Its proper name was the Mark VII Attack Teacher and it was housed in a 3 story building in New London, CT.
In an age before computers could process graphics, vehicle and nautical simulations had to be done with models.
Trainees sat in a submarine mockup on the second floor, with a periscope jutting up into the third floor. On that third floor was a terrazzo tile floor–each square representing 1,000 yards–with remote control wired cars made up to look like little submarines.
Operators in the control room would plot enemy courses with the aid of mainframe computers.
The model was so accurate that it even duplicated the curvature of the Earth.
Click to Enlarge to 895 x 607 px:
Represented below is a closeup of the terrazzo floor, showing that one ship (#5) is within 2,000 yards of the periscope. Note wires extending from ships.
Source: Popular Science January 1950
