Alco RSDs in Utah By | November 21, 2022 Email Newsletter Get the newest photos, videos, stories, and more from Trains.com brands. Sign-up for email today! Get Updates On the Utah Railway, three six-motor Alco diesels —RSD4 301, RSD5 306, and RSD4 302 — descend Soldier Summit with a loaded coal train in 1970. J. David Ingles photo