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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735th Railway Operating Battalion ~~ David W. Pirkle

Last know unit survivor!

PIRKLE, David Wiley David Wiley Pirkle, age 91, died peacefully with his three children by his side on Wednesday, March 8, 2017. Born October 21, 1925 in New Holland, Georgia. He lived through the great depression, and survived the Battle of the Bulge. David was an entrepreneur at a very early age and founded one of the last family owned scrap metal businesses in Atlanta.
Survivors include children: David W. Pirkle, Jr (Joyce); Nancy Pirkle Little (Charles), and Patricia Pirkle Coury; Grandchildren David W. Pirkle III; David Simpson (Shannon); Alisha Goldsworthy (Daniel); Elizabeth Pirkle Cook (Peter). Great grandchildren: James Connor Simpson; Julia Sierra Riley Simpson; Tyler Austin Goldsworthy, Ella Rose Goldsworthy; and Mason Oliver Cook.
A Celebration of Life service will be held at 1:00 p.m. Saturday, March 11, 2017 at the Peachtree Corners Chapel of Crowell Brothers
Funeral Homes & Crematory. A reception will follow the service. Relatives and friends are welcome to join us. On-line condolences may be made at www.crowellbrothers.com. Arrangements by Crowell Brothers Funeral Homes & Crematory, 5051 Peachtree Industrial Boulevard, Peachtree Corners, GA 30092. 770-448-5757. Blog post by Tom Luthan http://planettom.livejournal.com/328167.html Photos thanks to Tom Lutham and Mary Vernoy whose dad served with Pirkle