Okay, this will take a while.
I was an instructor at the USCG training center on Governor’s Island NY from 1979-1982. The main building for the training center was an older 3 story brick building. It was divided into 14 sections, labeled A through N. A much newer section was added on, that was O section.
The first deck from sections A through N were admin offices and classrooms. There was a library there too. The upper 2 decks were barracks (more like dormitory rooms). O section was all dorms. When I first got there, A-C, E-N sections both decks were for male students. D section, both floors, were for CPOs, both student and permanent party. O section deck 1 was for female students and permanent party. Deck 2 was for male permanent party 1st & 2nd class petty officers, and deck 3 was for male permanent party 3rd class petty officers and non-rates.
In each deck section was a large bathroom. Urinals with privacy separators, toilets in stalls, a row of sinks and mirrors, several washing machines and driers, and a large shower. 6 or 8 could shower at the same time each with their own nozzle. O section was different. The heads were larger and there were 2 on each deck, 1 at each end.
Changes came. The CPOs wanted nicer quarters and more females were coming as students and permanent party. So… female students were moved into both decks of D-section. The CPOs moved into O-section 1st deck. Permanent party female 1st & 2nd class POs shared the 2nd deck with male 1st & 2nd class POs, and female and male permanent party 3rd class POs and non-rates shared the 3rd deck.
O-section 3rd deck males used the head on one side of the deck and the females used the one on the other end. O-section 2nd deck, one head was male only. Because there weren’t that many females berthed there, they had a sliding indicator mounted on the door to indicate “Vacant”, “Male”, or “Female”. The only complaint I ever heard was some females griping about having a row of urinals in their head.* No gripes about a different gender walking in to the head already in use. And I heard of no problems with personnel going to or from the head in bathrobes or pjs.
So, at least there, it worked.
*It wasn’t my problem, but my opinion was “Why not just grow some ivy in them? They can water them by just pulling the handle.”