Dominic Mazoch posted:Before the Challengers, the UP did purchsed 3 cylinder 4-10-2 and 4-12-2's. I think they wete converted to 2 cylinder.
Only the 2-10-2s were converted to 2- cylinder. ALL the 4-12-2 3 cylinders remained that way right through until the end of steam.
Too rigid and too complex for mountain service?
The 4-12 -2 locomotives worked out the final years, after the Challengers were delivered, in the Nebraska and Kansas plains. A number of the 2-10-2s were used as helpers in the Blue Mountains of Oregon. Remember that the UP didn't have many "sharp curves" in their mountains.
