Re: WP&Y

Higher tractive effort yes, higher horsepower yes, but not necessarily higher drawbar pull. The C-21's had a factor of adhesion of 4.19 (weight on drivers divided by tractive effort). With 180 PSI, the FofA drops to 3.86 which makes for a slippery engine. The rule of thumb was to design for a FofA of 4.0.

The end result was that while #61 wouldn't necessarily be able to pull a longer train than a C-21, she should be able to pull the same length train somewhat faster up the hill, thanks to her higher boiler pressure.



Edited 1 time(s). Last edit at 04/05/2018 10:37AM by Kelly Anderson.