If you are referring to the photo of Salt Lake, Garfield & Western car 106, I may be able to offer an informed suggestion. This looks like a box car rebuilt for use as a line car, for stringing and maintaining trolley wire. The platform built on top of the box car roof allowed men to work on the overhead line. I think the SLG&W was a typical 600 volt DC trolley wire, like many city street car systems and some interurbans. The Butte Anaconda & Pacific (2,400 volt DC) and Chicago Milwaukee & St. Paul (300 volt DC) both used similar box car conversions at different times. One of the Milwaukee's box car rebuilt as line car was on one of the tracks outside the Avery, Idaho roundhouse in the early 1970s. I may have a slide of it.
CVM
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