Shielding

Q: What’s Required for Nuclear Sheltering?

A: For locations in or close to probable targets, then protection from blast, fire and fallout would be required. For all other areas, more than 95% of the country, then only fallout need be of concern. Blast and fire protection require hardened, usually below ground structures, but even simple expedient backyard earthen shelters providing 15 psi integrity are survivable as close as 2 miles from a 1 MT surface blast. These home built and also prefab ready-to-bury blast shelters, that would survive the blast even closer to ground zero, are detailed later below.

http://www.radshelters4u.com/index3.htm#a2

Blast tests have indicated that the SmallPole Shelter (the most blast-resistant of the earth-covered expedient shelters described in Appendix A) should enable its occupants to survive up to the 50-psi overpressure range – if built with the blast-resistant and radiation- protective features described in following sections, and if located outside an urban area. Calculations show that this earth-covered expedient blast shelter also would give adequate protection at the 50-psi blast overpressure range against the intense initial nuclear radiation that is emitted from the fireball of a 1-megaton explosion.

http://www.oism.org/nwss/s73p939.htm

http://www.cercidas.com/Nukes/ProtectAndSurvive/protect_and_survive.htm

Ready-To-Bury Blast & Fallout Shelters – Inexpensive: This is the pre-built ready-to-bury completed Mini Blast & Fallout Shelter designed by the Oregon Institute of Science and Medicine listed above with the link to the free instructions for doing it yourself.

http://www.radshelters4u.com/index3.htm#a2

It’s small and cramped with only a 4′ diameter by 12′ long, but for many locations it’ll be endurable enough for those most dangerous high levels of fallout radiation in the first 24 hours.

http://www.radshelters4u.com/index3.htm#a2

Ready-To-Bury Blast & Fallout Shelters – Premier, Expensive: High quality state-of-the-art, but very expensive, shelters are available from Radius Engineering. They are paraboloid shelters constructed of structural fiberglass manufactured to underground storage tank standards. Numerous different models available and the nuclear blast/fallout capable units start at $35,000 before accessories. Options include state-of-the-art chem/bio/nuke filter ventilation, water, sanitation, lighting and other support systems to fully outfit it for long term use.

http://www.radshelters4u.com/index3.htm#a2

Adding mass on the floor above your chosen basement corner, and outside against the walls opposite your shelter, can dramatically increase your shielding protection. Every inch thicker adds up to more effective life-saving radiation shielding.

http://www.radshelters4u.com/index3.htm#a2

Ironic FEMA publication

FEMA Shelter Plans: For over 40 years the U.S. Federal Government has produced volumes of information and plans on fallout shelters and related topics. Some of the best material dates back to the sixties days of Duck & Cover drills. The single best collection anywhere of these documents and plans, and much more, can be found at Civil Defense Now!.

http://www.radshelters4u.com/index3.htm#a2

If you have a basement in your home, or at a nearby relatives’ or friends’ house that you can use, your best option is probably to fortify and use it, unless you have ready access to a better/deeper structure nearby.

http://www.radshelters4u.com/index3.htm#a2

For an expedient last-minute basement shelter, push a heavy table that you can get under into the corner that has the soil highest on the outside. The ground level outside ideally needs to be above the top of the inside shelter. If no heavy table is available, you can take internal doors off their hinges and lay them on supports to create your ‘table’. Then pile any available mass on and around it such as books, wood, cordwood, bricks, sandbags, heavy furniture, full file cabinets, full water containers, your food stocks, and boxes and pillow cases full of anything heavy, like earth. Everything you could pile up and around it has mass that will help absorb and stop more radiation from penetrating inside – the heavier the better. However, be sure to reinforce your table and supports so you do not overload it and risk collapse.

http://www.radshelters4u.com/index3.htm#a2

Home Expedient & Effective Sheltering Options You Could Do Very Quickly…

While a fallout shelter can be built anywhere, you need to see what your best options are at home or nearby locally. You want to maximize both the distance from where the fallout will likely be settling and the shielding material (mass) you already have there that could readily be incorporated to better surround and shield your fallout shelter.

Some structures already provide significant shielding or partial shielding that can be enhanced for adequate protection. If you do not have a basement available, you can still use the techniques shown below in any above ground structure, but you’ll need to use more mass to achieve the same level of shielding. You may consider using other solid structures nearby, especially those with below ground spaces, such as commercial buildings, schools, churches, below ground parking garages, large and long culverts, tunnels, etc.. Some of these may require permissions and/or the acquiring of additional materials to minimize any fallout drifting or blowing into them, if open ended. Buildings with a half-dozen or more floors, where there is not a concern of blast damage, may provide good radiation protection in the center of the middle floors. This is because of both the distance and the shielding the multiple floors provide from the fallout on the ground and roof.

Bottom Line: choose a structure nearby with both the greatest mass and distance already in place between the outside, where the fallout would settle, and the shelter inside.

http://www.radshelters4u.com/index3.htm#a2

Regardless of how intense the radioactive fallout is in your specific area, the protective effectiveness of your shelter will be largely based upon its shielding from gamma radiation, the most penetrating and destructive radiation you’ll have to contend with. (And, to a lessor degree on any distance you can put between the fallout deposition and yourself.) Just as body armor protects a person from bullets, so too does mass between you and the fallout protect you from its gamma radiation. The more mass the better, whether it is lead, earth, concrete, water, etc. The amount of mass that’ll absorb 1/2 of the gamma rays penetrating it is considered to have a Protective Factor (PF) of 2 as compared to an unprotected person in the open at the same location. If the mass is sufficient to stop 99% of the gamma radiation it would have a PF of 100 and if it stopped 99.9% it would be considered a PF of 1000 as it reduced the incoming radiation to only 1/1000th.

http://www.radshelters4u.com/index3.htm#a2

The denser and thicker the barrier substance, the better its shielding properties. Where every 3.6″ of earth cuts the incoming gamma radiation in half, thus doubling the PF, it would only take 2.4″ of concrete because it is even denser. Of course, earth is cheaper, but where concrete had been used in the construction of a shelter it’ll be providing even additional barrier protection. Also, the tenth-value thickness, in inches, for steel is 3.3; for concrete, 11; for earth, 16; for water, 24; for wood, 38. That means that where you have those thicknesses you’ll have only 1/10th as much gamma radiation pass through with that barrier material.

http://www.radshelters4u.com/index3.htm#a2

Protection Factor (PF)

The bare minimum FEMA recommended PF to strive for is a PF40, which means that the mass was sufficient to reduce the incoming radiation to 1/40th of the dose you’d receive outside if unprotected. This would be barely sufficient protection in most all fallout areas requiring sheltering, and especially deficient for the heavier fallout nearer ground zero or in a rainout created hot spot downwind. It is considered woefully less than what’s required by many experts. However, as you’ll see below, it’s too easy not to achieve PF’s of 200, 300, or 400 or more and it would be prudent to do so. (Just 3.6 inches of packed earth reduces the gamma radiation penetration by half which means you have a PF of 2. With 18 inches you have a PF 32 and with 30 inches it’s over PF 300 and with 3 feet of earth you are at about 1000 PF.)

http://www.radshelters4u.com/index3.htm#a2

This degrading effect above, and also illustrated below, is called the “Seven-Ten Rule”. For every seven times older the fallout becomes, it has also decayed to 1/10th of its strength. So, 90% of the gamma radiation is gone after the first 7 hours. Then, 90% of that remaining 10 percent is largely gone after two days. This is the ‘good news’ and why prompt sheltering is both effective and viable and should be seriously explored and embraced by all.

http://www.radshelters4u.com/index3.htm#a2

Expedient blast shelters

Fifteen-psi blast shelters will survive as close as about 1.5 miles from ground zero of a 1-megaton surface burst, and about 2.3 miles from ground zero or a 1-megaton air burst. Except in high-density urban areas where the air supply openings and exits of shelters are all too likely to be covered with blast-hurled debris, the area in which people inside good earth- covered 15-psi blast shelters would be killed would be only about 1/6th as large as the area in which most people sheltered in typical American homes probably would die from blast and fire effects alone.

http://www.oism.org/nwss/s73p939.htm

Hiroshima earth shelter

Figure D.1 shows a Hiroshima shelter that people with hand tools could build in a day, if poles or timber were available. This shelter withstood blast and fire at an overpressure range of about 65 psi. Its narrow room and a 3-foot-thick earth cover brought about effective earth arching; this kept its yielding wooden frame from being broken.

Fig. D. 1. A small, earth-covered backyard shelter with a crude wooden frame-undamaged, although only 300 yards from ground zero at Hiroshima.

Although the shelter itself was undamaged, its occupants would have been fatally injured because the shelter had no blast door. The combined effect of blast waves, excessive pressure, blast wind, and burns from extremely hot dust blown into the shelter (the popcorning effect) and from the heated air would have killed the occupants. For people to survive in areas of severe blast, their shelters must have strong blast doors.

In nuclear weapons tests in the Nevada desert, box-like shelters built of lumber and covered with sandy earth were structurally undamaged by 10- to 15-psi blast effects. However, none had blast doors, so occupants of these open shelters would have been injured by blast effects and burned as a result of the popcorning effect. Furthermore, blast winds blew away much of the dry, sandy earth mounded over the shelters for shielding; this resulted in inadequate protection against fallout radiation.

http://www.oism.org/nwss/s73p939.htm

In Nagasaki, some people survived uninjured who were far inside tunnel shelters built for conventional air raids and located as close as one-third mile from ground zero (the point directly below the explosion). This was true even though these long, large shelters lacked blast doors and were deep inside the zone within which all buildings were destroyed. (People far inside long, large, open shelters are better protected than are those inside small, open shelters.)

Many earth-covered family shelters were essentially undamaged in areas where blast and fire destroyed all buildings. Figure 1.5 shows a typical earth covered, backyard family shelter with a crude wooden frame. This shelter was essentially undamaged, although less than 100 yards from ground zero at Nagasaki.4 The calculated maximum overpressure (pressure above the normal air pressure) was about 65 pounds per square inch (65 psi). Persons inside so small a shelter without a blast doorwould have been killed by blast pressure at this distance from the explosion. However, in a recent blast test,5 an earth-covered, expedient Small-Pole Shelter equipped with blast doors was undamaged at 53 psi. The pressure rise inside was slight not even enough to have damaged occupants’ eardrums. If poles are available, field tests have indicated that many families can build such shelters in a few days.

http://www.oism.org/nwss/s73p912.htm

Shielding, or Screening From Blast – Report by The Manhattan Engineer District, June 29, 1946

The outstanding example of shielding was that afforded by the hills in the city of Nagasaki; it was the shielding of these hills which resulted in the smaller area of devastation in Nagasaki despite the fact that the bomb used there was not less powerful. The hills gave effective shielding only at such distances from the center of explosion that the blast pressure was becoming critical – that is, was only barely sufficient to cause collapse – for the structure. Houses built in ravines in Nagasaki pointing well away from the center of the explosion survived without damage, but others at similar distances in ravines pointing toward the center of explosion were greatly damaged. In the north of Nagasaki there was a small hamlet about 8,000 feet from the center of explosion; one could see a distinctive variation in the intensity of damage across the hamlet, corresponding with the shadows thrown by a sharp hill.

Shelters that survived intact

Twelve different types of expedient shelters were blast-tested by Oak Ridge National Laboratory during three of Defense Nuclear Agency’s blast tests.5 Two of these tests each involved the detonation of a million pounds or more of conventional explosive; air-blast effects equivalent to those from a 1-kiloton nuclear surface burst were produced by these chemical explosions.

Several of these shelters had expedient blast doors which were closed during the tests. Figure D.2 shows the undamaged interior of the best expedient blast shelter tested prior to 1978, an improved version of the Small-Pole Shelter described in Appendix A. Its two heavy plywood blast doors excluded practically all blast effects; the pressure inside rose only to 1.5 psi an overpressure not nearly high enough to break eardrums. The only damage was to the expedient shelter-ventilating pump (a KAP) in the stoop-in entryway. Two men worked about 5 minutes to replace the 4 flap-valves that were blown loose.

Fig. D.2. Undamaged interior of a Small-Pole Shelter after blast testing at the 53-psi overpressure range. Large buildings would have been completely demolished.

When blast-tested at 5-psi overpressure, not even the weakest covered-trench shelters with unsupported earth walls (described in Appendix A) were damaged structurally. However, if the covering earth were sandy and dry and if it were exposed to the blast winds of a megaton explosion at the 5-psi overpressure range, so much earth would be blown away that the shelter would give insufficient protection against fallout radiation. Much of the dry, shielding earth mounded over some of the above- ground shelters was, in fact, removed by the blast winds of these relatively small test explosions, even at the lower overpressure ranges at which homes would be wrecked. In contrast, in blast tests where the steeply mounded earth was damp, little blast-wind erosion resulted. (The reader should remember that even if shelters without blast doors are undamaged, the occupants are likely to suffer injuries.)

http://www.oism.org/nwss/s73p912.htm

Fig. D.3. Effective earth arching in the earth covering of this 4-ft-wide Pole-Covered Trench Shelter prevented a single pole from being broken by blast forces that exerted a downward force of 53 psi (over 3-1/2 tons per square foot) on the overlying earth.

This picture shows the unbroken roof of a 4- foot-wide Pole-Covered Trench Shelter that was built in rock-like soil and blast tested where the blast pressure outside was 53 psi. Its strong blast doors prevented the blast wave from entering. Without the protection of earth arching that developed in the 5 feet of earth cover over the yielding roof poles, the poles would have been broken like straws. In contrast, the ground shock and earth pressure produced by 1-kiloton blast effects almost completely collapsed the unsupported, rock-like earth walls.

http://www.oism.org/nwss/s73p939.htm

Fig. D.4. Post-blast interior of an Above- ground, Door-Covered Shelter that survived 1-kiloton blast effects at the 5.8-psi overpressure range. The shelter walls were made of bedsheets containing earth, as described in Appendix A.

Fig. D.5. A dummy in an unshored Pole-Covered Trench Shelter as it is struck by collapsing rock-like earth walls. The photo also shows the shelter’s blanket-curtains as they are torn and blown into the shelter by the 180-mph blast wind. (Immediately after this photo was taken, the dummies were hit by the airborne blast wave and blast wind. Outside, the blast wind peaked at about 490 mph.)

Fig. D.6. Dummies after ground shock from 1-kiloton blast effects at the 20-psi range had collapsed the rock-like walls of a hardened desert soil called caliche. The dummies’ steel “bones” and “‘joints” prevented them from being knocked down and buried. The fallen caliche all around them kept them from being blown over by the air blast wave and 180-mph blast wind that followed.

http://www.oism.org/nwss/s73p939.htm

http://www.lastalive.com/survival_guide/nuclear/nuclear_survival.htm

SHIELDING and SHELTER

“When the fire burnt itself out, there appeared a completely changed, vast, colorless world that made you think it was the end of life on earth. In a heap of ashes lay the debris of the disaster and charred trees, presenting a gruesome scene. The whole city became extinct. Citizens who were in Matsuyama township, the hypocenter, were all killed instantly, excepting a child who was in an air-raid shelter.” [Nagasaki]

http://www.gensuikin.org/english/photo.html

Decontamination

Washing of the steel to decontaminate it of radioactivity

[36] New York City and Bush White House WANT the WTC clean-up workers/witnesses dead. U.S. Gov’t had “wash down” equipment for rescue workers at WTC–though they refused to use them.

“Another thing. The government spent millions of dollars on wash down machines for workers, but they never even used them once. Why? Well, they never even gave us protective gear or any protective clothing. They just didn’t care about people, but they sure did care about getting the billions of gold out from the basement and they sure cared about hauling the steel away as quick as they could.

http://portland.indymedia.org/en/2005/11/329129.shtml

[37] Knowing the radiological dangers may lead back to the Bush Administration and Giuliani when they authorize the steel to be illegally shipped overseas before investigation. The decision is made to wash down the steel though NOT wash down the rescue workers. THEY WASH DOWN THE STEEL IN A CONTAMINATION CENTER UPON LEAVING WTC SITE, THOUGH IGNORE THE WORKERS.
“The second reason I know they lied is because I found out after the trucks that hauled the steel out left the WTC, they went into a wash down contamination center. What does that tell yah

http://portland.indymedia.org/en/2005/11/329129.shtml

[38] FBI, CIA, EPA, U.S. Government observers tell everyone the lie that the WTC is safe, though the U.S. Government is saying this from a ‘safe zone’ for themselves, which they seldom if ever leave.
“And, the last thing, which is the icing on the cake, is the EPA put up this protective fence or what they called the ‘safe zone.’ And, think about it, there were hundreds of FBI and CIA there every day but they always stayed in the ‘safe zone’ and on the other side of the fence. Why?

http://portland.indymedia.org/en/2005/11/329129.shtml

[39] The officials know it is “contaminated”, and tell the workers to leave their clothes on site
“MT: I think we should just keep going from the beginning. When we first got there, we were told where we could go and where we couldn’t go. There were different places that you were not to go to. One of the things you were not to go to and they claimed it was for safety was down in the garages, the parking garages. They were very flooded. There were a lot of problems like that. All the apartments around there were all sealed off. A lot of things were very much sealed off. However, at the same time, right from the beginning, one of the things that I noticed was there was looting everywhere. People were stealing clothes that were meant for us. The rescue people – when our clothes got so contaminated, we were told not to bring our clothes off that site. Don’t wear anything on the site you’re not prepared to leave there because it’s contaminated.”

http://portland.indymedia.org/en/2005/03/314483.shtml

http://portland.indymedia.org/en/2006/06/341768.shtml

Steel sent to China

Regarding 9/11, never forget that whatever radionuclides may have been created were sent to China, or otherwise were not allowed to be studied. This remarkable article states that before the steel was shipped to China, it was “first sent to be washed down”— a standard method of decreasing radiation levels!

http://wtcdemolition.blogspot.com/2007/06/on-issue-of-nuclear-demolition-of-wtc.html

Shielding provided by smog and cloud cover

In most places however, besides fog, smog, haze or clouds, there are buildings, trees, hills and other objects that would also block and reduce some portion of the thermal pulse. In fact, the more densely built up an area is then the less likely the inhabitants would be exposed to suffer the full impact of the thermal pulse. Of course, though, they may still have to deal with the resultant fires created by the thermal pulse and from any blast damage.

http://www.radshelters4u.com/#100

Calculation of Yield

1 KT Nuclear Device
Summary of Impact of 1 KT Nuclear Blast

1 KT – Effective Range for Blast Energy
350m LD50 11m/sec – LD50 means 50% mortality (1148.29 feet = 0.2174792 mile)
550m ED50 4.3m/sec – ED50 would affect 50% population (1804.46 feet = 0.3417538 mile)
750m Penetrating Wounds 55m/sec (2460.63 feet = 0.4660284 mile)

1 KT- Blast Energy and Static Overpressure
150m LD50 50psi – LD50 means 50% mortality (492.126 feet = 0.0932057 mile)
300m ED50 20psi – ED50 would affect 50% population (984.252 feet = 0.1864114 mile)
700m Eardrum Rupture 5 psi (2296.59 feet = 0.4349602 mile)

1 KT -Safe Separation Distance for Eye Injuries
Weapon Yield – 1 KT
Detonation Altitude-300 Meters
Personnel Altitude – Sea Level
Daytime Visibility – 46 km (28.5830748 mile)
Retinal Burns – 16.7 km (10.3768989 mile)
Flash Blindness – 5.9 km (3.66609 miles)

1 KT – Effective Range for Thermal Energy Infrared
700m – 7 cal/cm2 (2296.59 feet = 0.4349602 mile)
800m – 4 cal/cm2 (2624.67 feet = 0.4970966 mile)
1200m – 2 cal/cm2 (3937.01 feet = 0.7456458 mile)

http://www.unitedstatesaction.com/nuclear-low-yield-weapons-impact.htm

Map of damage and distance from the hypocenter

Summary of the effects

The following table summarizes the most important effects of nuclear explosions under certain conditions.

Effects	Explosive yield / Height of Burst
Effects	1 kT / 200 m	20 kT / 540 m	1 MT / 2.0 km	20 MT / 5.4 km
Blast—effective ground range GR / km
Urban areas almost completely levelled (20 PSI)	0.2	0.6	2.4	6.4
Destruction of most civil buildings (5 PSI)	0.6	1.7	6.2	17
Moderate damage to civil buildings (1 PSI)	1.7	4.7	17	47
Thermal radiation—effective ground range GR / km
Conflagration	0.5	2.0	10	30
Third degree burns	0.6	2.5	12	38
Second degree burns	0.8	3.2	15	44
First degree burns	1.1	4.2	19	53
Effects of instant nuclear radiation—effective slant range¹ SR / km
Lethal² total dose (neutrons and gamma rays)	0.8	1.4	2.3	4.7
Total dose for acute radiation syndrome²	1.2	1.8	2.9	5.4

http://www.reference.com/browse/wiki/Effects_of_nuclear_explosions

Earthquake

The pressure wave from an underground explosion will propagate through the ground and cause a minor earthquake. Theory suggests that a nuclear explosion could trigger fault rupture and cause a major quake at distances within a few tens of kilometers from the shot point.

http://www.reference.com/browse/wiki/Effects_of_nuclear_explosions

Earthquake trench in Liberty Street

As we were installing the wells on October 7th and 8th … we discovered a five to six inch crack in the street [Liberty St] — the wall was moving and we had to take immediate action.

http://www.pbs.org/americarebuilds/engineering/engineering_wall_02.html

Bunker buster in action

VIDEO: Nbbd_hi Dailymotion

Click on image above to view video

http://www.dailymotion.com/skyblue09/video/4708848

Comment: Notice that the blast is from a below ground explosion, similar to the World Trade Center ones which were buried in the basement (“The Bathtub” and slurry walls) and were encased (in concrete and steel).

The fact that the explosions occur underground in the case of the bunker buster means that the effects of the nuclear explosion are all reduced (blast, thermal and radiation effects). [See “Mushrooms and Craters” and “Nuclear Strike”]

http://www.fas.org/faspir/2001/v54n1/weapons.htm

Nuclear bunker buster

Fig. 2 The Pentagon has a growing collection of high precision conventional weapons capable of defeating hardened targets. In this sled-driven test, the GBU-28 laser guided bomb with its improved BLU-113 warhead penetrates several meters of reinforced concrete.

http://www.fas.org/faspir/2001/v54n1/weapons.htm

Underground detonations limit collateral damage

Fig. 1 Diagrams like this one give the false impression that a low-yield earth penetrating nuclear weapon would “limit collateral damage” and therefore be relatively safe to use. In fact, because of the large amount of radioactive dirt thrown out in the explosion, the hypothetical 5-kiloton weapon discussed in the accompanying article would produce a large area of lethal fallout. (Philadelphia Inquirer/ Cynthia Greer, 16 October 2000.)

http://www.fas.org/faspir/2001/v54n1/weapons.htm

The B61-11 Nuclear Bomb

However, mini-nuke advocates — mostly coming from the nuclear weapons labs — argue that low-yield nuclear weapons should be designed to destroy even deeper targets.

The US introduced an earth-penetrating nuclear weapon in 1997, the B61-11, by putting the nuclear explosive from an earlier bomb design into a hardened steel casing with a new nose cone to provide ground penetration capability. The deployment was controversial because of official US policy not to develop new nuclear weapons. The DOE and the weapons labs have consistently argued, however, that the B61-11 is merely a “modification” of an older delivery system, because it used an existing “physics package.”

The earth-penetrating capability of the B61-11 is fairly limited, however. Tests show it penetrates only 20 feet or so into dry earth when dropped from an altitude of 40,000 feet. Even so, by burying itself into the ground before detonation, a much higher proportion of the explosion energy is transferred to ground shock compared to a surface bursts. Any attempt to use it in an urban environment, however, would result in massive civilian casualties. Even at the low end of its 0.3-300 kiloton yield range, the nuclear blast will simply blow out a huge crater of radioactive material, creating a lethal gamma-radiation field over a large area.

http://www.fas.org/faspir/2001/v54n1/weapons.htm

Containment

Just how deep must an underground nuclear explosion be buried in order for the blast and fallout to be contained?

The US conducted a series of underground nuclear explosions in the 1960s — the Plowshare tests — to investigate the possible use of nuclear explosives for excavation purposes. Those performed prior to the 1963 Atmospheric Test Ban Treaty, such as the Sedan test shown in Figure 4, were buried at relatively shallow depths to maximize the size of the crater produced.

CaptionFig. 4 The 100 KT Sedan nuclear explosion, one of the Plowshares excavation tests, was buried at a depth of 635 feet. The main cloud and base surge are typical of shallow-buried nuclear explosions. The cloud is highly contaminated with radioactive dust particles and produces an intense local fallout.

In addition to the immediate effects of blast, air shock, and thermal radiation, shallow nuclear explosions produce especially intense local radioactive fallout. The fireball breaks through the surface of the earth, carrying into the air large amounts of dirt and debris. This material has been exposed to the intense neutron flux from the nuclear detonation, which adds to the radioactivity from the fission products. The cloud typically consists of a narrow column and a broad base surge of air filled with radioactive dust which expands to a radius of over a mile for a 5 kiloton explosion.1 In the Plowshare tests, roughly 50 percent of the total radioactivity produced in the explosion was distributed as local fallout — the other half being confined to the highly-radioactive crater.

In order to be fully contained, nuclear explosions at the Nevada Test Site must be buried at a depth of 650 feet for a 5 kiloton explosive — 1300 feet for a 100-kiloton explosive.2 Even then, there are many documented cases where carefully sealed shafts ruptured and released radioactivity to the local environment.

Notes:

¹The base surge radius scales roughly as 4000 W^1/3_ktfeet, where W_ktis the yield in kilotons.

²In general, NTS tests are buried at depths of D 450 W_kt^1/3.4 feet to be fully contained.

http://www.fas.org/faspir/2001/v54n1/weapons.htm

Crater

Fig. 5 Underground nuclear tests must be buried at large depths and carefully sealed in order to fully contain the explosion. Shallower bursts produce large craters and intense local fallout. The situation shown here is for an explosion with a 1 KT yield and the depths shown are in feet. Even a 0.1 KT burst must be buried at a depth of approximately 230 feet to be fully contained. (Adapted from Terry Wallace, with permission.)

http://www.fas.org/faspir/2001/v54n1/weapons.htm

Containment

Building construction – inner core – Chapter 2

The WTC towers, also known as WTC 1 and WTC 2, were the primary components of the seven building World Trade Center complex. Each of the towers encompassed 110 stories above the Plaza level and seven levels below. WTC 1 (the north tower) had a roof height of 1,368 feet, briefly earning it the title of the world’s tallest building. WTC 2 (the south tower) was nearly as tall, with a roof height of 1,362 feet. WTC 1 also supported a 360-foot-tall television and radio transmission tower. Each building had a square floor plate, 207 feet 2 inches long on each side. Corners were chamfered 6 feet 11 inches. Nearly an acre of floor space was provided at each level. A rectangular service core with overall dimensions of approximately 87 feet by 137 feet, was present at the center of each building, housing 3 exit stairways, 99 elevators, and 16 escalators. Figure 2-1 presents a schematic plan of a representative above ground floor. [..]

Construction of the perimeter-wall frame made extensive use of modular shop prefabrication. In general, each exterior wall module consisted of three columns, three stories tall, interconnected by the spandrel plates, using all-welded construction. [..]

At the building base, adjacent sets of three columns tapered to form a single massive column, in a fork-like formation [tridents]. [..]

Twelve grades of steel, having yield strengths varying between 42 kips per square inch (ksi) and 100 ksi, were used to fabricate the perimeter column and spandrel plates as dictated by the computed gravity and wind demands. Plate thickness also varied, both vertically and around the building perimeter, to accommodate the predicted loads and minimize differential shortening of columns across the floor plate. In upper stories of the building, plate thickness in the exterior wall was generally 1/4 inch. At the base of the building, column plates as thick as 4 inches were used. [..]

Floor construction typically consisted of 4 inches of lightweight concrete on 1-1/2-inch, 22-gauge non-composite steel deck. In the core area, slab thickness was 5 inches.

Concrete Core

_1540044_world_trade_structure300

The design was a “tube in a tube” construction where the steel reinforced, cast concrete interior tube, was surrounded with a structural steel framework configured as another tube with the load bearing capacity bias towards the perimeter wall with the core acting to reduce deformation of the steel structure maximizing its load bearing capacity. All steel structures with the proportions of the WTC towers have inherent problems with flex and torsion. Distribution of gravity loads was; perimeter walls 50%, interior core columns 30% core 20%. […]

Both the WTC 1 & WTC 2 towers had a rectangular cast concrete core structure formed into rectangular cells that had elevators and stairways in them. [..]

North Tower core

Below I’ve crudely altered an earlier FEMA core diagram to show how the concrete core, interior walls and hallways were configured through the entire height of the north towers “tube in a tube” construction.

Interior walls of the core were not continuos vertically, they were interrupted by hallways perpendicularly opposed with each floor. Doorways appeared on each floor on every face every other floor. The tops of the interior walls of the concrete core served as the support for the steel interior concrete forms that had to be disassembled and lifted 40 feet to be set for the next pour. Exterior forms were plywood.

The hallway/door scheme was changed higher up. Also, the south tower was different, 2 hallways crossed the short axis of the core, perhaps with one perpendicular.

http://concretecore.741.com/

WTCoverhead.railscolumns

corecornerarrow.col

http://concretecore.741.com/

Core – Chapter 2

http://www.serendipity.li/wot/wtc_ch2.htm

External wall construction – box columns and spandrels

shows a cross-section through typical floor framing.

http://www.serendipity.li/wot/wtc_ch2.htm

Bathtub Construction

Figure 2-11. Location of subterranean structure.

A deep subterranean structure was present beneath the WTC Plaza (Figure 2-11) and the two towers. The western half of this substructure, bounded by West Street to the west and by the 1/9 subway line that extends approximately between West Broadway and Greenwich Street on the east, was 70 feet deep and contained six subterranean levels. The structure housed a shopping mall and building mechanical and electrical services, and it also provided a station for the PATH subway line and parking for the complex.

Prior to construction, the site was underlain by deep deposits of fill material, informally placed over a period of several hundred years to displace the adjacent Hudson River shoreline and create additional usable land area. In order to construct this structure, the eventual perimeter walls for the subterranean structure were constructed using the slurry wall technique. After the concrete wall was cured and attained sufficient strength, excavation of the basement was initiated. As excavation proceeded downward, tieback anchors were drilled diagonally down through the wall and grouted into position in the rock deep behind the walls. These anchors stabilized the wall against the soil and water pressures from the unexcavated side as the excavation continued on the inside. After the excavation was extended to the desired grade, foundations were formed and poured against the exposed bedrock, and the various subgrade levels of the structure were constructed.

Floors within the substructure were of reinforced concrete flat-slab construction, supported by structural steel columns. Many of these steel columns also provided support for the structures located above the plaza level. After the floor slabs were constructed, they were used to provide lateral support for the perimeter walls, holding back the earth pressure from the unexcavated side. The tiebacks, which had been installed as a temporary stabilizing measure, were decommissioned by cutting off their end anchorage hardware and repairing the pockets in the slurry wall where these anchors had existed.

Tower foundations beneath the substructure consisted of massive spread footings, socketed into and bearing directly on the massive bedrock.

http://www.serendipity.li/wot/wtc_ch2.htm

Shifting Shoreline

GEORGE TAMARO: In the early 1600s, Henry Hudson sailed his ships up the river that would later bear his name, landing on the eastern shore line. During one of his visits, one of his ships, the Tijger, burned to the waterline and sank at the shoreline at approximately Dey and Greenwich streets. Successive landfilling extended the shoreline, first to the colonial high water line and then to the old bulkhead line, which was the formal edge of the city in the 1900s. During the World Trade Center construction, the dig unearthed cannon balls, ship parts, and old wine bottles. Material removed from the site was dumped into a landfill, here identified as the World Trade Center disposal area. This debris and a subsequent landfill pushed the edge of the city out to the Battery Park City bulkhead that is the current western edge of Manhattan. http://www.pbs.org/americarebuilds/engineering/engineering_site_01.html

The Finished Excavation, circa 1968

GEORGE TAMARO: We excavated down to depths of 70 feet for three reasons. First, it was important to carry the foundations down to bedrock, so that there would be substantial supporting material to carry the loads of the towers. Secondly, it was necessary to completely expose the old PATH tubes and to eventually redirect them within the bathtub. Lastly, the station for the PATH system was moved to the lower elevation of the PATH trains, so the bottom of the excavation had to be carried down at least to the level of the tunnels, if not below, for a new station which was located on the eastern edge of the slurry wall, within the bathtub. Directly east of the Greenwich Street slurry wall is the 1 and 9 subway train, approximately 20 to 30 feet below street level.

URL: http://www.pbs.org/americarebuilds/engineering/engineering_site_03.html

The Slurry Wall — An Innovation At the Time

GEORGE TAMARO: An Italian innovation, slurry walls were first used in 1949. The Port Authority was very courageous to use them in 1967, since slurry walls had not previously been used to this particular extent. The first step was to excavate a slot in the ground several feet across that ultimately formed the shape of the reinforced concrete wall. Using a clamshell bucket, we excavated soil from within this slot, replacing the ground with a mixture of clay and water, which kept the slot from collapsing. When we got to the top of the bedrock, we chiseled a key into the rock at the bottom, giving us a watertight connection. We then installed a reinforcing steel cage into the slot.
Once the cage was secured in position, we put concrete into a hopper at the top of a long “tremie” pipe that extended down to the bottom of the slot. As we placed concrete into the slot forming a panel, we drew slurry out of the slot, reversing the initial excavation process; the three-foot concrete wall panel then hardened in the ground. During excavation, the face of the wall was exposed one level at a time. To support the wall against pressure from the water, soil and streets, we drilled steel tieback tendons through the wall, down 100 feet to the rock, and then 35 into the rock for an anchorage. Later, we cut the tieback anchors and buried them within the wall once the new basement slabs were installed and the floor system could support the slurry wall.

http://www.pbs.org/americarebuilds/engineering/engineering_site_04.html

http://s18.photobucket.com/albums/b108/janedoe444/ARG/Image86.jpg

Another view of the bathtub

http://drjudywood.com/articles/DEW/StarWarsBeam4.html

Pre and Post Ground Zero

A Bird’s Eye View

GEORGE TAMARO: On September 12th, there were massive amounts of debris 60 to 70 feet above ground — the equivalent of a six- to seven-story building. World Trade Centers 1, 2, 3 and 7 were almost completely destroyed. WTC 6 had a massive hole in the center.

http://www.pbs.org/americarebuilds/engineering/engineering_damage_01.html

Subsurface burst and effects

Subsurface Burst. A subsurface burst is an explosion in which the point of the detonation is beneath the surface of land or water. Cratering will generally result from an underground burst, just as for a surface burst. If the burst does not penetrate the surface, the only other hazard will be from ground or water shock. If the burst is shallow enough to penetrate the surface, blast, thermal, and initial nuclear radiation effects will be present, but will be less than for a surface burst of comparable yield. Local fallout will be very heavy if penetration occurs.

http://www.unitedstatesaction.com/nuclear-low-yield-weapons-impact.htm

Nuclear bunker buster

The RNEP would be used on targets that may be immune to conventional weapons. Its backers claim it would create little contamination above ground, but critics say that it would produce huge amounts of nuclear fallout. The RNEP may also remove the distinction between a nuclear deterrent and conventional weapons, increasing the risk of a nuclear exchange.

US law prevents development of new “mini-nukes” that have an explosive yield of less than 5 kilotons. But the RNEP falls outside this ban because it is not a new weapon.

Rather, it will be a modification of an existing nuclear bomb, probably a highly modified B61, sources say, a weapon whose explosive yield can be set from anything between 0.3 and 340 kilotons. The bomb uses fission at low yields but is a fusion (hydrogen) bomb at high yields. The Hiroshima fission bomb had a yield of 12 kilotons.

Underground explosions are 10 to 15 times as effective against buried facilities as airbursts. A conventional bunker-buster is dropped from high altitude and hits the ground at enormous speed. It penetrates earth, rock and concrete before exploding. A nuclear version has the advantage of a far more powerful shock wave, increasing the depth of its destructive effect.

The US already has around fifty ‘penetrating’ nuclear weapons in its stockpile, but these can only reach a depth of six metres in earth. David Wright, a nuclear-weapons expert at the Union of Concerned Scientists in Washington DC, says this would not be nearly enough to contain the radioactivity.

“Even for a 0.3-kiloton explosion, you would need a burial depth of about 70 metres in dry soil and about 40 metres in dry, hard rock to contain the blast,” Wright says. An explosion at the maximum depth achievable so far would throw thousands of tonnes of highly radioactive debris into the air.

http://www.newscientist.com/article.ns?id=dn3016

Richter magnitude and TNT-equivalent seismic energy yield

Richter     TNT for Seismic    Example
Magnitude      Energy Yield    (approximate)          

-1.5                6 ounces   Breaking a rock on a lab table
 1.0               30 pounds   Large Blast at a Construction Site
 1.5              320 pounds
 2.0                1 ton      Large Quarry or Mine Blast
 2.5              4.6 tons
 3.0               29 tons
 3.5               73 tons
 4.0            1,000 tons     Small Nuclear Weapon
 4.5            5,100 tons     Average Tornado (total energy)
 5.0           32,000 tons
 5.5           80,000 tons     Little Skull Mtn., NV Quake, 1992
 6.0        1 million tons     Double Spring Flat, NV Quake, 1994
 6.5        5 million tons     Northridge, CA Quake, 1994
 7.0       32 million tons     Hyogo-Ken Nanbu, Japan Quake, 1995; Largest Thermonuclear Weapon
 7.5      160 million tons     Landers, CA Quake, 1992
 8.0        1 billion tons     San Francisco, CA Quake, 1906
 8.5        5 billion tons     Anchorage, AK Quake, 1964
 9.0       32 billion tons     Chilean Quake, 1960
10.0       1 trillion tons     (San-Andreas type fault circling Earth)
12.0     160 trillion tons     (Fault Earth in half through center,
                               OR Earth's daily receipt of solar energy)

http://www.seismo.unr.edu/ftp/pub/louie/class/100/magnitude.html

Summary of Impact of 1 KT Nuclear Blast

http://www.unitedstatesaction.com/nuclear-low-yield-weapons-impact.htm

Formulae to calculate effects

The three categories of immediate effects are: blast, thermal radiation (heat), and prompt ionizing or nuclear radiation. Their relative importance varies with the yield of the bomb. At low yields, all three can be significant sources of injury. With an explosive yield of about 2.5 kt, the three effects are roughly equal. All are capable of inflicting fatal injuries at a range of 1 km.

The equations below provide approximate scaling laws for relating the destructive radius of each effect with yield:

r_thermal = Y^0.41 * constant_th
r_blast = Y^0.33 * constant_bl
r_radiation = Y^0.19 * constant_rad

If Y is in multiples (or fractions) of 2.5 kt, then the result is in km (and all the constants equal one). This is based on thermal radiation just sufficient to cause 3rd degree burns (8 calories/cm^2); a 4.6 psi blast overpressure (and optimum burst height) [comment: the WTC explosions were not geared to produce an optimum burst effect]; and a 500 rem radiation dose.

The underlying principles behind these scaling laws are easy to explain. The fraction of a bomb’s yield emitted as thermal radiation, blast, and ionizing radiation are essentially constant for all yields, but the way the different forms of energy interact with air and targets vary dramatically.

Air is essentially transparent to thermal radiation. The thermal radiation affects exposed surfaces, producing damage by rapid heating. A bomb that is 100 times larger can produce equal thermal radiation intensities over areas 100 times larger. The area of an (imaginary) sphere centered on the explosion increases with the square of the radius. Thus the destructive radius increases with the square root of the yield (this is the familiar inverse square law of electromagnetic radiation). Actually the rate of increase is somewhat less, partly due to the fact that larger bombs emit heat more slowly which reduces the damage produced by each calorie of heat. It is important to note that the area subjected to damage by thermal radiation increases almost linearly with yield.

Blast effect is a volume effect. The blast wave deposits energy in the material it passes through, including air. When the blast wave passes through solid material, the energy left behind causes damage. When it passes through air it simply grows weaker. The more matter the energy travels through, the smaller the effect. The amount of matter increases with the volume of the imaginary sphere centered on the explosion. Blast effects thus scale with the inverse cube law which relates radius to volume.

The intensity of nuclear radiation decreases with the inverse square law like thermal radiation. However nuclear radiation is also strongly absorbed by the air it travels through, which causes the intensity to drop off much more rapidly.

These scaling laws show that the effects of thermal radiation grow rapidly with yield (relative to blast), while those of radiation rapidly decline. [..]

A convenient rule of thumb for estimating the short-term fatalities from all causes due to a nuclear attack is to count everyone inside the 5 psi blast overpressure contour around the hypocenter as a fatality. In reality, substantial numbers of people inside the contour will survive and substantial numbers outside the contour will die, but the assumption is that these two groups will be roughly equal in size and balance out. This completely ignores any possible fallout effects.

http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html

Some sample computations using the cubic root scaling rules for size of blast and yield

Note this is based on a 4.6 psi blast overpressure and optimum burst height. In the WTC attacks, consideration for maximizing yield using an optimum burst height was not a priority. Concealment of the nature of the weapon and therefore a focus on producing as small effects as possible while still demolishing the towers was the priority. Note also that the explosion was contained within a superstrong concrete and steel frame and this provided a form of shielding and a reduction of the effects. The WTC explosions were subsurface bursts.

Yield of weapon (at optimum burst height – air burst)	Radius of the blast effect (4.6 psi)
1 kt	730 m
0.75 kt	660 m
0.6 kt	620 m
0.5 kt	585 m
0.4 kt	540 m
0.33 kt	511 m
0.3 kt	490 m
0.25 kt	460 m
0.2 kt	430 m
0.1 kt	340 m

Radii of effects of nuclear weapons

http://www.fas.org/nuke/guide/usa/doctrine/dod/fm8-9/1ch3.htm

Nuclear effects calculator

Click on image above to go to the map with calculator

Red Circle: Intense heat from the explosion will likely cause widespread fires within this region.

Blue Circle: Most homes are completely destroyed and stronger commercial buildings will be severely damaged due to the high pressure blast wave in this region.

Yellow Circle: Moderate damage to buildings causing some risk to people due to flying debris is caused by the blast wave in this region.

For those interested in the technical details, this tool is based upon data obtained from The Effects of Nuclear Weapons. The blue and yellow contours mark overpressures of 5 psi and 2 psi, respectively. The blast radius scales with the weapon’s yield as a cube root law. Choosing to deliver the bomb by aircraft assumes it is flying at an altitude which maximizes the size of the 5 psi contour. The red contour marks the region in which the thermal flux is 15 cal/cm2 or higher. This is likely to cause many materials to begin combustion, which can then spread into much larger fires. This model, however, does not take into account obstructions that may block some of the heat radiating from the fireball.

http://www.fas.org/main/content.jsp?formAction=297&contentId=367

Another Nuclear weapons effects calculator

Image: Click on image above to view site with calculator. Note that the calculator calculates effects for an air burst weapon. The WTC explosion was an underground burst. There was much shielding by the rock foundations and the slurry wall of the Bathtub. Hence the effects, including the radius of effects (blast, thermal, radiation) will be different to the ones obtained from using the calculator.

Notes

All figures assume optimum burst height
Thermal radiation is non-ionizing electromagnetic radiation which has a significant heating effect. Air is virtually transparent to thermal radiation. At the destructive radius, the thermal radiation intensity is sufficient to cause lethal burns.
The first air blast is 4.6psi overpressure, which is sufficient to collapse most residential and industrial structures. Note that exposed humans can actually survive such a blast, about 1/3 bar above standard. However, that much pressure exerted against the face of a building exerts very high force (a 40 foot tall, 50 foot wide structure would be hit with more than 600 tons-force).
The second air blast category is 20psi overpressure, which is sufficient to destroy virtually any large above-ground structure and cause nearly 100% fatalities.
Ionizing radiation is electromagnetic radiation of sufficient frequency (and hence energy) to literally “knock off” electrons from atoms, thus ionizing them. Ionizing radiation is extremely dangerous but it is also strongly absorbed by air, unlike thermal radiation. At the 500rem dosage, mortality is between 50% and 90%, although this can be mitigated with prompt and sophisticated medical care (which may not be available in the aftermath of a nuclear attack).
Fireball duration is based on emission intensity reduction to 10% of peak.
Fireball radius is based on a scaling law from “The Effects of Nuclear Weapons” (1977), Chapter IIc, from excerpts reprinted at EnviroWeb. According to that source, fireball radius scales with (Y^0.4), where Y is yield. Also note that a ground-contact airburst creates a larger fireball because some of the energy is reflected back up from the surface.

http://www.stardestroyer.net/Empire/Science/Nuke.html

How much is 10 kilotons?

http://members.tripod.com/motomom/Nuclear

Staircase B Survivors

Only twenty people were pulled alive from the debris after the towers’ collapse:

Fourteen people, including a dozen firefighters, one police officer (a Port Authority policeman), and civilian secretary Josephine Harris, 59, were in Stairway “B” on the 1st through 6th floors of the North Tower when it collapsed. The firemen had stopped to help escort Josephine from the building at the time of the collapse. They crawled out and were then escorted alive from an air pocket in the debris. The fourteen survivors from stairway B in the North tower include (spellings uncertain):

Firefighter Mickey Kross (Engine Company 16)

Battalion Chief Rich Picciotto (11th Battalion)

Firefighter Billy Butler (Ladder 6)

Firefighter Tommy Falco (Ladder 6)

Firefighter Jim McGlynn (Engine 39)

Captain Jay Jonas (Ladder 6)

Firefighter Rob Bacon (Engine 39)

Firefighter Jeff Coniglio (Engine 39)

Firefighter Jim Efthimiaddes (Engine 39)

Officer Dave Lim (Port Authority Police K-9 Unit)

Firefighter Michael Meldrum (Ladder 6)

Firefighter Sal D’Agastino (Ladder 6)

Firefighter Matt Komorowski (Ladder 6)

Josephine Harris (civilian)

First Union Bank employee Tom Canavan, 42, and an unidentified young man were in the underground shopping mall beneath the South Tower when it collapsed. They were able to climb to the surface.

Police officers Sgt. John McLoughlin, 48, and Will Jimeno, 33, were in the underground shopping mall beneath the North Tower when it collapsed. They were pulled out by rescue workers.

Pasquale Buzzelli, 32, a structural engineer at the Port Authority, was in Stairway “B” on the 13th floor of the North Tower when it collapsed. After losing consciousness, he awoke on the surface, on top of a pile of rubble, and was carried away with minor injuries.

Genelle Guzman McMillan, 30, a secretary at the Port Authority, was in Stairway “B” on the 13th floor of the North Tower when it collapsed. She survived in an air pocket for 27 hours before she was rescued. She is famous for being the last person pulled alive from the rubble.

http://genealogytrails.com/main/sept11.html

Engine 9 Fireman’s Story

Firefighter Peter Blaich
Ladder 123 – 2 years
(was at Engine 9 on 9/11)

I came in for the day tour, so I got there about 8 o’clock and relieved the guy on the backup on the engine. A fireman, Ray Hayden, was actually standing in front of quarters and he saw what he thought was a small plane and then an explosion right into north tower. You could just make out the tips of the towers from the firehouse on Canal Street, so he got everybody in the house on standby and we were waiting to be dispatched, which we never were. Then, at that moment, it flashed on the news that the north tower was on fire. We weren’t dispatched yet, but Hayden turned everybody out. We took the satellite because we had the satellite with us. 6 Truck went. 9 Engine went and Satellite 1 went.

You could see the top of the north tower still, a lot of fire and a lot of smoke. As we got closer towards the towers, I lost the view I had from the cab of the engine. It was blocked out by the other buildings. Engine 9 pulled up on Vesey and West Street, and the satellite was behind Engine 9 and in front of 9 Engine was 6 Truck.

As soon as we pulled up, I remember getting off the rig and Lieutenant Foti from the engine said everybody grab an extra bottle along with our rollups. He’s a captain now, he was promoted after 9/11. Then he turned to me and he said if I can, take the life-saving rope and try to keep that with me as long as I could because we had jumpers at that point.

So I had the rollup, I had an extra bottle, I had the life-saving rope and then I remember looking up and seeing the first body hit one of the lower towers in the complex. And then I saw another body land not too far in front of us, right on the hood of a car. I had never imagined seeing anything like that, ever.

We proceeded into the north tower and at that point Chief Pfiefer was just setting up the command post in the north tower. It was us, 1 Truck, 7 Engine, 6 Engine, 55 Engine was there. Chief Pfiefer told us and 6 Truck to stay together and to start making our way up the B stairway, which was the attack stairway. And I heard that over the radio too B is the attack stairway. I had a radio because in 9 Engine they have the satellite, so the backup man has a radio also.

We started going up the B stairway. As we got to the third floor of the B stairway, we forced open an elevator door which was burnt on all three sides. The only thing that was remaining was the hoistway door. And inside the elevator were about – I didn’t recognize them initially, but a guy from 1 Truck said oh my God, those are people. They were pretty incinerated. And I remember the overpowering smell of kerosene. That’s when Lieutenant Foti said oh, that’s the jet fuel. I remember it smelled like if you’re camping and you drop a kerosene lamp.

The same thing happened to the elevators in the main lobby. They were basically blown out. I don’t recall if I actually saw people in there.

What got me initially in the lobby was that as soon as we went in, all the windows were blown out, and there were one or two burning cars outside. And there were burn victims on the street there, walking around. We walked through this giant blown-out window into the lobby.

There was a lady there screaming that she didn’t know how she got burnt. She was just in the lobby and then next thing she knew she was on fire. She was burnt bad. And somebody came over with a fire extinguisher and was putting water on her.

That’s the first thing that got me. That and in front of one of the big elevator banks in the lobby was a desk and I definitely made out one of the corpses to be a security guard because he had a security label on his jacket. I’m assuming that maybe he was at a table still in a chair and almost completely incinerated, charred all over his body, definitely dead. And you could make out like a security tag on his jacket. And I remember seeing the table was melted, but he was still fused in the chair and that elevator bank was melted, so I imagine the jet fuel must have blown right down the elevator shaft and I guess caught the security guard at a table, I guess at some type of checkpoint.

We figured by the time we got to the fifth or sixth floor, that’s when the south tower was hit. I had no idea the south tower was hit, and I don’t think that Chief Jonas – Captain Jonas at the time – or Lieutenant Foti knew at that point either. I remember the whole north tower literally vibrated. The only way I can explain it is if you were at the edge of a subway platform and the train was coming in, you felt that wind and the sound, but with an added effect like the floor vibrated. Everybody just cringed and really was not sure what was going on. I just assumed that it was something above us. I had no idea that the south tower was hit.

From the sixth floor, we went to the 12th. At the 12th floor there was a bottleneck of civilians still evacuating the tower. We also needed a little rest from the climb up. Lieutenant Foti had us take the people from the B staircase and lead them over to the A staircase because we wanted to clear the B staircase for us. He wanted to make the A the evacuation staircase. We took our gear, our tanks and everything off, tried to cool down, and then we just led people over to the A staircase. It was a distance, I would say 30, 40 feet.

Then from that point we proceeded up and we went up to as far as the 25th floor. When we got to the 25th floor, it was that same effect, like being on the subway platform, but you could tell like that something was really wrong because we heard windows blowing out on our floor. I remember looking at the top of the door, it crimped in. I remember looking at it and going oh, man, that can’t be structurally good, it was almost like at that moment the door wanted to get sucked out, actually get blown out of the building.

That was the first time also that we encountered a smoke condition. We had to force open the door on the 25th floor from the B staircase. It was crushed and we had to force it open to get onto the floor just to see what was going on. There was a very decent smoke condition. You could stay low enough and be all right, but it was to the point if you stayed in there for a while, you’re going to have to mask up.

At that point, 6 Truck came down from 27 to 25. I remember Captain Jonas and two other firefighters came running back into the B stairway. It was us, 1 Truck, a couple of other companies – 9 Engine, 7 Engine. And I remember him saying, oh my God, the second tower is down, if that can come down, being that this is burning longer than the south tower, we definitely have to get out of the north tower now.

We got a rush of air just flying out of the north tower, it was almost like you were getting wind in there, just whoosh, it came rushing out. At that point, Captain Jonas came running back in and said the south tower’s down. I don’t know how he did it. He was as calm as a cucumber, but he was saying we’ve got to start getting out of here now. He went up a couple of floors and made sure that he notified whoever was above him. He transmitted over the radio what he observed and that we were getting out, and at that point we started our descent. I heard Maydays after the collapse, there were Maydays all over the place.

As we were going down, we were trying to stop and double-check the floors that we got to. We did still encounter some civilians on the 20th floor on the way down. There was one guy downloading stuff off his computer and we just told him you got to go now. He really didn’t want to leave, but we basically forced him out of the building at that point. I would say most of the civilians were out at that point.

We tried to check the floors as quickly as we could. Some floors had smoke conditions on them and some floors didn’t. It was weird. I don’t know if that’s because maybe debris from the tower landed in certain floors and maybe lit certain floors on fire. I don’t know. But there was definitely heavy smoke on one floor and then the next floor you’d go to there would be no smoke.

The lights were out. The emergency lights were on in the north tower at that point. The alarm was going off the whole time we were there. It was a deafening alarm sound to get out.

We got down to the third floor. It was us, it was 9 Engine, 6 Truck and there were about six civilians at that point and one lady, Josephine, who was not ambulatory. She couldn’t walk. We were staying with 6 Truck to help them and a chief told 9 Engine, I want you to take these approximately six other people and get them out and I’ll stay with 6 Truck. We didn’t want to leave, but that’s what we were told, so we did it.

We got down to the lobby and my first thought was when we did encounter Josephine and the six other people that looked like they could walk, our first thought was why the hell are you still in the building? And one of the women told me we can’t go down there, there’s smoke and we can’t get out. So I said oh, what the heck is this now? Then we took them with us down to the lobby and when we got to the lobby, it was nothing but debris, heavy smoke and fire.

I masked up. Lieutenant Foti said to me and Sean O’Sullivan, see if you can still find the way we came in. So we had our masks on and we went out, me and Sean together, and we went over one pile of debris and we found one firemen that was definitely deceased at that point. I don’t know who he was or what company he was from. He was in the lobby towards I guess the south tower side. We tried to drag him back with us, but Lieutenant Foti said listen, we can’t do anything for this guy now and we got to get out of here. We didn’t want to, but we had to leave him and we knew we had the other people to try to get out who were still alive.

And with that, Lieutenant Foti knew that if we dropped down into the loading dock area, we could get across a loading dock and come up on Vesey Street because he didn’t want to take these people through this thick smoke condition and sheared steel and rubble. I didn’t think we were going to get out of the lobby. But we dropped down and the smoke went from bad to tolerable and we were able to take the people across the loading dock out towards Vesey Street.

We were out now on Vesey Street and we were going to head back in and make sure that 6 Truck knew that they could come out this way because we knew that they had Josephine. And we turned to walk back down the loading dock and the whole thing just started coming down, the whole north tower. There wasn’t even time to run. I got hit with some huge debris. I still had my mask on at the time and I guess that might have saved me too. I got hit with a huge piece of debris in the back of my air cylinder, which took the wind out of me and knocked me flat on the ground.

At that point, I was ready to curl up. I figured this is it, the whole thing is going to land right on my head. A firefighter, Michael Price in 9 Engine, pulled me under a Port Authority tow truck, one of the big ones that they would tow trucks with. He pulled me under that thing and it just went black as night. I thought I was going to suffocate under this truck now because a force came – I could have sworn the truck, if it didn’t get lifted up, it definitely got moved to the side.

My helmet came blowing right off my head and the next thing I knew there was nothing but debris and dirt and that plume of crushed concrete all around us. You could hardly breathe. I just remember sticking my head in my coat and trying to conserve as much air as I could, figuring I’m probably going to suffocate because I know this whole thing came down around us and I have no idea if anybody’s going to get us out of here.

We stayed in there. We talked to each other for it seemed like an eternity, me, Mike Price. And then eventually it did clear enough that we could see each other. We couldn’t come out of the truck even the same way we came in. We had to back ourselves up out of the truck. I remember the whole top of the tow truck looked like somebody took a can opener and just peeled it right off. Maybe 10 feet from the truck was the biggest piece of steel I-beam I’ve every seen, and there was a dead Port Authority cop right there. We tried to get his body away from the steel beam, but we weren’t moving the steel beam.

Maybe 30 minutes went by by the time the company found each other. At that point, we definitely knew that 6 Truck, if they were alive, they were probably still stuck in there somehow. Lieutenant Foti said let’s just try to find all our guys first and let people know where 6 Truck is because we knew we probably couldn’t get to them by ourselves. We had no tools or anything.

Then we heard a Mayday from 6 Truck – we couldn’t believe they were still alive and we knew that we had a shot to go back in and get them at this point. We got back to where Engine 9 was, the satellite and 6 Truck was. Off-duty members from 6 Truck and 9 Engine were there now.

I remember my father was on the radio trying to locate me because he came with my uncle on the relocation. One of the lieutenants, Lieutenant Chin from 9 Engine, told me your father’s over by the subway, just go tell him that you’re alive. So I ran over there and then the first thing he did when he got me is he said do you remember how you got back in, you know, how you got out because we can get back in that way.

Lieutenant Foti and me and a couple of other firemen from other companies, in the dirt we drew the best way we thought to get in there, we made a little map in the dirt. We were trying to figure out if we went by the loading dock, we knew that we could get up to that B stairway again. And that’s what we did.

It was pretty big down there. It was huge. And there were trucks on fire down there – the trucks were roaring. There was a good smoke condition.

We wound up getting hose off of another engine company. There was a building across the street on Vesey Street. We hooked up to a standpipe there and we ran a hose out because we needed to extinguish the truck fires in the subbasement because that was really just black smoke.

So we stretched a line from there, put out the truck fires, which cleared up the visibility pretty good, but then we could see that there was no way to get from the subbasement any more into the B stairway. It was just completely destroyed, caved in, rubble, everything.

We could still hear them talking and I said we’re never going to get to these guys, there’s no way we can get anything to get up there. It was completely sealed. It was like they were entombed. We stayed in there trying to figure things out. Other supervisors came at that point, other chiefs, and we knew that they were right above us, but we just could not reach them.

We stayed in there as long as we could and then there were other collapses starting now – small debris started coming down all around us. And that’s when my father said that’s it, we got to get out of here now, so we backed out. And thank God, at the same time, that’s when 6 Truck radioed that they found a way out. We still really didn’t know where they were. I went back after and realized what they did. They were basically entombed from the top and the bottom, so it was great that they got out. I couldn’t believe that they walked out of there.

As soon as we got back and 6 Truck was out, we went back to trying to get water because now we had all this fire and no water – 9 Engine was completely blown out. It was burnt. It looked like it got hit with a blow torch. All the windows were blown out in it. So that was useless, but believe it or not the satellite – besides some debris on it – was fine in all other aspects.

We took nine lengths of satellite hose down to the water. We hooked up to a fireboat down there and we operated the monitor at that point into the seven-story building in front of Tower 1. It pretty much put that out, reached great. We had good water pressure. We were augmented by another engine company from the water to the satellite. They put another engine company in there which augmented us. And the stream was even good enough to almost reach Tower 7. And then what happened was, we heard this rumbling sound and my father pulled us all back and then with that Tower 7 came down. We were still operating the satellite at that point. We ran. It really didn’t come up to where the satellite was, but it came close enough.

At that point, they lined up all the firemen on Vesey Street west of West Street down towards the water. Then they said all the firemen on one side, all the officers on another. And they had a meeting, all the chiefs, and then chiefs came over and grabbed an officer and they teamed the officer up with five firemen.

And 6 Truck all went to the hospital after that. They had to be treated. But 9 Engine, the off-duty members and the on-duty members, and the off-duty members of 6 Truck, we stayed together and we just stayed there trying to pull people out.

Me with only two years on this job, I just feel like I was so naive going in there because I had no idea what I was really walking into. I looked up and tried to get things into focus, but there was so much going on. The bodies – it was overwhelming.

At one point in the B stairway, there were still civilians coming down and we were going up, and I couldn’t believe how small the stairways were. I thought in the Trade Center, you’d have these huge stairways that you could fit a truck or up there or something, but you couldn’t. Every time a civilian came down, with the rollups and whatever extra tools you were carrying, you always had to turn to the side so they could pass you, and a lot of them needed help down so you would put your stuff down and help them down to a floor or two to another fireman, and then you’d go back, try to catch up with your company and make the walk up.

When we stopped on the 12th floor and moved, there was like a mass of civilians coming down now. Now, when we moved them over to the A stairway out of the B stairway, that definitely helped because after that point it flowed for us going up because there were no more civilians at that point coming down. And it had to definitely help the civilians get out of the building faster. [..]

http://www.firehouse.com/terrorist/911/magazine/gz/blaich.html

Staircase evacuation

Img: http://www.americanhistory.si.edu/september11/images/medium/62_115.jpg URL: http://www.americanhistory.si.edu/september11/collection/record.asp?ID=62 URL2: http://letsrollforums.com/911-world-trade-center-t16686p20.html Caption: Stairway evacuation, north tower, World Trade Center. Photo by John Labriola.

The building occupants file downstairs as firefighters head up the stairwell in the World Trade Center.

GZ Workers begin to search in the mall in first subbasement level.
(photo filed 9/19/01) Source

Comment: Note the well-preserved basement level. Pockets of air and space within the basement and subbasement levels allowed people like the Stairway “B” survivors escape death. The basement/subbasement also provided shielding against the effects of the nuclear attack.

http://www.photolibrary.fema.gov/photodata/original/5347.jpg

http://drjudywood.com/articles/DEW/StarWarsBeam4.html

GZ workers descend into the subbasements below WTC2.

Comment: it was caverns like this one that allowed people to survive the nuclear attack. The mass also helped shield people from the effects of the nuclear attack.

http://www.photolibrary.fema.gov/photodata/original/3946.jpg

http://drjudywood.com/articles/DEW/StarWarsBeam4.html

http://glasstone.blogspot.com/

Decontamination of fallout

In non-quantitative outline, if the fallout is in soluble form (as for a detonation involving proximity to sea water), then the problems are at their worse because many of the fission products are present in the ionic solution and become chemically bound to surfaces. If the detonation occurs over a typical land surface which is about 50% or more silicate (e.g., typical sand), then the decontamination is easier because most of the activity is insoluble (trapped in the solidified spheres of glass). Dry fallout can be decontaminated by a range of activities from flushing it down storm drains with water hosing, to using normal mechanical street sweepers. Inclined roofs do not retain large fallout particles efficiently, simplifying decontamination of buildings. The efficiency of decontamination depends strongly upon the total quantity of fallout taken up into the mushroom cloud and stem, which is typically about 1% of the mass of material ejected from the crater in a surface burst, typically 300-700 tons of fallout per kiloton of yield.

For example, when decontaminating land surface burst fallout from portland cement concrete by fire-hosing, the fallout protection factor afforded by this decontamination is 25 for a fallout deposit of 100 g/m², 50 for 330 g/m², and 125 for 1,000 grams/m². These deposits of 100, 330, and 1,000 g/m² typically correspond to 1 hour reference gamma exposure rates of 300, 1,000 and 3,000 R/hr respectively. Hence the best efficiency for decontamination occurs where the danger is most severe. Where the fallout is very light, decontamination is less efficient because the smaller number of smaller sized fallout particles involved tend to quickly get caught or trapped in small crevices, cracks or surface irregularities, where water flushing is less effective. (These data are from Radiological Recovery of Fixed Military Installations, U.S. Army Chemical Corps Technical Manual TM-3-225 (1958). This fire-hosing method uses 4-cm diameter hoses, each crewed by 2-4 people, with 100 gallons/minute of water at 5 atmospheres pressure to decontaminate 700 m²/hour; fallout is flushed into underground drains to decay, so the radiation is safely absorbed below ground level.)

Nevada nuclear weapon test experience: dry fallout on paved areas 0.6-1.6 km from nuclear tests Sugar and Uncle in 1951 was successfully removed: ‘High-pressure water hosing was found to be the most rapid and effective … None of the tested procedures [including dry sweeping and vacuum cleaning] resulted in significant contamination of the operator’s protective clothing.’ – J.C. Maloney, Decontamination of Paved Areas (U.S. test report WT-400, 1952, Ch. 5). The contamination per unit area of vertical walls was only 0.3-10% of that on horizontal ground and roofs (Jangle Project 6.2, WT-400, 1952).
R.T. Graveson reported that fallout on the roof of a house at the Nevada test site was decontaminated by 5 cm of natural rainfall, causing in a 15-fold reduction of the gamma dose rate indoors (U.S. report NYO-4714, 1956). F.T. Underwood of the U.K. Home Office reported fallout adherence: over 90% of fallout particles exceeding 1 mm in diameter rolled or bounced off roofs with a 45-degree slope. But 95% of fallout particles less than 0.2 mm in diameter adhered to a 45-degree ceramic tiled roof. For a 45-degree roof slope, 90% of the retained fallout on 0.13 cm thick PVC (glued to the roof) was removed by just 1 litre/m² (0.1 cm of rain). Without PVC, fallout grains roll into, and lodge in, small pits and crevices (reports CD/SA-103 and CD/SA-125, 1961-5).

Experience of fallout in unprotected civilian areas of America was obtained after four 1953 Nevada shots on 91-m high towers: Annie, Badger, Simon, and Harry. The 1957 U.S. Congressional Hearings, The Nature of Radioactive Fallout and Its Effects on Man, pp. 231-2, show that Nevada staff washed vehicles on highways where the infinite time dose exceeded 5 R (using the t^-1.2 formula, D_infinity = 5RT, where R is dose rate at start time T after burst).

The highest public fallout is listed as being 97 km downwind from the Harry test, where the peak outside dose rate was 1 R/hr on Highway 93 at 2 hours after burst: ‘The ratio of dose rate readings on the outside of the car to inside varied from unity to about 4/1 … One bus read 250 mR/hr outside and an average of 100 mR/hr inside with a high inside reading over the rear seat of 140 mR/hr at H + 8.75 hours.’ At St George, Utah (210 km downwind), the Harry fallout reached 0.42 R/hr at 3.75 hours with a measured peak air concentration at the same time of 154,000 Bq/m³.. The 4,500 inhabitants were requested by radio to stay indoors for two hours to avert skin contact.

Decontamination of Farms: roads, paved areas, building surfaces, vehicles, aircraft and ships can be decontaminated by water hosing. For fields, single-pass deep-ploughing to 20-25 cm depth (3,250 m²/hour using an old 125 horse-power tractor with a 3-share plough) reduced the above-ground fallout gamma radiation by an average factor of 6.7 (U.S. Army Chemical Corps technical manual TM-3-225, 1958).

City decontamination: Britain planned decontamination by fire-hosing residential areas where the 1-hour reference gamma dose rate was 500-3,000 R/hr (Home Office report SA/PR-97, 1965, originally secret). At lower levels, there are few casualties indoors anyway (200 R producing a casualty), while higher levels expose decontamination crews to excessive doses even 5 days after detonation, so evacuation is then a better option. Decontamination is feasible at 1-5 days after detonation, when a 1-hour outdoor dose rate of 500-3,000 R/hr has decayed to 10 R/hr. Decontamination crews restricted to areas below 10 R/hr cannot get more than 10 x 8 = 80 R in an 8 hour shift.

The three key stages during radiological recovery after first aid, rescue and fire spread prevention: (1) evacuation of people with inadequate shielding from heavy fallout areas; (2) sheltering for 1-5 days in the part of the house furthest from the roof and outside walls, with as much mass around the ‘inner refuge’ as possible, and staying indoors as much as possible for a month, and (3) outdoor decontamination.

Internal fallout contamination of humans: inhalation of fallout in Britain from the American and Russian tests of 1958 peaked at 3.7-Bq/day of beta emitters between January-June 1959, when the total fallout intake from food was 120-Bq/day. The maximum concentration of plutonium in the air was lower than natural radon-222. For Sr-90, the intake in Britain in 1959 was 0.33-Bq/day from food, 0.015-Bq/day inhalation, and tap water contained 0.016-Bq/litre (Medical Research Council, Second Report, 1960).

After Britain’s Windscale nuclear accident of October 1957, the concentration of I-131 in contaminated milk was 500 times higher than that in tap water from reservoirs in the same areas. Ion-exchange interaction of soluble nuclides with soil or rock slows down the migration of dissolved radioactivity in groundwater and surface rain run-off. It was 30 days after the Chernobyl reactor accident in 1986 when tap water, obtained from a river in the nearby city of Kiev, attained a peak activity of 370-Bq/litre, which returned to natural background within a year. The 1957 U.S. Congressional Hearings on fallout, p. 233, shows that the maximum contamination of tap water 3 days after any 1953 Nevada nuclear test was only 44-Bq/litre (at Bunkerville, Nevada, where the gamma outdoor infinity dose was 7 R), compared to 3,200-Bq/litre in an irrigation canal.

‘A number of factors make large-scale decontamination useful in urban areas. Much of the area between buildings is paved and, thus, readily cleaned using motorized flushers and sweepers, which are usually available. If, in addition, the roofs are decontaminated by high-pressure hosing, it may be possible to make entire buildings habitable fairly soon, even if the fallout has been very heavy.’ – Dr Frederick P. Cowan and Charles B. Meinhold, Decontamination, Chapter 10, pp. 225-40 in Dr Eugene P. Wigner (editor), Survival and the Bomb, Indiana University Press, Bloomington, 1969.

———————————————————————

Measurement of effects – 2kt and 3kt size detonations and damage zones

Impact of fizzle-yield explosion

(Area of complete destruction)

Source: Ted Postol, MIT

Glaser PDF

lecture_maxburst

http://www.ippnw-students.org/Target/newyork.html

Decontamination – washing stations

http://www.armageddononline.org/forums/printthread.php?t=7901

Decontamination at the Pentagon

http://www.armageddononline.org/forums/printthread.php?t=7901

http://911speak.com/WTC/wtc.htm

The aftermath of the World Trade Center terrorist attack created environmental cross-contamination and track-out problems similar to those faced today by most landfills, mines and quarries.

Trucks leaving the Ground Zero site as part of the debris removal operation carried asbestos contamination and dirt, and were spreading it all over New York City streets.

The EPA and the environmental contractors doing the clean-up work turned to InterClean to provide tire wash stations for the site.

The real engineering and manufacturing challenge was to complete the task within the allocated time frame. The tire wash systems were due to be operational within three weeks after the first contact by the EPA. This included setting up the buildings with total turnkey installations.

The ground zero tire and wheel wash systems used standard InterClean components and operated in similar fashion to the new InterClean Tire Wash System. The ground zero tire washers were built and installed in record time and washed vehicles in record numbers, over 2,000 each day.

http://www.interclean.com/InterClean/List/wtc/index.htm

Compare before and after

ground_zero_streets_17

Street cleaning began on 9/11.

Trucks bringing in dirt

IMG: https://apunked.files.wordpress.com/2017/02/010927_5644cb.jpg URL: http://drjudywood.com/articles/dirt/dirt3.html

More soil pictures

http://home.hiwaay.net/%7Elangford/wtc/

Lack of fireball and flash

Nevada underground nuclear test – movie

Click on image to open video

Watch the explosion at 1:19 minute. Note the explosion lacks a fireball or a flash as it’s underground.

http://www.dailymotion.com/skyblue09/video/5226459

http://video.google.co.uk/videoplay?docid=1870730456324813920&q=underground+nuke+test

http://www.armageddononline.org/forums/printthread.php?t=7901&pp=25&page=2

Plowshare testing

Although underground testing was the rule after August 1963, it is not exactly true that no radioactivity was released into the atmosphere after that date. First, there were five Plowshare cratering tests conducted underground, but designed to breach the surface (see below). These released a total of 984 kilocuries of I-131 (radioiodine) into the atmosphere. Containment failures for for a few dozen other tests that were supposed to be entirely underground released another 123 kilocuries (two-thirds of this was due to Baneberry, with Des Moines, and Bandicoot accounting for nearly all of the rest). For comparison, Trinity released about 3200 kilocuries of radioiodine.

http://nuclearweaponarchive.org/Usa/Tests/Nts.html

Calculations of Effects

5.1 Overview of Immediate Effects

The equations below provide approximate scaling laws for relating the destructive radius of each effect with yield:

r_thermal = Y^0.41 * constant_th
r_blast = Y^0.33 * constant_bl
r_radiation = Y^0.19 * constant_rad

If Y is in multiples (or fractions) of 2.5 kt, then the result is in km (and all the constants equal one). This is based on thermal radiation just sufficient to cause 3rd degree burns (8 calories/cm^2); a 4.6 psi blast overpressure (and optimum burst height); and a 500 rem radiation dose.

These scaling laws show that the effects of thermal radiation grow rapidly with yield (relative to blast), while those of radiation rapidly decline.

In the Hiroshima attack (bomb yield approx. 15 kt) casualties (including fatalities) were seen from all three causes. Burns (including those caused by the ensuing fire storm) were the most prevalent serious injury (two thirds of those who died the first day were burned), and occurred at the greatest range. Blast and burn injuries were both found in 60-70% of all survivors. People close enough to suffer significant radiation illness were well inside the lethal effects radius for blast and flash burns, as a result only 30% of injured survivors showed radiation illness. Many of these people were sheltered from burns and blast and thus escaped their main effects. Even so, most victims with radiation illness also had blast injuries or burns as well.

With yields in the range of hundreds of kilotons or greater (typical for strategic warheads) immediate radiation injury becomes insignificant. Dangerous radiation levels only exist so close to the explosion that surviving the blast is impossible. On the other hand, fatal burns can be inflicted well beyond the range of substantial blast damage. A 20 megaton bomb can cause potentially fatal third degree burns at a range of 40 km, where the blast can do little more than break windows and cause superficial cuts.

It should be noted that the atomic bombings of Hiroshima and Nagasaki caused fatality rates were ONE TO TWO ORDERS OF MAGNITUDE higher than the rates in conventional fire raids on other Japanese cities. Eventually on the order of 200,000 fatalities, which is about one-quarter of all Japanese bombing deaths, occurred in these two cities with a combined population of less than 500,000. This is due to the fact that the bombs inflicted damage on people and buildings virtually instantaneously and without warning, and did so with the combined effects of flash, blast, and radiation. Widespread fatal injuries were thus inflicted instantly, and the many more people were incapacitated and thus unable to escape the rapidly developing fires in the suddenly ruined cities. Fire raids in comparison, inflicted few immediate or direct casualties; and a couple of hours elapsed from the raid’s beginning to the time when conflagrations became general, during which time the population could flee.

http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html

Underground burst

An underground burst (nuclear ‘earth penetrator’ against hardened targets)
‘In this case a large part of the heat radiation and the immediate nuclear radiation is absorbed in the crater [photos of Nevada 1951 shallow underground nuclear test Uncle and Nevada 1955 deeper underground nuclear test Ess shown] produced by the explosion, and the surrounding buildings provide considerable shielding against the remainder.

‘Much of the blast energy goes into the production of a shock wave in the earth, a feature which is absent from the air burst and less important when the burst is on or near the ground. This shock will cause damage to underground structures and services as well as to buildings above ground, but the power of the blast wave in the air above is reduced.

‘A greater proportion of the radioactivity is trapped in the debris of the crater, mingling with the material which spills out around the crater and immediately downwind. This gives rise to a serious but more localised residual radiation hazard; the radioactive fall-out beyond is less widely distributed.

http://www.glasstone.blogspot.com/

Carwashing stations

A vehicle wash station at Ground Zero. No vehicles were permitted offsite without first being washed.

http://911research.wtc7.net/cache/wtc/analysis/asse_groundzero1.htm

Dirty bombs

Hand-held radiation sensor

Caption: A U.S. Customs and Border Protection officer displays a radiation detector showing a level-nine reading of radiation, as passengers arrive at Miami International airport on Jan. 26. With the rising use of radioisotopes in medicine and the growing use of radiation detectors in a security-conscious nation, patients are triggering alarms in places where they may not even realize they’re being scanned

http://www.msnbc.msn.com/id/16869630/

Thermal shielding

The perimeter walls of the World Trade Center Twin Towers

The buildings used high-strength, load-bearing perimeter steel columns called Vierendeel trusses that were spaced closely together to form a strong, rigid wall structure. There were 59 perimeter columns, narrowly spaced, on each side of the buildings. [..] The perimeter structure was constructed with extensive use of prefabricated modular pieces, which consisted of three columns, three stories tall, connected by spandrel plates. The perimeter columns had a square cross section, 14 inches (36 cm) on a side, and were constructed of welded steel plate. [..] The spandrel plates were welded to the columns to create the modular pieces off-site at the fabrication shop. The modular pieces were typically 52 inches (1.3 m) deep, and extended for two full floors and half of two more floors. [..]

http://en.wikipedia.org/wiki/Construction_of_the_World_Trade_Center

Img: http://3.bp.blogspot.com/_A1mImmnPZvE/RhopqBxqT1I/AAAAAAAAABU/ORKvj8QjRk0/s400/Image1.gif

URL: http://911-engineers.blogspot.com/2007/04/collapse-of-world-trade-center-twin.html

Caption: Both towers were tube-like, and the majority of their support came from exterior columns. There was also a cluster of columns in the center of the building connected to the exterior columns by floor trusses.

Img: http://911research.wtc7.net/mirrors/guardian2/wtc/wall-column.gif

URL: http://letsrollforums.com/world-trade-center-architectural-t21523.html?p=179602

Caption: Diagram (above): Horizontal section through an external column with window frame connection

The external framework was erected using prefabricated three-storey units, each comprising columns interconnected by spandrel panels. These units, ranging in weight from 22.3 to 6.0 tonnes, were fitted together, alternately staggered in one storey heights, and spliced with high-strength friction-grip bolts. The external cladding to columns and spandrels consists of aluminium sheet. The window openings, 1.98 x 0.48 m, are infilled with bronze-tinted solar-heat rejecting glass fitted into aluminium frames and sealed with Neoprene gaskets.

Img: http://www.serendipity.li/wot/wtc_dem82/col-dimensions.gif

URL: http://www.serendipity.li/wot/wtc_demolition.htm

Caption: The numbers in the figure denote: 36 – the steel column 38 and 39 – fire resistant plaster 40 – aluminum facade 42 – window glass 43 – the window frame.

Img: http://static.howstuffworks.com/gif/wtc-tube.jpg

URL: http://science.howstuffworks.com/engineering/structural/wtc.htm/printable

Caption: The outer box, measuring 208 feet by 208 feet (63×63 m), was made up of 14-inch (36-cm) wide steel columns, 59 per building face, spaced just over 3 feet (1 m) apart. On every floor above the plaza level, the spaces between the columns housed 22-inch (56-cm) windows. Yamasaki, who had a pronounced fear of heights, felt that the small windows made the building feel more secure. The columns were covered with aluminum, giving the towers a distinctive silver color.

Img: http://serendipity.911review.org/wot/wtc_ch2a/fig-2-3.jpe

URL: http://serendipity.911review.org/wot/wtc_ch2.htm

Caption:

The buildings’ signature architectural design feature was the vertical fenestration, the predominant element of which was a series of closely spaced built-up box columns. At typical floors, a total of 59 of these perimeter columns were present along each of the flat faces of the building. These columns were built up by welding four plates together to form an approximately 14-inch square section, spaced at 3 feet 4 inches on center. Adjacent perimeter columns were interconnected at each floor level by deep spandrel plates, typically 52 inches in depth. In alternate stories, an additional column was present at the center of each of the chamfered building corners. The resulting configuration of closely spaced columns and deep spandrels created a perforated steel bearing-wall frame system that extended continuously around the building perimeter.

Figure [..] presents a partial elevation of this exterior wall at typical building floors. Construction of the perimeter-wall frame made extensive use of modular shop prefabrication. In general, each exterior wall module consisted of three columns, three stories tall, interconnected by the spandrel plates, using all-welded construction. Cap plates were provided at the tops and bottoms of each column, to permit bolted connection to the modules above and below. Access holes were provided at the inside face of the columns for attaching high-strength bolted connections. Connection strength varied throughout the building, ranging from four bolts at upper stories to six bolts at lower stories. Near the building base, supplemental welds were also utilized.

Side joints of adjacent modules consisted of high-strength bolted shear connections between the spandrels at mid-span. Except at the base of the structures and at mechanical floors (Figure 2-8 shows one of these mechanical floors. Note that all the perimeter wall columns are joined/spliced at this one level.) horizontal splices between modules were staggered in elevation so that not more than one third of the units were spliced in any one story. Where the units were all spliced at a common level, supplemental welds were used to improve the strength of these connections. Figure 2-3 illustrates the construction of typical modules and their interconnection. At the building base, adjacent sets of three columns tapered to form a single massive column, in a fork-like formation, shown in Figure 2-4.

The stiffness of the spandrel plates, created by the combined effects of the short spans and significant depth created a structural system that was stiff both laterally and vertically. Under the effects of lateral wind loading, the buildings essentially behaved as cantilevered hollow structural tubes with perforated walls. In each building, the windward wall acted as a tension flange for the tube while the leeward wall acted as a compression flange. The side walls acted as the webs of the tube, and transferred shear between the windward and leeward walls through Vierendeel action (Figure 2-5).

Img: http://www.bollyn.com/public/column_and_spandrel_const.jpg

URL: http://www.rebelnews.org/opinion/terror/612342-an-analysis-of-the-missile-of-flight-175

Caption: The 14-inch box columns and 52-inch spandrel plates, the 4-inch thick concrete floors and their steel pans and trusses, and the massive core columns would have prevented the wreckage of the plane from passing through the building.

Img: http://911research.wtc7.net/wtc/evidence/photos/docs/constr07/wtc_groundlevel_perimeter.jpg

URL: http://911research.wtc7.net/wtc/evidence/photos/wtccons3.html

Caption: Construction of the Twin Towers showing the box columns and spandrels of the perimeter walls.

Img: http://4.bp.blogspot.com/_OfpZQm4cpao/TM5Nk1FwpnI/AAAAAAAACLg/hsCZR5OHV-A/s400/WTC_Twin_Tower_steel_perimeter_columns.jpg

URL: http://starkravingviking.blogspot.com/2010/11/did-fbi-bomb-world-trade-center-in-1993.html

Img: http://heiwaco.tripod.com/WTC1floorconnection.jpg

URL: http://heiwaco.tripod.com/nist0.htm

Img: http://911research.wtc7.net/wtc/evidence/photos/docs/wtcmemorium/trident5.jpg

URL: http://911research.wtc7.net/wtc/evidence/photos/wtccons4.html

Img: http://commons.wikimedia.org/wiki/File:World_Trade_Center_lobby,_08-19-2000.png

URL: http://www.newworldencyclopedia.org/entry/World_Trade_Center

Caption: Lobby of World Trade Center tower. View of tridents from inside.

Img: http://www.atpm.com/10.08/images/02-world-trade-center.gif

URL: http://www.usmessageboard.com/conspiracy-theories/85840-fema-deceives-nation-about-twin-towers-core-19.html

Radiation Protection Factor

[T]he tenth-value thickness, in inches, for steel is 3.3; for concrete, 11; for earth, 16; for water, 24; for wood, 38. That means that where you have those thicknesses you’ll have only 1/10th as much gamma radiation pass through with that barrier material.

http://www.radshelters4u.com/index3.htm#a2

The Bathtub

The twin towers were part of a seven-building complex designed by architect Minoru Yamasaki that covers eight city blocks. An 800 x 400-ft foundation box, 65-ft-deep and with 3-ft-thick retaining walls, is under more than half the complex, including the twin towers and the adjacent hotel. The complex was completed in phases beginning in 1970. The 1.8-million-sq-ft Seven World Trade Center, constructed in the mid-80s, also had a steel moment frame from the seventh story up.

http://www.ussartf.org/world_trade_center_disaster.htm

Dimensions

Areas and volume (per tower)

gross area: 418,000 m2
area on plan: 4,032 m2
effective floor area: 319,000 m2
volume: 1,754,000 m3

Quantities of steel (structural steelwork in one tower)

total: 78,000 tonnes
per square meter gross area: 166.6 kg
per cubic meter: 44.5 kg
per square meter effective floor area: 244.5 kg

References

Architectural Forum, 4/1 964. p. 119.
Engineering News-Record. 9/1964. p. 36; 11/1971.
Der Stahlbau, 11/1964. p. 350; 4/1970. p. 123.
Der Baningenleur. 9/1965. p.373:11/1967, p. 421.
Bauwelt. 32/1 966. p. 909.
Acier-Stahl-Steel. 12/1966, p. 556:6/1970. p. 273.

http://letsrollforums.com/world-trade-center-architectural-t21523.html?p=179602

Residual radiation at the World Trade Center site

Report by the Manhattan Engineer District, June 29, 1945

The following are the main conclusions which were reached after thorough examination of the effects of the bombs dropped on Hiroshima and Nagasaki:

No harmful amounts of persistent radioactivity were present after the explosions as determined by:

Measurements of the intensity of radioactivity at the time of the investigation; and

Failure to find any clinical evidence of persons harmed by persistent radioactivity.

http://www.atomicarchive.com/Docs/MED/med_chp4.shtml – The Atomic Bombings of Hiroshima and Nagasaki by The Manhattan Engineer District, June 29, 1946

Are Hiroshima and Nagasaki still radioactive?

The practical answer is, “No.”

Doses from residual radioactivity in both cities are now far below the annual background dose (0.001-0.003 Sv); hence, there are no detectable effects on human health. Radioactivity was over 90% gone by one week after the bombings and was less than the background level by one year.

People often ask, “If uranium and plutonium pose a potential hazard in nuclear waste sites and were present at dangerous levels in the environment following the Chernobyl nuclear accident, why aren’t Hiroshima and Nagasaki still uninhabitable?”

There are two ways residual radioactivity is produced from an atomic blast. The first is due to fallout of the fission products or the nuclear material itself–uranium or plutonium (uranium was used for the Hiroshima bomb whereas plutonium was used for the Nagasaki bomb)–that contaminate the ground. Similar ground contamination occurred as a consequence of the Chernobyl accident, but on a much larger scale (click here for more-detailed explanation). The second way residual radioactivity is produced is by neutron irradiation of soil or buildings (neutron activation), causing non-radioactive materials to become radioactive.

Fallout. The Hiroshima and Nagasaki bombs exploded at altitudes of 600 meters and 503 meters, respectively, then formed huge fireballs that rose with the ascending air currents. About 10% of the nuclear material in the bombs underwent fission; the remaining 90% rose in the stratosphere with the fireball.

Subsequently, the material cooled down and some of it started to fall with rain (black rain) in the Hiroshima and Nagasaki areas, but probably most of the remaining uranium or plutonium was dispersed widely in the atmosphere. Because of the wind, the rain did not fall directly on the hypocenters but rather in the northwest region (Koi, Takasu area) of Hiroshima and the eastern region (Nishiyama area) of Nagasaki.

The maximum estimates of dose due to fallout are 0.01-0.03 Gy in Hiroshima and 0.2-0.4 Gy in Nagasaki. The corresponding doses at the hypocenters are believed to be only about 1/10 of these values.

Nowadays, the radioactivity is so miniscule that it is difficult to distinguish from trace amounts (including plutonium) of radioactivity caused by worldwide fallout from atmospheric (as opposed to underground) atomic-bomb tests that were conducted around the world in past decades, particularly in the 1950s and 1960s.

Neutron activation. Neutrons comprised 10% or less of the A-bomb radiation, whereas gamma rays comprised the majority of A-bomb radiation. Neutrons cause ordinary, non-radioactive materials to become radioactive, but gamma rays do not. The bombs were detonated far above ground, so neutron induction of radioactivity on the ground did not produce the degree of contamination people associate with nuclear test sites (Nevada test site in Southwest U.S., Maralinga test site in South Australia, Bikini and Mururoa Atolls, etc.).

Past investigations suggested that the maximum cumulative dose at the hypocenter from immediately after the bombing until today is 0.8 Gy in Hiroshima and 0.3-0.4 Gy in Nagasaki. When the distance is 0.5 km or 1.0 km from the hypocenter, the estimates are about 1/10 and 1/100 of the value at the hypocenter, respectively. The induced radioactivity decayed very quickly with time. In fact, nearly 80% of the above-mentioned doses were released within a day, about 10% between days 2 and 5, and the remaining 10% from day 6 afterward. Considering the extensive fires near the hypocenters that prevented people from entering until the following day, it seems unlikely that any person received over 20% of the above-mentioned dose, i.e., 0.16 Gy in Hiroshima and 0.06-0.08 Gy in Nagasaki.

As for Hiroshima and Nagasaki proper, the longest-lasting induced radionuclide that occurred in amounts sufficient to cause concern was cesium-134 (with a half-life of about 2 years). Most of the induced radioactivities from various radionuclides decayed very quickly so that it now takes considerable time and effort to measure it using highly sensitive equipment. Despite such miniscule levels, measurements of residual radioactivity using recently developed ultra-sensitive techniques have been utilized to estimate neutron doses released from the bombs and have formed part of the basis of the latest atomic-bomb dosimetry (DS02).

http://www.rerf.or.jp/general/qa_e/qa12.html – Radiation Effects Research Foundation

____________________________________

Shielding

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Ironic FEMA publication

Home Expedient & Effective Sheltering Options You Could Do Very Quickly…

Protection Factor (PF)

Expedient blast shelters

Hiroshima earth shelter

Shelters that survived intact

SHIELDING and SHELTER

Decontamination

Washing of the steel to decontaminate it of radioactivity

Steel sent to China

Shielding provided by smog and cloud cover

Calculation of Yield

Map of damage and distance from the hypocenter

Summary of the effects

Earthquake

Earthquake trench in Liberty Street

Bunker buster in action

Nuclear bunker buster

Underground detonations limit collateral damage

The B61-11 Nuclear Bomb

Containment

Crater

Containment

Building construction – inner core – Chapter 2

Concrete Core

North Tower core

Core – Chapter 2

External wall construction – box columns and spandrels

Bathtub Construction

Subsurface burst and effects

Nuclear bunker buster

Richter magnitude and TNT-equivalent seismic energy yield

Summary of Impact of 1 KT Nuclear Blast

Formulae to calculate effects

Some sample computations using the cubic root scaling rules for size of blast and yield

Radii of effects of nuclear weapons

Nuclear effects calculator

Another Nuclear weapons effects calculator

How much is 10 kilotons?

Staircase B Survivors

Engine 9 Fireman’s Story

Measurement of effects – 2kt and 3kt size detonations and damage zones

Impact of fizzle-yield explosion

(Area of complete destruction)

Decontamination – washing stations

Compare before and after

Trucks bringing in dirt

More soil pictures

Lack of fireball and flash

Nevada underground nuclear test – movie

Plowshare testing

Calculations of Effects

Underground burst

Carwashing stations

Dirty bombs

Hand-held radiation sensor

The perimeter walls of the World Trade Center Twin Towers

The Bathtub

Dimensions

Residual radiation at the World Trade Center site

Are Hiroshima and Nagasaki still radioactive?

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