Mole hole

A mole hole, officially designated the Readiness Crew Building (RCB), is a type of structure built by the United States Air Force at former Strategic Air Command (SAC) bases around the country during the 1950s and 1960s. RCBs were located adjacent to an Alert Ramp, also called a "Christmas Tree", where Ready Alert aircraft were parked. These aircraft were initially Boeing B-47 Stratojet aircraft armed with nuclear weapons, augmented by Boeing KC-97 Stratofreighter aerial refueling aircraft. As SAC introduced newer bomber and aerial tanker aircraft into its inventory, the B-47 and KC-97 were later superseded by Boeing B-52 Stratofortress, Convair B-58 Hustler, General Dynamics FB-111 or Rockwell B-1 Lancer bombers, augmented by Boeing KC-135 Stratotanker or McDonnell Douglas KC-10 Extender aerial refueling aircraft.

Due to aircraft being parked at the "Christmas Tree" being on constant alert duty, the Strategic Air Command realized that they needed specialized buildings to house crews who rotated on alert duty. In 1958, Leo A Daly, an architect from Omaha, Nebraska, was hired to design buildings that would respectively hold 70, 100, and 150 men. These standardized structures would eventually be nicknamed "mole holes" due to the fact that the men would run out onto the "Christmas Tree" through corrugated steel tunnels attached to the lower level of the building when the alert Klaxon sounded. The buildings would house readiness crews and contained thick concrete exteriors, bathrooms, a briefing room for crew members, dormitories, several classrooms, a kitchen and a dining facility. Since crews were typically assigned on alert for seven-day periods, some installations would later incorporate outdoor athletic facilities on site, such as baseball fields or swimming pools, as well as picnic facilities where families could visit crewmembers on duty.

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