Re: Locomotives Question; What are these?

Earl Wrote:
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> While no definitive explaination has been found,
> investigation has found that Kevin and Casey are
> on the right track. 168 in colorado Springs still
> has it's set up in the smokebox. It consists of a
> coil of pipe going back and forth across the top
> of the smokebox. Indeed it seems to be an "air
> drier" for air operated appliances. The air came
> from the main reservoir source in the cab, went
> out to the smokebox drier, came back into the cab
> and was distributed to the sanders, air ringer and
> so forth. A lot of engines had them in 1930's, but
> they were removed in the 1940's. I think 478 in
> Durango still has the 2 elbows sticking out of the
> smokebox.

I'm guessing that since this arrangement was mostly gone by the 40's that it didn't effectively remove the moisture. While heating air in a closed system will lower the "relative humidity" (temp and RH are inversely proportional) the moisture content would remain constant.