of the glass and the bottom 1/4 of the ( visible) glass.

Oh, by the way, do not denigrate your curiosity. 
Just because you don't know the "terms", or the science behind the way 
machines work, it's not a reflection on your ability to grasp the concepts.

We've all started from the 'awe' stage to the learning stage.
I've been around steam locos since 1947, when given a roundhouse tour
at North White Plains, NY.  

And, at age 83 ( nearly), I'm still learning new concepts and sophisticated
applications...  I continue ask many basic questions--- exploring for similarities from
the stuff I 'know' --- to the key aspects of new areas of learning for me.

So, also realize that the  "learning area" ( material that's new to us)  is so vast,
that each of us only 'knows' a tiny fraction of breadth of learning that has gone
before us.

An area where reality and complexity has so many forms, is RR air brakes.
 I ve had msny friends in the field of maintaining air brakes ---- and virtually
all the practitioners are very modest and a particular area of interest for them
is a "new" problem, that another brother will experience and up for discussion
and possible answers..

Air brake guys are some if the smartest technicians in the field, yet we can be 
stumped by very simple malfunctions..

Air brake specialists are some of the best, yet the most curious mechanics, and
they love to stumped by a fresh, unexplainable malfunctions or 
components, and combinations of troubled components.

One day, you'll be one of the "wise, old-heads"...... because you were curious..

​W.

 

wcamp1472 Wrote:
-------------------------------------------------------
> Oh, by the way, do not denigrate your
> curiosity. 
> Just because you don't know the "terms", or the
> science behind the way 
> machines work, it's not a reflection on your
> ability to grasp the concepts.
>
> We've all started from the 'awe' stage to the
> learning stage.
> I've been around steam locos since 1947, when
> given a roundhouse tour
> at North White Plains, NY.  

> An area where reality and complexity has so many
> forms, is RR air brakes.
>  I ve had msny friends in the field of
> maintaining air brakes ---- and virtually
> all the practitioners are very modest and a
> particular area of interest for them
> is a "new" problem, that another brother will
> experience and up for discussion
> and possible answers..
>

I actually am somewhat familiar with locomotives and boiler terminology, partially by being into live steam, reading a lot, and partially by lurking here for... well it's gotta be at least 15 or more years now (I only pay every once in a while when I've built up a list of questions). Like I said though, never done coal and I had been wondering about that one simple little detail for a while now. It amazes me that I've been learning about them for so long yet managed to dodge various little basic facts. A lot of "how" and "why" without enough "what" I guess. Air brakes are actually my biggest area of interest and again, I've learned a lot about it from lurking here as well as reading/watching other reference material. I even 3d printed a little triple valve just to see if I could make it work (as it turns out - depends on your definition of "working", still fun though). I actually do have some other questions if you've got the time to spare.

For some of your questions, you  could send me a PM, if you'd like.

Or, others might like the same issues and ideas that you bring up..

Wes Camp

Started a new thread about it. thank you.