Dragulajeeper wrote:
UGMiner Banks wrote:
Also, another question, What was the purpose of the huge (wide) smokestacks on some locomotives (Page 3 of this thread from Chris's SD trip). Why are some stacks straight, and some made so big and wide like that?
The wide stack is for locomotives that burn wood. The stack had a bunch of fins in it and the embers would bounce around in it until it cools off and then fly out so it does not catch the train itself on fire or start a wildfire, etc etc.
Additionally there are many variations within the basic styles (big wide stack for wood, narrow straight stack for coal or oil). The stack is the visible part of the drafting system for the fire. It is important for the stack and blast pipes (which sits under the stack inside the smokebox) to draft as efficiently as possible in order to create the ultimate burning conditions and have most of the fuel burn before it is ejected from the stack.
The most modern steam locomotives, and improved old steamers, have new blast pipes and nozzles which can also result in changes to the outward appearance of the stack. Dante Porta was the most recent designer to focus on nozzles and some locos running in the states have versions of his systems. See
http://www.spiritus-temporis.com/kylchap/
The next time you are around a steam locomotive with the front smokebox door open, take a look at the apparatus under the stack. You will see how the cylinders eject steam upwards into the blast pipe, in turn sucking the smoke coming through the flues with it. The shape of the stack is part of this whole system,
In old locomotives with simple blast pipes, you would often see a very tall straight smokestack. The height of the stack was needed to help the draft. As locomotives grew larger and the height available for the stack was compromised, the internal blast pipe design became more and more important.
Rob
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oh brother, now hes done it.
