Articulation
by John Dziobko
Title
Articulation
Artist
John Dziobko
Medium
Photograph - Photo
Description
On August 7, 1956, the photographer captured a pair of N&W Railroad's Y6b-class articulated locomotives moving a heavy freight train past the passenger depot in downtown Roanoke. They were called articulated because of their flexible frame, which allowed the long locomotive boiler to flex through curves. Typical locomotive boilers were set upon inflexible rigid frames, limiting the degree of curvature the locomotive could traverse. But articulated locomotives would flex on a pivot point (note the slightly off-center front), solving the problem of negotiating curvature. It was a locomotive of the 2-8-8-2 type, meaning there were two sets of drivers, each with four axles, unlike typical locomotives with only one set of drivers. It recycled the steam from the back pistons to the front pistons, making it a "Mallet", named after the Swiss engineer Anatole Mallet (1837-1919), which combined the idea of locomotive articulation and compound steam use. The N&W, primarily a coal carrier serving coal country, was one of the last railroads to convert from steam to internal combustion diesels, building their own locomotives at the nearby shops into the late 1950's.
Uploaded
October 18th, 2014
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