The Fallout Shelter Sign is a sign of the past that is slowly disappearing from our urban setting. The sign marks the locations that would shelter 50 persons or more incase of a nuclear attack. The attacker at the time was the USSR and the US was full of fear. The Cold War was started shortly after WWII as the nuclear capabilities on both side continued to grow. The Department of Defense came up with the Fallout Shelter program in 1961. This sign was posted on thousand of building from schools, to churches to public buildings. Supplies where placed in the basements of these building to help those who survived if the worst ever happened. Thankfully the worst did not happen at the time. The program was designed by Robert W. Blakeley, Blair, Inc and Bob Schoonover.
The National Fallout Shelter Sign will be a familiar sight in communities all over the United States next year. It will mark buildings and other facilities as areas where 50 or more persons can be sheltered from radioactive fallout resulting from a nuclear attack. The sign will be used only to mark Federally-approved buildings surveyed by architect-engineer firms under contract to the Department of Defense. The color combination, yellow and black, is considered as the most easily identified attention getter by psychologists in the graphic arts industry. The sign can be seen and recognized at distances up to 200 feet. The shelter symbol on the sign is a black circle set against a yellow rectangular background. Inside the circle, three yellow triangles are arranged in geometric pattern with the apex of the triangles pointing down. Below the fallout symbol, lettered in yellow against black, are the words FALLOUT SHELTER in plain block letters. Yellow directional arrows located directly underneath the lettering which will indicate the location of the shelter.
Read a very complete history of the sign and program at this link by Bill Geerhart. It is a fascinating history of an implimentation of this national program.