Steam & Excursion > Another K2sa

Juniata out shopped the 1635 in 1912, and that's as close to an accurate date for this John S. Powell photograph taken at Narberth as it gets.
Photo credit the Library of Congress, Bruce Fales collection
Be of good cheer,
—Mac
www.lowellamrine.com

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All of these photos that you have put here on Trainorders have been great and appreciated.
John in White Marsh, Maryland

A truly well-crafted scene - Think how complex the signals were back then. Most were mechanical marvels.
Bob

Anyone know how to tell a K2 from a K2s?

The fact that so many are listed as both doesn't help either.
—Mac

timz Wrote:
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> Anyone know how to tell a K2 from a K2s?

Must have been approaching the big curves at Narberth, sure is straight ROW here. Love these photos from way before my time and the PRR Catenary.
Gonut

Saturated-boiler locomotives (K2, for example) do not have steam delivery pipes from the smokebox sides to the cylinder valve chambers. 

Superheated-boiler locomotives (K2sa, for example) steam delivery pipes from the superheater header (inside the top of the smokebox, between the smokestack petticoat pipe and the front flue sheet), diagonally though the smokebox side, straight down to the top of each cylinder's piston valve chamber. See photo of a K2sa dated 1939: Pennsylvania Railroad | Martinsburg, Indiana | Alco - Schenectady K2sa 4-6-2 #7166 steam locomotive | October 1939 | Francis B. Landenberger Palmer photograph / collection | National Railway Historical Society, Inc.

- Doug Debs



Edited 1 time(s). Last edit at 02/16/26 14:56 by DWDebs/2472.

That is so obvious, how did that get missed? And thank you.
—Mac

DWDebs/2472 Wrote:
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> Saturated-boiler locomotives (K2, for example) do
> not have steam delivery pipes from the smokebox
> sides to the cylinder valve chambers. 
>
> Superheated-boiler locomotives (K2sa, for example)
> steam delivery pipes from the superheater header
> (inside the top of the smokebox, between the
> smokestack petticoat pipe and the front flue
> sheet), diagonally though the smokebox side,
> straight down to the top of each cylinder's piston
> valve chamber. See photo of a K2sa dated
> 1939: Pennsylvania Railroad | Martinsburg,
> Indiana | Alco - Schenectady K2sa 4-6-2 #7166
> steam locomotive | October 1939 | Francis B.
> Landenberger Palmer photograph / collection |
> National Railway Historical Society, Inc.
>
> - Doug Debs

So 1635 is a saturated K2a? (Edson says "most" of the K2a's were built with superheat. Also says some were built with stokers, some of which were later removed.)

Not at the time of this photograph. The database misidentified this loco, it's a K2a.
—Mac

timz Wrote:
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> So 1635 is a saturated K2a? (Edson says "most" of
> the K2a's were built with superheat. Also says
> some were built with stokers, some of which were
> later removed.)