P10 Underground Shelter

Discussion in 'General Survival and Preparedness' started by melbo, Jul 29, 2006.

  1. melbo

    melbo Hunter Gatherer Administrator Founding Member

    Came accross this Monster Shelter.
    $90,000 new...

    <TABLE class=contentpaneopen><TBODY><TR><TD class=contentheading width="100%">P10 Underground Bomb Shelter </TD></TR></TBODY></TABLE>

    <TABLE class=contentpaneopen><TBODY><TR><TD vAlign=top colSpan=2>

    P10 Bomb Shelter​

    The P10 is a third generation disaster shelter designed and developed by Walton W. McCarthy, M.E., author of PRINCIPLES of PROTECTION, U.S. Handbook of NBC Weapon Fundamentals and Shelter Engineering Standards, Fifth Edition, 2000, which is the United State’s bible on shelter engineering. He is the chief engineer of RADIUS ENGINEERING INC., with over 25 years experience design&shy;ing "high- tech" disaster shelters. The book is dis&shy;tributed by The American Civil Defense Associa&shy;tion (TACDA) in Draper, UT and is known in the industry as P.O.P. The P10 was designed using CAD (computer aided drafting), CAE (computer aided engineer&shy;ing), and FEAM (3-dimensional finite element analysis and modeling). A shelterist in the P10 under heavy, direct effects from two 1-MT nuclear weapons, has at least the same probability of survival (99.7%) as a person living and working in peace&shy;time. The paraboloid shape of the P10 allows it to be a true pressure vessel for resistance to high external pressure. The P10 shelter system is a third generation design and is based on 10 years field experience with McCarthy’s successful TBC6, and ES10 fiberglass underground shelters. The P10 is much easier to enter and exit with its offset entranceway. The hatch at ground level of the P10 is available in several different levels of threat resistance. The geometry of the P10 allows the much-preferred offset entranceway. This has the same radiation geometry shielding as a 90-degree entranceway plus it provides the most efficient escape for moisture and heat.

    P10 Underground Bomb Shelter Photos
    P10 Underground Bomb Shelter Drawings
    For more information about the Radius Engineering product line of bomb shelters, storm shelters, underground power plants and multi chamber air filtration, please contact Walton McCarthy here.

    The P10 Underground Bomb Shelter is designed to protect shelterists from at least two 1-MT nuclear blasts at ground zero. ​

    P10 underground bomb shelter interior view (1) ​

    P10 underground bomb shelter interior view (2) ​

    P10 underground bomb shelter interior view (3) ​

    P10 underground bomb shelter exterior view (1) ​

    P10 underground bomb shelter exterior view (2) ​

    P10 underground bomb shelter exterior view (3) ​

    • Structural Fiberglass Paraboloid
    • MCAS Air Filtration System
    • Toilet, Shower and Septic System
    • Battery Operated
    • Decontamination
    • Communications System
    Nuclear Weapons
    Chemical Weapons/Accidents
    Nuclear Power Plant Accidents
    Nuclear/Chemical Terrorism
    Power Plant Failures
    Fires and Famines



    The P10 is a totally self-contained 40-150 psi paraboloid (egg shape) underground disaster shelter designed to protect 10 adults for long periods or 20 people for short durations such as during tornadoes. The product was specifically designed and developed to protect people during and after disasters such as tornadoes, hurricanes, earthquakes, storms, forest fires, power failures, nuclear power plant accidents, nuclear/chemical terrorism, and full-scale protracted nuclear, chemical and biological war. A tremendous effort has been made to think of every conceivable incident that shelterists could face in the P10 shelter. Many geometrical shapes were experimented with before finalizing the P10. The P10 includes the fiberglass paraboloid structure, fiberglass entranceway, fiberglass/composite hatch, HEPA filter, 45 gallon fiberglass septic tank, 500/1000 gallon fiberglass water tank, fiberglass center floor beam, fiberglass counter, fiberglass shower wall, fiberglass battery housing, aluminum carbon filter housing, toilet, floor, fourteen 12- volt deep cycle batteries, air blower, gray water tank, all wiring, all plumbing, etc. The P10 requires approximately 3 man-hours hours to connect the entranceway and water tank hoses to the shelter

    The P10 Underground Bomb Shelter provides family protection from WMD's ​

    The P10 is a third generation disaster shelter designed and developed by Walton W. McCarthy, M.E., author of PRINCIPLES of PROTECTION, U.S. Handbook of NBC Weapon Fundamentals and Shelter Engineering Standards, Fifth Edition, 2000, which is the United State’s bible on shelter engineering. He is the chief engineer of RADIUS ENGINEERING INC., with over 25 years experience design&shy;ing "high- tech" disaster shelters. The book is dis&shy;tributed by The American Civil Defense Associa&shy;tion (TACDA) in Draper, UT and is known in the industry as P.O.P. The P10 was designed using CAD (computer aided drafting), CAE (computer aided engineer&shy;ing), and FEAM (3-dimensional finite element analysis and modeling). A shelterist in the P10 under heavy, direct effects from two 1-MT nuclear weapons, has at least the same probability of survival (99.7%) as a person living and working in peace&shy;time. The paraboloid shape of the P10 allows it to be a true pressure vessel for resistance to high external pressure. The P10 shelter system is a third generation design and is based on 10 years field experience with McCarthy’s successful TBC6, and ES10 fiberglass underground shelters. The P10 is much easier to enter and exit with its offset entranceway. The hatch at ground level of the P10 is available in several different levels of threat resistance. The geometry of the P10 allows the much-preferred offset entranceway. This has the same radiation geometry shielding as a 90-degree entranceway plus it provides the most efficient escape for moisture and heat. SHELTER CONSTRUCTION


    The P10 Underground Bomb Shelter is an egg-shaped fiberglass structure designed for maximum brightness ​

    The paraboloid shelter and entranceway are made of structural fiber&shy;glass manufactured to The American Society of Testing and Materials, and shelter engineering standards of PRINCIPLES of PROTECTION, U.S. Handbook of NBC Weapon Fundamentals and Shelter Engineering Standards, Fiberglass was chosen as the optimum material because of its extremely high resiliency and corrosion resistance plus its ability to be shaped into a compoundly curved structure. The 40 psi (pounds per square inch) external pressure resistance, with no earth arching, is constant over 100 years and does not have to be de-rated like steel each passing year due to corrosion. Fiberglass also forms a complete vapor barrier which provides a dry atmosphere when placed below ground, and it has proven to be sound in the underground storage tank industries. In addition, one of the greatest characteristics of fiberglass is its ability to "remain intact" if overstressed. The inside of the shelter is smooth, curved, and white to create maximum brightness with minimal light. All of these facilities function without outside electricity through the use of 12-volt, deep-cycle batteries. The inside surface is easily cleaned with common detergents and is easily repaired.


    Opposite the filter pocket on the entranceway is the 45-gallon fiberglass leach&shy;ing septic tank designed into the entranceway. The septic tank has duration of 3-6 months depending on the number of shelterists and diet. It is easily pumped out with an optional manual septic pump from the ground surface by removing the septic tank access port.


    The P10 contains 1337 cubic feet (10,000 gal) with headroom from 6’-8" to 8’-8". This allows for normal living and a very spacious feeling. There is ample light for reading anywhere in the shelter supplied by a 15-watt fluorescent light located on the ceiling of the shower housing. Fresh filtered air is brought into the shelter by a 12-volt 40,000-hour air blower designed to operate 24 hours per day for approximately 30 days and supplies many times the breathing volume of air required by adults. This system has the advantage of maintaining constant shelter temperature, constant shelter oxygen levels, constant shelter carbon dioxide levels, and constant shelter mois&shy;ture levels, plus it prevents overheating which is common with manual air blowers in warm cli&shy;mates. Exhausting of hot, moist, spent air is facilitated through the entranceway which is located on the end of the shelter but very close to the highest point of the ceiling. The hot, moist, spent air rises up through the entranceway to the vent at the top of the entranceway where it exits the shelter through the hatch dome at ground level. This is the most efficient geometry for exhausting spent air, especially when resisting intruder assaults is a critical part of the hatch design. BATTERY POWER

    Sixten 12-volt deep-cycle sealed batteries are stored in a fiberglass battery box under the floor. The normal loss of battery power is approximately 1.5% per month without any charging.

    The P10 Underground Bomb Shelter comes with 16 12-volt batteries ​

    The P10 Underground Bomb Shelter comes with a 115 volt battery charger ​

    A 115 volt battery charger/maintainer and timer is used to keep the batteries charged.

    A photovoltaic panel (solar panel) can also be used to maintain the batteries if desired. A 50-foot battery charg&shy;ing cable can also be connected from the batteries in the shelter to the battery in a car to allow the car alternator to charge the batteries.


    1. Contaminated air enters the air intake hole on the elliptical hatch dome. It then travels around under the hatch dome where the air velocity slows allowing rain and heavy particles to fall out.

    2. Contaminated air then travels into the vertical pipe under the hatch dome and past the ball valve.

    3. The contaminated air then travels into the stainless steel micronic washable screen/pre-filter removing more of the heavier particles.

    The P10 Underground Bomb Shelter comes with a multi-chamber air filtration unit that kills or eliminates ALL nuclear, biological and chemical agents ​

    The P10 Underground Bomb Shelter's gas agent test housing (GATH) uses the M256A chemical agent test kit ​

    4. The air then travels into the Gas Agent Test Housing where the air can be tested using the M256A chemical agent test kit. A 4 inch white pipe plug is removed to insert the test kit.

    HEPA/Filter Sleeve

    5. [​IMG]
    The P10 Underground Bomb Shelter's HEPA filter removes 99.99% of particles that are 0.3 microns and larger ​

    The contaminated air then travels into the core of the HEPA/Carbon filter designed to remove 99.99% of particles that are 0.3 u (microns) and larger. This is where the carriers of biological warfare agents are removed. The photo at left shows the HEPA/Carbon sleeve.

    6. The air then travels into the activated carbon layer to remove the radioactive iodine gas.

    7. The next layer is made of Whetlerite/TEDA carbon to remove any chemical warfare agents. [​IMG]
    The P10 Underground Bomb Shelter's ultraviolet bulb kills all airborne viruses and bacteria ​

    8. The air then passes through a filter fabric to remove any carbon fines.

    9. The last stage of filtration after the filter sleeve is the ultraviolet light chamber were viruses and bacteria are exposed to more than 11,000 microwatts seconds/cm2 killing all airborne viruses and bacteria.

    10. The filtered air then enters the air blower centrifugal reverse curve motorized impellar and into the shelter.

    11. As the air blower pumps filtered air into the shelter, the shelter is slightly pressurized. This positive pressure plus the heat generated in the shelter from body heat, cooking, and showering, forces the spent air to the highest point in shelter near the top of the entranceway.

    12. At the top of the entranceway is the air outlet screen where the spent air passes through and up the air pipe and out of the elliptical hatch dome air outlet hole. Some air will pass through and around the hatch cover base because the hatch cover is not intended to be air-tight.

    13. As the air passes around the underside of the hatch dome is equilibrates with the outside air. This results in little or no thermal signature because there is little difference between the spent air and ambient air.

    The P10 Underground Bomb Shelter's stainless steel air outlet removes carbon dioxide, heat, moisture and odor ​

    Air Outlet

    The spent air containing carbon dioxide, heat, moisture, and odors exits the shelter at the highest point just under the hatch dome. The air outlet housing contains a stainless steel micronic screen to prevent bees and even tiny ants from entering the shelter. The air outlet housing can be closed by inserting a 4 inch diameter plastic pipe plug.

    The P10 Owner’s Manual details specific safe procedures for replacing contaminated HEPA filters. Both air inlet and air outlet have shut-off valves and washable stainless micronic screens accessible from inside the shelter.


    The P10 Underground Bomb Shelter's triple-axis seismic joint eliminates frost line stresses ​

    This triple axis seismic joint allows the entranceway free and independent movement from the main shelter. The entranceway is located within the frost line, while the shelter is well below the frost line. This creates tremendous stresses during winter months when the entranceway is forced up 0.5 - 1.25 inches due to frozen ground. The seismic joint removes these stresses by allowing vertical movement of the entranceway and also allows the top of the entranceway to move laterally to maintain structural integrity during rolling ground motion from severe ground shock. The entranceway can also move in translation or sideways 1 inch.


    There are 37 cubic feet of storage (276 gal.) under the floor. In addition there are 300 cubic feet of storage under the upper deck that allow forty-four – 5-gallon food tanks to fit under the upper deck. A 30-gallon aluminum alcohol tank is used for cooking. The 5 gallon food tanks are used to store grain, powdered milk, salt, sugar, beans, TVP, honey, etc. and hold approximately 2000 lbs. of food, forming a 1 year food supply for five people. The food supply can be extended with the purchase of more food tanks. The material and thickness of these food tanks allows the much preferred carbon dioxide packing of food as opposed to the nitrogen packing of food. The 30-gallon aluminum methanol tank was sized to boil all the water in the 1000-gallon water tank plus all the food in 44 of the 5-gallon food tanks. Storage is more easily managed with the optional Moon Shelves which runs around the perimeter of the shelter and provide an additional 13 ft<SUP>3</SUP>.


    The P10’s 1000 gal fiberglass paraboloid high external pressure tank is located external to the shelter. It is filled on the ground surface by a hose which also serves as the tank vent. The volume of water in the tank is determined by a stainless steel 0-10 psi pressure gage located under the shelter floor. The psi on the gage is used in connection with the graph below.

    The P10 Underground Bomb Shelter's water tank contains 1,000 gallons ​


    Multiple P10’s can be connected together using "T connectors" and seismic joints. This is usually limited to 10 shelters.

    The P10 Underground Bomb Shelters can be connected in a condominium fashion ​


    The P10 Underground Bomb Shelter's hatch dome is impervious to intruders ​

    The P10 Underground Bomb Shelter's hatch dome allows even a 75"+ waist to quickly enter the shelter ​

    The elliptical hatch dome at ground level is aerodynamically smooth. The 24 x 26 -inch manhole allows very large people with a 75-inch+ waist to enter the shelter quickly. The hatch dome contains the recessed hatch cover that slides open and is designed for severe impact of high speed flying debris. The angle of incidence of the hatch dome is only 30 degrees to allow flying debris to glance off. The hatch dome and hatch cover are designed to resist a non-shattering 3-inch diameter hail ball falling straight down at terminal velocity (87 mph) and impacting directly at a full 90-degree angle of incidence. The hatch dome is also designed to resist a non-shattering 3-inch diameter hail ball traveling horizontally at 150 mph. In addition, the hatch dome can resist a solid 2 x 4 wooden stud impacting the hatch dome like a battering ram or javelin at 30 to 350 mph depending on the hatch class. Some debris, depending on the size, shape, angle of incidence, and mass, may cosmetically damage the hatch dome. This can be easily repaired with fiberglass repair kits available at marine and automotive supply stores.

    <TABLE cellSpacing=0 cellPadding=0 border=1><TBODY><TR><TD vAlign=top>Tornado F-Scale</TD><TD vAlign=top>F0</TD><TD vAlign=top>F1</TD><TD vAlign=top>F2</TD><TD vAlign=top>F3</TD><TD vAlign=top>F4</TD><TD vAlign=top>F5</TD></TR><TR><TD vAlign=top>Windspeed (mph) </TD><TD vAlign=top>40-72</TD><TD vAlign=top>73-112</TD><TD vAlign=top>113-157</TD><TD vAlign=top>158-206</TD><TD vAlign=top>207-260</TD><TD vAlign=top>261-318</TD></TR></TBODY></TABLE>

    The hatch dome is made of a material called "Combat Composite<SUP>TM</SUP>" which is a structural fire-and bullet-resistant laminate developed by Radius Engineering Inc. The hatch dome is also designed to protect the shelter from a fire reaching 1700<SUP>o</SUP>F for one hour while maintaining its structural integrity in compliance to ASTM E119. This design and material makes the P10 very stealthy. It produces little or no thermal signature, little or no metallic signature, and little or no radar signature. When the shelter is installed, all that can be seen is the dark army-green hatch dome at ground level. This makes it almost impossible to be detected by modern target acquisition equipment. It is designed to resist 350-mph winds and more than 8.5 on the Richter Scale. Although the hatch dome is not impenetrable, it is specifically de&shy;signed to resist seven basic assaults from people trying to break into the shelter in compliance to P.O.P.

    The hatch dome and hatch cover are manufactured according to The National Institute of Justice NIJ standards from Class 0 (standard on P10) up to Class IV to resist penetration by various threats. The material and thickness vary as the threat level increases. The classes listed below are based on resisting 90% of all of the bullet types at various velocities listed known as (V-90). The barrel length, feet per second (fps) or meters per second (mps) for the test are noted.

    <TABLE cellSpacing=0 cellPadding=0 border=1><TBODY><TR><TD vAlign=top>NIJ


    </TD><TD vAlign=top>Hatch Material

    </TD><TD vAlign=top>Threat/Bullet Type</TD><TD vAlign=top>Barrel


    </TD><TD vAlign=top>fps</TD><TD vAlign=top>mps</TD></TR><TR><TD vAlign=top>Class 0</TD><TD vAlign=top>Structural Fiberglass-self-extinguishing (standard)</TD><TD vAlign=top>Light Hammer and hatchet assaults, 3 in. dia. Hail @ 87-mph vertical, 150-mph horizontal

    2 x 4 stud @ 30-mph
    </TD><TD vAlign=top>NA</TD><TD vAlign=top>NA</TD><TD vAlign=top>NA</TD></TR><TR><TD vAlign=top>Class I</TD><TD vAlign=top>Combat Composite


    </TD><TD vAlign=top>.22 Cal. 40 Gr. LR

    .25 Cal Auto 71 Gr. FMJ

    .32 Cal. Auto 71 Gr. FMJ

    .380 Cal. Auto 88 Gr. JHP

    .38 Cal Special Lead 158 Gr. RN

    .38 Cal Special 158 Gr. SWC

    2 x 4 stud @ 70-mph
    </TD><TD vAlign=top>6






    </TD><TD vAlign=top>1050





    </TD><TD vAlign=top>320





    </TD></TR><TR><TD vAlign=top>Class II</TD><TD vAlign=top>Combat Composite


    </TD><TD vAlign=top>.41 Mag. 210 Gr. JSP

    .44 Mag. 240 Gr. JSP

    .44 Mag. 240 Gr. Lead SWC

    .357 Mag. 125 Gr. JHP

    .357 Mag. 110 Gr. JHP

    .357 Mag. 158 Gr. JSP

    .357 Mag. 158 Gr. Hornady

    19mm 175 Gr. Silvertip

    9mm 124 Gr. FMJ

    9mm 115 Gr. Silvertip

    2 x4 stud @ 100-mph
    </TD><TD vAlign=top>4










    </TD><TD vAlign=top>1300









    </TD><TD vAlign=top>397









    </TD></TR><TR><TD vAlign=top>Class III

    </TD><TD vAlign=top>Combat Composite

    </TD><TD vAlign=top>7.62 NATO Ball 150 Gr. M-80 steel Jack

    7.62 NATO Ball 150 Gr. m-80 FMJ

    30.06 PSP 180 Gr.

    .30 Carbine 110 Gr. FMJ

    12-Gauge Rifled Slug

    .223 (5.56mm) 55 Gr. FMC

    7.62 x 39 Ball

    2 x4 stud @ 200-mph
    </TD><TD vAlign=top>28









    </TD><TD vAlign=top>2750






    </TD><TD vAlign=top>838






    </TD></TR><TR><TD vAlign=top>Class IV</TD><TD vAlign=top>Combat Composite


    </TD><TD vAlign=top>30.06 A.P. M-2

    7.62 mm NATO A.P. 308 Win

    SS 109 FN NATO .223 (5.56mm)

    7.62 x 39 Russian/Chinese A.P.I.

    2 x4 stud @ 350-mph
    </TD><TD vAlign=top>26




    </TD><TD vAlign=top>2850



    </TD><TD vAlign=top>868




    Hatch Cover interior and Exterior Lock

    The P10 hatch slides open and closed hydraulically powered by a 12 volt hydraulic power unit located on the moon shelf in the shelter. The hatch slides and locks wherever it stops. The remote radio controlled transmitter has a button to slide the hatch closed and open. When inside the shelter, the hatch can be closed by standing on the floor and activating the transmitter. This allows submarine type entry without human power to move the 200 lb hatch cover. The hatch cover is recessed in the hatch dome and protected from flying debris for 320 degrees. The hatch cover is designed to resist 5300 lbs. of uplifting force caused by the negative pressure of a tornado or explosion and 42,080 lbs of overpressure. The average time it takes for untrained or inexperienced people to enter the shelter is approximately 8-10 seconds per person.


    The P10 is not impenetrable but is difficult to break into while shelterists are inside. <TABLE cellSpacing=0 cellPadding=0 border=1><TBODY><TR><TD vAlign=top>INTRUDER ASSAULT

    </TD><TD vAlign=top>P10 RESISTANCE

    </TD></TR><TR><TD vAlign=top>1. Intruder trying to break into hatch using sledgehammer, hatchets, and guns. </TD><TD vAlign=top>Class 0 Hatch resists light hammer and hatchet assaults

    Class I -IV Hatch resists all assaults
    </TD></TR><TR><TD vAlign=top>2. Intruder trying to clog the air intake/outlet to suffocate the shelterists thus forcing them outside.</TD><TD vAlign=top>Shelterists can open up hatch and reach over to unclog air intake or wait in safety in the shelter for many hours in sealed shelter atmosphere while the intruder is exposed to the outside danger. </TD></TR><TR><TD vAlign=top>3. Intruder trying to suffocate shelterists by creating fire on top of the hatch thus forcing the shelterists outside.</TD><TD vAlign=top>All classes of the hatch are resistant to fire and the shelterists can breath normally inside the shelter based on sealed shelter atmosphere.</TD></TR><TR><TD vAlign=top>4. An intruder trying to run over the shelter or hatch with an automobile or truck. </TD><TD vAlign=top>If this vehicle becomes a threat, the Emergency Acme Jack rod can be used. </TD></TR><TR><TD vAlign=top>5. An intruder trying to drown shelterists by forcing water into the air inlet/out. </TD><TD vAlign=top>The air inlet on the hatch dome are baffled to prevent this type of assault. </TD></TR><TR><TD vAlign=top>6. An intruder trying to attach rope onto the hatch or air manifolds to damage or pull out of ground.</TD><TD vAlign=top>The hatch dome is a smooth design with no projections to easily attach to.</TD></TR><TR><TD vAlign=top>7. An intruder using a cutting torch to cut the hatch open. </TD><TD vAlign=top>The hatch is impervious to a cutting torch. </TD></TR><TR><TD vAlign=top>All attacks above</TD><TD vAlign=top>Release of tear gas through hatch. Details are reviewed in Owner’s Manual. </TD></TR></TBODY></TABLE>SEALED SHELTER ATMOSPHERE

    The P10 Underground Bomb Shelter's air blower should be turned off if there are fires right at the hatch. ​

    When ground fires are present around the hatch, the air blower should not be turned on to bring in fresh air. During this time, the shelterists must breathe in a sealed shelter atmosphere. The safe duration time is based on a 3% carbon dioxide limit. The time it takes for the shelter atmosphere to reach this limit is a function of the number of shelterists, degree of physical activity of the shelterists, and the volume of the shelter above the floor. This duration is shown below for adults performing mild work.


    The P10 Underground Bomb Shelter uses simple yet powerful air pressurization techniques ​

    The P10 does not use blast valves. Instead, it uses the "overpressure choking" which has no moving parts. The inlet air valve and outlet air valve are sized to prevent excessive pressure from developing inside the shelter. This is a combination of what is known as the Ideal Gas Law combined with Bernoulli's Law. These two theories combined state that two volumes of air (outside air volume and shelter air volume) with differing pressure will reach equilibrium or "equilibrate" over a period of time. This period of time depends on the level of overpressure, volume of the shelter, diameter and length of the air inlet and outlet pipe, resistance of air filter, and duration of the overpressure which is very short and constantly decreasing. Simply stated; the air inlet and outlet are sized so that there is not enough time for the two volumes of air to equilibrate. The outside pressure at maximum duration is simply not able to equilibrate through a 3-inch diameter air inlet and outlet within the overpressure duration.


    The P10 Underground Bomb Shelter's plumbing system includes a toilet, sink and shower ​

    The water supply system is based on a 12-volt high pressure automatically regulated water pump and stainless steel pressure tank to maintain system pressure. The pump produces enough pressure to force the water through the 0.3 micron absolute ceramic water filter and supplies approximately 0.5 gallons per minute at the sink faucet and shower head in the bathroom. Two of the fourteen batteries will supply enough power to pump 1000 gallons of filtered water to the shelter. The fiberglass counter contains a stainless steel sink where dishes and clothes are washed. The sink drains into a 2-gallon gray water tank to supply flushing water to the toilet.

    Fittings- The shelter entranceway contains two ¾ inch NPTF thru-hull couplings five feet below ground level, for connection to the water tank and five ¾ inch NPTF threaded outlets one foot below ground level for bring&shy;ing in antenna lines, a phone line, a power sup&shy;ply, and a 12-volt power cable from a solar panel to recharge the batteries. With the optional communications package there are two additional 1-inch diameter NPTF fittings located in the hatch dome so HAM and Scanner antennas can be installed. Plugs are provided to be in place when antennas are not in place.

    Toilet- The flush-up toilet is powered by a manual hand pump and uses water from the gray water tank. The sewage is pumped up to the leaching septic tank through an internal hose.

    Shower- The fiberglass bathroom floor allows all water from the shower head to drain into the shower gray water tank which is transferred to the sink using a manual foot pump. The gray water is used to flush the toilet. Chemical or nuclear decontamination is per&shy;formed in this shower.


    Radiation shielding from overhead in the P10 is provided by 8 feet of earth at the crown of the shelter ceil&shy;ing. With a TRS (Total Rems in Shelter at the bed area) of 1 rem at 20 psi, a person would receive a maximum acute radiation dose from overhead and through the entranceway for neutron and gamma radiation equivalent to 1 mammography x-ray. This dose is based on a 500 KT air burst nuclear weapon, which produces a higher neutron radiation dose than the larger MT weapons, plus fallout doses from a 1 MT surface burst nuclear weapon to maximize the fallout gamma radiation dose.

    Based on the worst cancer cases (leukemia) from the Hiroshima and Nagasaki victims, a 10-rem dose may increase the cancer rates from the cur&shy;rent rate of 352/100,000 up to 355/100,000. It should be kept in mind that the Hiroshima victims were totally unprepared and uneducated. They were malnourished and already suffering from many diseases during a critical wartime period where food, medical supplies, and other necessi&shy;ties were in short supply. In addition, they were not only exposed to heavy, acute external radia&shy;tion doses but also internal radiation doses from eating contaminated food and inhaling radioactive fallout. Educated shelterists can avoid such damaging effects and can determine the radiation levels with a simple radiation survey meter.

    The P10 Underground Bomb Shelter Neutron Radiation Shielding ​

    The P10 Underground Bomb Shelter's Gamma Radiation Shielding ​


    The P10 can provide life support in severe nuclear, biological and chemical warfare environments with the optional NBC Package. This package contains the MCAS filtration system, to remove particulates including carriers of biological agents. The HEPA filter is designed for 60 cfm with 99.99% efficiency @ 0.3 u (microns). A Gas Agent Test Housing allows testing of chemical agents from inside the shelter using the M256A chemical agent test kit. The next stage of filtration is a carbon canister filter containing activated carbon (to remove radioactive iodine gas) and Whetlerite carbon (to remove chemical warfare agents). A radiation survey meter is also included in this package. The last stage of filtration is germicidal radiation to kill viruses, bacteria, and molds. ALCOHOL TANK

    The P10 Underground Bomb Shelter's 30-gallon methanol tank can boil all of the shelter's 1,000 gallons of water, as well as the water from forty-four 5-gallon food tanks ​

    The 30-gallon methanol tank was sized to boil all the water in the 1000-gallon water tank plus all the food in 44 5-gallon food tanks.

    Emergency Escape

    In the event that heavy debris falls on the hatch cover and the radios are not able to bring help to clear the hatch, and the debris can not be burned off, emergency escape procedures can be implemented. The P10 uses a battery operated or a hand operated hydraulic pump to power a hydraulic cylinder to force the sliding hatch open. The force required to produce a given amount of pressure using the hand pump is shown in the graph below.

    The P10 Underground Bomb Shelter uses a sliding hatch system for emergency escapes ​


    The P10 Underground Bomb Shelter is delivered from our factory in Forney TX ​

    U.S. citizens have a legal right to install a shelter. Under the second amendment of the United States Constitution, U.S. citizens are guaranteed the right to bear arms to provide protection in life threaten&shy;ing situations. Tornadoes, earthquakes, nuclear, biological, and chemical warfare fall under this amendment as life threatening forces. A disaster shelter falls under this classification as a defensive arm.


    The customer hires a contractor to dig a hole (approximately 200 yards) with a base dimension of 24 feet x 12 feet at a depth of 18 feet. The top of the hole should be larger to allow for sloped walls. The excavation usually requires less than one day. A 40,000 pound excavator or larger should be used to dig the hole and lift the P10 off of the Radius truck and into the hole. If the shelter is installed in a flood zone, the shelter should be installed by berming so the hatch is one foot above the 100-year flood plain or storm surge. Berming can also be used if the shelter is installed in a location which has ledge.

    The P10 Underground Bomb Shelter will be invisible after installation ​


    1) The shelter is lifted off of the truck and into the hole by the excavator where it is leveled at the proper height at the bottom of the hole.

    2) The entranceway is lifted on to the shelter and connected using 24- ½ in bolts.

    3) The shelter is then backfilled with 140 yards of ¾ minus crushed stone, pea stone, or sand. After this stage, the surrounding soil can be used for backfill and must be compact&shy;ed evenly around the shelter.

    4) The water tank is lifted into the hole next to the entranceway and the 3/4- inch diameter hose is connected to the shelter.

    5)When the backfill height reaches the shelter septic tank, 1.5 cubic yard of crushed stone or pea stone for the leaching field should be placed around the septic tank and water fill/vent pipe.

    6) When the backfilling reaches 12 inches below ground level, all the antenna cables, telephone lines, 12 volt lines etc. are connected.

    7) Backfill&shy;ing continues to the original ground level. Back&shy;filling usually requires approximately 10 hours.

    Home Made Shelter vs. Commercial Shelters

    Advantages of purchasing a commercial underground shelter:

    1) With shelters built on site, cost overruns are the rule, not the exception. Many well-intended handymen and contractors have constructed shelters which ended up running well over budget and still did not produce an operable shelter. When a shelter is built on site, you really don’t know what you will end up with. The P10 shelter allows people to deal with known costs and a proven shelter system.

    2) Shelters built on site require extensive, time consum&shy;ing, and expensive research to develop a "shelter sys&shy;tem" capable of providing dependable life support—fresh filtered air, blast protection, clean water, light, corrosion resistance, toilet facilities, air filtration for radioactive fallout, chemical and biological agents, etc., all of which should meet PRINCIPLES of PROTECTION, by Walton McCarthy, is available for $65.00 from The American Civil Defense Association, (TACDA) Starke, FL (800-425-5397). Even good architects or mechanical and civil engineers, do not have the expertise to develop a good dependable shelter system especially when it must function without local electricity. The P10 shelter system is based on the ES10 and P10 shelter, which has over 20 years proven field experience and complies with all P.O.P. standards.

    3) Concrete shelters built on site are not able to be excavated and re-installed at another location and they are very hard to make waterproof, especially under the floor. The shortcomings of steel underground storage tanks are:

    a) They may require registration because its intended use is for storage of petroleum and/or chemi&shy;cal products.

    b) A horizontal cylinder is a poor structural shape because it behaves as flexible conduit.

    c) It must also be cathodically protected or fiberglass coated.

    d) Steel underground structures suffer from condensation on the inside walls. The P10 is designed strictly as a shelter and can be excavated and re-installed at some other location if desired.

    4) Shelters built on site require a building permit and confirmation by a local professional engineer because it involves actual construction, including a septic design. The P10 is a commercially available, professionally engineered disaster shelter with a formal Owner’s Manual reviewing all operations. If require, it is much easier to secure a building permit for installing the P10 shelter than it is for constructing a shelter on site.

    5) Shelters built on site often require many days or weeks to complete construction. During this time, children are exposed to the danger of falling in the hole and curiosity seekers are afforded ample time to see what is being constructed. The P10 can be installed in one day.

    6) Shelters built on site have no established market value. The P10 has a known commercial value which allows financing.

    Large shelters built on site to protect many people present the following problems:

    a) A separate piece of land must be agreed on by the shelterists and pur&shy;chased. This piece of land may have to be commercially zoned. Local land may not be available; also, a caretaker may have to be appointed.

    b) A professional engineer and architect must be consulted for the design.

    c) A commercial building and septic permit must be issued. Even a single-family shelter is difficult to con&shy;struct unnoticed. This is rather difficult because the building code requirements do not apply to under&shy;ground structures designed for disaster environments. The technology for modern shelters is very different than that of standard building structures.

    d) Under&shy;ground and above-ground storage tanks designed to contain fuel and water must be registered and approved by local and federal environmental protection agencies (EPA).

    e) Notification to the local fire department of the exact location of all fuel tanks must be made.

    f) Financ&shy;ing such a structure by a local bank is impossible be&shy;cause it has no resale value due to its custom nature.

    g) To make matters more complicated, the applications for all the above permits are a matter of public record. The only solution in the United States is to install a commercially available underground shelter.

    Radius Engineering Inc. Warranties that the fiberglass parts of the P10 Disaster Shelter will not leak, corrode, or structurally fail for a period of 10 years provided that 1) the shelter is not exposed to excessive overpressure, 2) The structural parts of the shelter are not modified. 3) The shelter is inspected, off-loaded, assembled, backfilled and installed in accordance with the company’s installation instructions. The warranty does not apply to the parts and equipment that Radius Engineering Inc. does not manufacture. These items are covered by the individual manufacturers. Radius Engineering Inc. is continuously improving its product and therefore reserves the right to change any specification without notice. Our liability under this warranty shall be limited to, at our option, repair of the shelter, or delivery of a replacement shelter to the point of original delivery, or refund of the original purchase price. We shall not be liable for any indirect or consequential damages, labor, or installation costs. P10 TECHNICAL DATA

    <TABLE><TBODY><TR><TD>1 MT AIR/SURFACE BURST *Notes</TD><TD>Units</TD><TD>20 psi</TD><TD>40 psi</TD><TD>60 psi</TD></TR><TR><TD colSpan=15><HR></TD></TR><TR><TD>Distance From Ground Zero</TD><TD>~1 miles</TD><TD>1.4</TD><TD>0.85</TD><TD>0.7</TD></TR><TR><TD>Radiation Dose-Neutron</TD><TD>~2 rems</TD><TD>9000</TD><TD>60000</TD><TD>160000</TD></TR><TR><TD>Radiation Dose-Initial Gamma</TD><TD>~3 rems</TD><TD>3250</TD><TD>20750</TD><TD>45000</TD></TR><TR><TD>Radiation Dose-Fallout Gamma</TD><TD>~4 rems</TD><TD>12000</TD><TD>12000</TD><TD>12000</TD><TD></TD></TR><TR><TD>Overhead Dose-Neutron</TD><TD>~5 rems</TD><TD><1</TD><TD><1</TD><TD><1</TD></TR><TR><TD>Overhead Dose-Gamma ~6 rems</TD><TD><1</TD><TD><1</TD><TD><1</TD></TR><TR><TD>Radiation Dose-HEPA ~7 rems</TD><TD>0</TD><TD>0</TD><TD>0</TD></TR><TR><TD>Entranceway Gamma+Neutron -ctr</TD><TD>~8 rems</TD><TD>2</TD><TD>10</TD><TD>26</TD></TR><TR><TD>Total Rems In Shelter- ctr</TD><TD>~9 rems</TD><TD>7-20</TD><TD>34-40</TD><TD>88-60</TD></TR><TR><TD>Total Rems In Shelter-bed area</TD><TD>~10 rems</TD><TD>2-20</TD><TD>8-40</TD><TD>22-60</TD></TR><TR><TD>Shelter Internal Pressure</TD><TD>~11 psi</TD><TD>0.8</TD><TD>1.5</TD><TD>2.0</TD></TR><TR><TD>Displacement-Horizontal ~13 inches</TD><TD>0.57</TD><TD>1.25</TD><TD>1.41</TD></TR><TR><TD>Seismic Equivalent</TD><TD>~14 Richter</TD><TD>8.5</TD><TD>8.5+</TD><TD>8.5+</TD></TR><TR><TD>Probability Of No Excessive OP</TD><TD>~15 %</TD><TD>96.2</TD><TD>96.8</TD><TD>97.1</TD></TR></TBODY></TABLE>P10 SPECIFICATIONS

    <TABLE><TBODY><TR><TD>Air blower life..</TD><TD>60,000 hours</TD></TR><TR><TD>Air blower type..</TD><TD>8-in dia. Reverse curve centrifugal 12-V, 7.5 watt</TD></TR><TR><TD>Air blower volume..</TD><TD>40-60 cfm @ 1 in S.P.</TD></TR><TR><TD>Air filter..</TD><TD>HEPA 99.99% @ .3 u</TD></TR><TR><TD>Air filter-carbon-activated residence time..</TD><TD>0.4 sec</TD></TR><TR><TD>Air filter-carbon-whetlerite residence time..</TD><TD>0.4 sec</TD></TR><TR><TD>Air manifold..</TD><TD>elliptical ring/ baffle</TD></TR><TR><TD>Antenna Fittings..</TD><TD>2 in and 1 inch NPTF accessible internally</TD></TR><TR><TD>Assembly time..</TD><TD>2 man-hours</TD></TR><TR><TD>Backfill material required..</TD><TD>gravel or ¾- in. crushed stone (140 16*16= yards)</TD></TR><TR><TD>Batteries..</TD><TD>16- 115 amp hour deep cycle marine</TD></TR><TR><TD>Capacity-adults..</TD><TD>10</TD></TR><TR><TD>Connector port to other shelters..</TD><TD>36-inch diameter with cap</TD></TR><TR><TD>Duration-blower + light 24hr/day – 6 adults..</TD><TD>30 days</TD></TR><TR><TD>Emergency escape ..</TD><TD>hydraulic cylinder 10,000 lb force@2500 psi</TD></TR><TR><TD>Entranceway diameter..</TD><TD>36 inch</TD></TR><TR><TD>Excavated hole size..</TD><TD>12 ft. x 24 ft. x 18 ft. deep (200+ yds)</TD></TR><TR><TD>Fire resistance..</TD><TD>ASTM E-119 1 hr @ 1700 F. mechanical</TD></TR><TR><TD>Name Floor Type Center Beam..</TD><TD>pinned one end, floating opposite end</TD></TR><TR><TD>Floor material..</TD><TD>5/4 cedar/cypress planks</TD></TR><TR><TD>Floor space..</TD><TD>100 ft<SUP>2</SUP></TD></TR><TR><TD>Gravity-earth..</TD><TD>105,000 lbs.</TD></TR><TR><TD>Hatch cover..</TD><TD>28 x 34 in </TD></TR><TR><TD>Hatch dome –angle of incidence..</TD><TD>30 degrees </TD></TR><TR><TD>Hatch dome material..</TD><TD>Combat Composite-by Radius Eng. Inc.</TD></TR><TR><TD>Hatch exterior lock..</TD><TD>remote transmitter</TD></TR><TR><TD>Hatch interior latch..</TD><TD>remote transmitter</TD></TR><TR><TD>Hatch manhole ..</TD><TD>24 x 26 inch</TD></TR><TR><TD>Hatch pressure resistance..</TD><TD>40 psi positive, 5 psi negative </TD></TR><TR><TD>Head room..</TD><TD>6’-8" to 8’-8"</TD></TR><TR><TD>Hull material..</TD><TD>structural fiberglass</TD></TR><TR><TD>HEPA Filter..</TD><TD>60 cfm, 99.99% @ 0.3u</TD></TR><TR><TD>Hydrostatic pressure (buoyancy)..</TD><TD>84,937 lbs.</TD></TR><TR><TD>Implosion type..</TD><TD>non-catastrophic</TD></TR><TR><TD>Installation time..</TD><TD>1 day</TD></TR><TR><TD>Interior color..</TD><TD>white, flame spread of 25-50 Type II, ASTM E84</TD></TR><TR><TD>Ladder..</TD><TD>5052 Aluminum</TD></TR><TR><TD>Lighting..</TD><TD>12-volt 15watt florescent 870 lumens</TD></TR><TR><TD>Max .wind..</TD><TD>150 -350 mph class 0-IV</TD></TR><TR><TD>Overpressure – allowable..</TD><TD>40 psi with no earth-arching effect</TD></TR><TR><TD>Sealed shelter atmosphere- 10 adults..</TD><TD>5 hours</TD></TR><TR><TD>Septic Tank..</TD><TD>45 gallon external fiberglass</TD></TR><TR><TD>Shape..</TD><TD>paraboloid 1:2 elliptical ratio</TD></TR><TR><TD>Shipping weight..</TD><TD>11,000 lbs.</TD></TR><TR><TD>Storage volume-under floor..</TD><TD>37 ft<SUP>3 </SUP>(1000 gal.)</TD></TR><TR><TD>Storage volume-under upper deck..</TD><TD>64 ft<SUP>3</SUP> </TD></TR><TR><TD>Thru hull couplings..</TD><TD>4- ¾- inch NPTF standard</TD></TR><TR><TD>Thru hull hookups..</TD><TD>outside 110-volt, antenna cables, solar, etc.</TD></TR><TR><TD>Ultraviolet Exposure..</TD><TD>11,200 microwattsec/cm<SUP>2</SUP></TD></TR><TR><TD>Volume-Total..</TD><TD>1337 ft<SUP>3 </SUP>(10,000 gal.)</TD></TR><TR><TD>Water table allowable height..</TD><TD>full water table to ground surface</TD></TR><TR><TD>Water Tank Gage..</TD><TD>stainless 0-10 psi – see graph</TD></TR><TR><TD>Water Tank..</TD><TD>500/1000 Gal external fiberglass</TD></TR></TBODY></TABLE>

  2. TnAndy

    TnAndy Senior Member Founding Member

    Wow Melbo...that's a LOT of good info.....

    1 question.....are pork&beans allowed ? .....I keep picturing "a fart in a space suit" as I looked at it.....ahahahahaaaa
  3. melbo

    melbo Hunter Gatherer Administrator Founding Member


    There is one in the ground and for sale in Tellico for around $25K
    Want to go halvsies?

    I was supposed to go look at it today but it may have to wait til Monday.

    Lemme go find the installation instructions... I bet we could knock it out in a weekend.

  4. E.L.

    E.L. Moderator of Lead Moderator Emeritus Founding Member

    Very interesting. Forney is only about an hour away from me. I might have to plan a trip over.
  5. JC Refuge

    JC Refuge Emergency Essentials Store Vendor

    The Radius shelters are certainly appealing from an aesthetic design standpoint, but if you are serious about putting in a livable shelter for a number of people, you'll quickly come to the conclusion that the paraboloid structure does not allow for much living space at all, and its MSRP prices are way over the top compared to superior competitive shelters that can be built to the customer's size and specs. Yep, I'm talking about our prefab steel shelters.

    For comparison--at close to the same price (the $90,000+ new price for the Radius unit), our builder is right now installing a 900 square foot custom NBC shelter under a new-construction 8000 square foot house. This shelter has elevators, spiral staircase, 13-foot ceilings, and on and on. But of course, a shelter of that size and cost is unusual. Most of our shelters installed in the USA are in the $15K to $30K range (say about 100-200 square feet) and they include such things as the best Swiss NBC positive air pressure filtration systems and impervious blast doors (choice of hatch/ladder entry or door/stairs) out there.

    The value and safety factor you get with our steel shelters always wins the customer over when they do their research. :)

    Our new site, still in need of a few tweaks ... www.safecastle.com
  6. melbo

    melbo Hunter Gatherer Administrator Founding Member

    Thanks JC.

    Can you post some pictures of some of your stuff?
    I'm getting pretty serious about this and am trying to decide whether I should build my own or contract with someone else.

    Some interior shots would be very helpful.
  7. E.L.

    E.L. Moderator of Lead Moderator Emeritus Founding Member

    JC, I would really like to see more pics of the shelters on your web site. Pics sell. What the shelter looks like inside, storage areas, sleeping areas, shower, exhaust, etc. I would also like to see what it looks like installed from the outside, etc. Plus knowing cost for the units ahead of time would help and save time while deciding.
  8. JC Refuge

    JC Refuge Emergency Essentials Store Vendor


    Here's an initial post in my blog from last year in which I revealed my own shelter to the world, in the interest of selling them, of course.

    There were four posts in the series, with photos taken in the last few. (The links to the follow-on posts are at the end of that first post linked above.)

    Melbo, I'm going to PM you another link with more info.
  9. E.L.

    E.L. Moderator of Lead Moderator Emeritus Founding Member

    Thanks for sharing the pics, I am impressed.
  10. TailorMadeHell

    TailorMadeHell Lurking Shadow Creature

    Okay, can someone answer this for me? If I own a 30 acre place out in the country and want to install a shelter, do I have to worry about construction laws like people do in the city? I am thinking that if this is the case, then even though you 'hide' your shelter, there are those that would know of its existence and either try to call it theirs or the local enforcement would step in and try to use it for the relief of the city.

    And I would definitely have to dodge around any underground tank laws. What's the sense in letting everyone know you have fuel buried? Sheesh.
  11. JC Refuge

    JC Refuge Emergency Essentials Store Vendor


    I see you are in California. If there is one state in the union with some quirky local zoning and permit regulations, it is there. That said, CA is one of our busiest and most active areas for our shelter installations. Honestly, if you are rural, chances are pretty good you can either install your shelter undetected, OR you can do it with the necessary permit, and have no problem. As with any kind of construction project, that's a choice a homeowner must make--take out the permit or don't.

    It's VERY rare (maybe twice out of almost 500 shelter installations) when our builder has ever been prevented from installing a shelter. Our shelters are designed and certified by a state certified structural engineer (certified in every one of the lower 48) and meet or exceed FEMA shelter standards in every respect. So it's very rare when a local building inspector is going to pretend that he knows better than those whose backing we have. (We have done dozens of shelters for FEMA projects all over the country.)

    Another part of your question seems to get at another concern customers sometimes have--whether the fact that there is record of your having a shelter will cause you some sort of risk or vulnerability to the authorities commandeering your place and preps for themselves or others.

    We could talk back and forth about that for a long time, but personally I give that NO worry whatsoever ... and if it was a concern--if you're in your shelter and it is secure, then you're safe.
  12. TailorMadeHell

    TailorMadeHell Lurking Shadow Creature

    Good information JC. I will definitely have to look into it. Though I will say that I do not think that I will be trying to get one built here in CA. Too many friggin' earthquakes for my taste. :D I am doing some 'future planning' and the possibilities include Texas, Oklahoma, Alabama, Kansas and northern Louisiana. I do not know to which I may be motivating to. As soon as I know I can better scope out my priorities. Though 'secretive' being one of the biggest. I will look into many ideas as far as that is concerned.

    I follow the 'Plan for the worst, hope for the best' strategy. I would have everything that I needed, doubled for backup contingencies. Example would be double air filtration systems and exhaust portals. I know it will be a tad expensive though when it comes down to it, isn't your safety worth it? Haha.
  13. melbo

    melbo Hunter Gatherer Administrator Founding Member

    I'm just have it done quickly and tell no one.
    In a rural area, should be easy to do
  14. TailorMadeHell

    TailorMadeHell Lurking Shadow Creature

    Sounds like a plan. Do it fast and keep it quiet. That's what I will eventually do even if I have to do it at night. That's what they make big lights for and in the country when there isn't a soul around, it adds benefit. That's my thought anyways.
  15. RightHand

    RightHand Been There, Done That RIP 4/15/21 Moderator Moderator Emeritus Founding Member

    Good information to be had in this thread. Some of our newer members might have missed this
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