The tunnels were also used during World War II as an operations bunker by the No. 1 Fighter Sector RAAF. The bunker was located in what was intended to be the City Inner Tunnel, access to which was provided by a wooden staircase in a shaft leading upward to Shakespeare Place. Women's Auxiliary Australian Air Force (WAAAF) personnel housed in this operations bunker collected information from radar and weather stations, as well as reports on air traffic, ship and troop movements collected from airports, army and Volunteer Air Observer Corps reporting posts. This section of tunnel was constructed using a cut and cover technique outside St James station, and connects to the tunnels in St James through pilot tunnels, accessible via ladder.