Underground Shelters (aka bomb or fallout shelters)
General
"At Hardened Structures we design our civilian underground Shelters primarily for nuclear weapons of medium to large size but also secondary for chemical, biological and radiological dispersion devices and conventional weapons. Also known as Weapons of Mass Destruction or WMD's. Although the design and dimensions are principally determined for nuclear weapons it can be established that a good underground nuclear bomb shelter also offers excellent protection against chemical, biological and conventional weapons along with most types of WMD's. In addition, with the ever increasing importance of having EMP (Electro-Magnetic Pulse) protection of Shelters, and other "HARDENED" structures, we provide State of the Art EMP mitigation both in terms of Bomb Shelter design engineering, which incorporates EMP shielding, and the usage of specialized EMP components.
The extent of protection for private civilian underground bomb shelters will, in general, be determined by Blast Overpressure measured in "Bars", (where 1 Bar equals 15 psi of applied Blast Overpressure) and initial radiation mitigation. Protection against the penetration of chemical, biological and radiological weapons is achieved by constant positive internal air pressure maintained by artificially filtered ventilation and air-locks. At Hardened Structures we use only Military Grade NBC air filtering systems, blast doors, blast valves and other shelter components.
U.S. National Planning Attack Scenario
The United States National Planning Attack Scenarios have identified the detonation of a 10-Kiloton (KT) Improvised Nuclear Device as the most likely incident of a nuclear bomb exploding within this country. As a reference, the Hiroshima bomb was 12-KT and the Nagasaki bomb was 22-KT.
In this scenario a 10-kiloton improvised nuclear device is smuggled into the center of a large metropolitan city inside a delivery van and detonated. Casualties are estimated to be in the hundreds of thousands with infrastructure damage within a bounded range of effect of 1 to 3 miles. It is estimated that 1 million + people will attempt self-rescue by evacuating and contamination in varying levels will encompass approximately 3,000 square miles.
There are several websites which have info on potential nuclear targets within the USA and the subsequent fallout path.
Planning an Underground Shelter
To properly plan, design and construct a customized underground bomb shelter for our individual clients we must first:
- Identify the threat levels; blast overpressure, radiation, etc.
- Identify the assets to be protected; people, possessions, food, water, etc
- Determine the length of the shelter duration
- Thoroughly examine the site and geotechnical conditions
- Be aware of all regulatory agencies having jurisdiction
Once this information is assembled a Protection Program and Cost Model Budget is then submitted to the Client for their review and approval.