What unit is this pin from?

Friend of the blog Tim writes:
 That's the unit crest ("distinctive unit insignia" -- DUI) worn by the Transportation Center & School, formerly at Fort Eustis (now Joint Base Langley-Eustis) and now at Fort Lee, VA, where Transportation, Quartermaster, and Ordnance training has been consolidated.
 I first saw this insignia in early 1975 when I was right out of basic training and assigned to the 1st Railway Detachment at Fort Eustis. My unit, however, didn't wear this insignia. Instead, we wore the TRADOC (Training & Doctrine Command) DUI seen here: Link Our shoulder patch was the diamond-shaped TC school insignia. I would have preferred to wear the TC&S insignia because it had railroad tracks on it. Unfortunately nothing we wore gave any hint that we were members of a railway unit.
By that point our little detachment was the last active duty rail unit in the Army and a year later our MOSs would be eliminated and limited only to the Army Reserve, and at the end of September 1978 the little 1st Rail Det disappeared for good.
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