I just went over my combined engineman's roster from 1907 to 1960. There is no William (Bill) Pippenger on it. Perhaps he was loaned out to the NG from some where else, but he never had a seniority date out of Alamosa. He might have been a brakeman or a shop hand pinch-hitting.
The only wreck of note I can think of from that time period was 499 derailing at Coxo westbound Dec. 19, 1952. The engine ended up at about a 45 degree angle, the tender nearly on it's side. A bunch of wooden cars turned into kindling wood as the cars of pipe came charging in.