The best of its class
That Atlas-F (also known as the SM-65F Atlas) was the final operational version of the Atlas missile as an ICBM (Intercontinental Ballistic Missile). The Atlas series was a culmination of a top secret ICBM project originally headed by John von Neumann. Built in the middle of the Cold War with the U.S.S.R, the Atlas series was designed to help the US response faster that the U.S.S.R., should the Russians attack the United States.
In part due to this interest for response speed, the Atlas F was designed to be extremely lightweight (for a missile). It used “balloon tanks” for fuel, which required pressurization for stability, or the Atlas would collapse under it’s own weight. So the Atlas rocket needed to be constantly kept pressurized, which is the main reason the missiles were stored vertically in underground silos.
There were only 72 Atlas F missile silo complexes built in the US.
The need to keep the Atlas F missiles pressurized required 24/7 computerized and human monitoring of the pressure gauges. But, it also kept the missile in an almost-ready state. If the missile was to be launched, the fuel cells would be filled with liquid oxygen, then the reinforced concrete silo doors would be opened, and the Atlas F missile lifted up by elevator out of the missile silo for launch.
By storing vertically, The Atlas F could be launched in ten minutes, five minutes less than the D or E.
The missile silos themselves were (and still are) engineering marvels of heavily-reinforced concrete, designed to protect the missile of over-pressures of up to 100psi. This was a huge improvement over the Atlas E facilities, which protected missiles to over-pressures of only 25psi.
Built to withstand nuclear war
The Atlas F series had an on-board computer, which necessitated a Command Center. Both the missile silo and the Command Center were build underground. The Atlas F missile silo complex was (and is) the most fortified of all the Atlas series facilities. The whole underground complex was designed to withstand any kind of bomb attack except a direct hit by a nuclear bomb.
The Atlas F was only in commission for about four years, from 1961 to 1965. Why? The Russians made a faster missile, and the USA in response switched to the Titan II series. Atlas F missiles were to be used for twenty more years for space launches, but this use did not require them to be kept in a permanent state of readiness, so use of the silos for missile storage was phased out.
But something built to withstand nuclear war doesn’t just fade away. Some of these incredible bunkers have been preserved by private owners for future use. This site is dedicated to one of those bunkers, which sits in the middle of a quite cornfield in Nebraska.