rehunn Wrote:
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> Fine, as long as you're rolling a 200 psi shell
> increase the thickness
> 15%, increase the pressure to 250 and cut down the
> cylinder bore size hence reducing the steam volume
> requirements. If you're slippery at 185
> psi you're flunking Steam Locomotive Design 1A.
> You reach 200 psi with a
> soak locomotive without all the bs of large hard
> to roll odd sized tubes, heater tubes all over the
> place and the associated other leaks. I don't
> deal with theoreticals, that's for people who
> don't wrench in the real
> world.
Hi Rich, I agree with you on the part of raising the pressure (if
practical) in the boiler. Yes, it certainly does make for a more
efficient machine. Decrease the cylinder bores and you still get the
same amount of t.e. with less fuel burned. Some examples were the
Frisco and their 20 4200 class Mikes. They ran at 235 lbs. instead of the normal 200 or 210 lbs.
The CN had some examples of 4-8-2 that ran at higher pressure (around
255 lbs. and smaller cylinder bores than other cousins with less
pressure in the boiler and larger bores.
As to steam theory, I have no problem with it being introduced here.
Myself, I had 28.5 years working in and around steam power plants.
The largest had 6 Riley boilers and 1 B&W and was rated for
1,060,000 lbs. of steam per hour. That's a MILLION SIXTY an hour at 800 lbs and 750 degrees.
So I have a little experience with Superheat. The 2 paid railroad
jobs that I worked both had Mikados with Superheat.
It was explained to me by knowledgeable folks in both the steam
and railroad industry that Superheat gives more volume, there are
tables to illustrate this if you look. I chose this quality of
Superheat because I felt that it offered a facet that most could
grasp.
Rich, to get back to your theory on the use of Superheat...show me one
4-8-4, 4-6-4, 2-10-4, 4-6-6-4, etc. without it. If you had a small
yard with out grades and you only had to move a car or two at a time,
then I agree, Superheat would likely not be warrented. Quincy RR.
2-6-2T was an example...they had a few miles of level running from
the town of Quincy, then a short but steep pull up to the WP
interchange. They elected not to go with Superheat and it was likely
the right decision.
