Re: Slide Valve vs Piston Valves on the K-27s

Traffic on the NG started dropping in the late 1920's and the depression of the 1930's just accelerated that traffic loss. The K-27's filled a niche between where the larger K's worked on the Mainlines, and where only the smaller C class engines could work on the light rail, light density lines. As a result, the K-27's really were restricted in where they worked, with their biggest theater of operations being the line from Montrose south, to Ridgeway, and over the RGS to Durango. As the RGS was particularly hard hit by the depression, I suspect that the Rio Grande could just not justify the costs of either finishing the 462, or rebuilding the 450, 451 and 460. By 1941 the use of the 27s had dropped to the point where the 458 and 459 were sold to Mexico, even though 459 had only recently had a complete overhaul.