
Note: This is work in progress. It is hoped that when this is posted, some one may come forward with additional information.
The Fairbanks Morse Switcher Locomotives were a rare breed. There were only 336 manufactured between 1950-1961. The Sierra Army Depot, at Herlong, had three. In 1976, the Sierra base railroad operated five days week from 7:30 a.m. to 1:30 p.m. The main purposes were to shuffle cars arriving from the Western Pacific which could range anywhere from two to ninety. I do not know when the depot acquired these locomotives, nor when they were discontinued by the depot..
The No. 1855, as seen above is now at the Nevada State Railroad Museum at Boulder City, Nevada. The No. 1857, is part of the collection of the Western Pacific Railroad Museum at nearby Portola, California.

Hopefully, with this article will flush out other information.
Tim