Not only gang showers but the toilets had no walls or doors. If you needed to take a dump you were there while others were brushing their teeth or doing the same thing as you, all in the open.
Also, I grew up where there were gang showers in Junior High and High School for both gym classes and the sports teams.
I wonder what they have now?
I’m sure they have stalls, which to me means that they can have fewer showerheads, and students have to wait longer to take a shower. My guess.