The main entrance to the complex is approximately one-third of a mile from the North Portal via a tunnel which leads to a pair of steel Blast Doors each weighing 25 tons. Behind the 25 ton blast doors is a steel building complex built within a 4.5 acre grid of excavated chambers and tunnels and surrounded by 2,000 feet of granite. The main excavation consists of three chambers 45 feet wide, 60 feet high, and 588 feet long, intersected by four chambers 32 feet wide, 56 feet high and 335 feet long. Fifteen buildings, freestanding without contact with the rock walls or roofs and joined by flexible vestibule connections, make up the inner complex. Twelve of these buildings are three stories tall; the others are one and two stories.
The outer shell of the buildings is made of three-eighths-inch continuously welded low carbon steel plates which are supported by structural steel frames. Metal walls and tunnels serve to attenuate electromagnetic pulse (EMP). Metal doors at each building entrance serve as fire doors to help contain fire and smoke. Emphasis on the design of the structure is predicated on the effects of nuclear weapons; however, building design also makes it possible for the complex to absorb the shock of earthquakes.
Blast Valves, installed in reinforced concrete bulkheads, have been placed in the exhaust and air intake supply, as well as water, fuel, and sewer lines. Sensors at the North and South Portal entrances will detect overpressure waves from a nuclear explosion, causing the valves to close and protect the complex. All of the buildings in the complex are mounted on 1,319 steel springs, each weighing approximately 1,000 pounds. The springs allow the complex to move 12 inches in any one direction. To make the complex self-sufficient, adequate space in the complex is devoted to support functions. A dining facility, medical facility with dental office, pharmacy and a two-bed ward; two physical fitness centers with exercise equipment and sauna; a small base exchange, chapel, and barber shop are all located within the complex.
Within the complex are all the utility systems necessary to make the facility functional. The primary supply of electrical power is supplied by the City of Colorado Springs. The secondary source or back-up power supply is provided by six 1,750 kilowatt diesel generators.
Water for the complex comes from an underground water supply inside Cheyenne Mountain. Today, 30,000 to 120,000 US gallons of water is deposited into four excavated reservoirs. Three of these reservoirs serve as industrial reservoirs and the remaining reservoir serves as the complex's primary domestic water source. All four reservoirs have the capacity to store 1.5 million US gallons of water.
Incoming air may be filtered through a system of chemical/biological/radiological (CBR) filters to remove harmful germs and/or radioactive and chemical particles. The fresh air intake is mainly from the south portal access which is 17 ½ feet high and 15 feet wide and linked to the north portal access which is 22 ½ feet high and 29 feet wide. The entire tunnel from north to south entry portals is nine-tenths of a mile long.
Updated: April 7, 2005