Not the first time I've been worng.
It’s a common misconception, and one perpetuated by our “esteemed” MSM. Many times we would be interviewed by a reporter about a mission here in the States, and plainly state we were US Army Transportation Corps and the vessel was a US Army LCU.
When the articles appear in print or the local news show, they invariably referred to us as “Corps of Engineers” and the LCU as a “Corps of Engineer barge”.