Giant springs

One of the many Cheyenne Mountain features designed to protect the complex from a nuclear blast--or an earthquake--are these giant springs.

Placed under the complex's buildings, the more than 1,300 1,000-pound springs are meant to allow the structures to shift up to one full inch in any direction. Combined with a set of dampers, the springs are expected to protect the building, their contents and the people inside them.

These springs are pushed down significantly by the weight of the building. But from time to time, the springs must be adjusted to account for changes in the weight of the building and its contents.

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