Re: Another K-27 question

Therein lies an interesting point....

It's absolutely 100% correct that total theoretical horsepower drops. But you only get that horsepower from the superheat if the locomotive is worked hard enough to need the horsepower - i.e. you're pulling a hard enough draft on the fire to generate the heat.

Loss of efficiency, similarly, is less (not zero, but less) at lower loads.

The Huckleberry is pretty flat. I suspect the lack is only noticed in fuel consumption. And that effect can be swamped by poor firing technique as well, which makes the whole issue kind of cloudy for a situation like this.

On the positive side, superheaters are maintenance intensive, so converting to a 'soak' eases the boiler maintenance required.

On the negative side, you have to be more careful about condensation in the cylinders.

I suspect (just based on theory, no practical experience) that removing the superheater elements will improve the draft, since you've removed a major restriction element, and that free draft probably makes it easier to hold steam with less fire.

*Disclaimer: little 'e' engineers do this speculation all the time, please feel free to chime in with your big "E" Engineer experiences with the real thing! I'm quite curious what the reality might be!

SRK

Kelly Anderson Wrote:
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> Tractive effort remains the same, but horse power
> drops (slower trip up the mountain), and
> fuel/water consumption goes up (shorter range).