Ok, that makes sense, but would the firebox not getting as hot due to the thin air at high altitude not have an adverse effect on boiler heat/pressure?  I know that people coming to high altitude run out of breath in a hurry & often become dizzy & worse.  sports teams from the flatlands hate to play up hear & often require oxygen.

Greetings & salutations from snowy Colorado.  I'm a long time reader but totaly inept on the computer.  So here goes: I'm 69 years old,modeling in HO though no layout yet, the name of the layout will be the Aimless Mountain RR, a freelance based on the Colorado Midland.  One of the reasons for this choice was that the Midland used ten wheelers as road power & the only appropriate slide valve steamers are Bachmann's excellent versions.  However, they did use consolidations as helpers.  Are you listening MR B? there's a subtle message here.  lol  I really love this site, & want to thank you all for the informative,  helpful ,& entertaining, posts.  Special thanks to Sheldon, Gene, Jim Banner, Hunt, Rich C, Lanny, & many others. I do have a question for any of you rodders, current or otherwise.  Most of you are aware, I'm sure, that reciprocating engines lose three percent of their power per thousand feet of altitude. that amounts to 15 % here in Denver & a whopping 30% on Tennessee or Hagerman passes.  My question is, how would a steam engine be affected at the same altitudes?























































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Hi Royce, finally got on the board.  It's nice to know that I'm not the only one that's hung up on the CM. Unfortunately most of the Midland engines were built by Schenectady with wagon top boilers & the steam dome mounted almost against the front of the cab, not exactly the usual place in my experience. I had hoped that Bachmann would release Ma & Pa #23-24-25-26, the light consolidations but none so far. PLEASE MR BACHMANN ASK MR RILEY? We (those of us that are modeling late 1890's-early 1900's) need a slide valve connie with stephenson valve gear and Spectrum quality.  My understanding, Royce, is that Mr Riley likes Baldwin locamotives & the Ma & Pa so thats probably our best bet.