Oklahoma City Bombing: Expert Analysis

Autarchic 2011/04/19 20:00:20
Related Topics: Congress, Fuel
by William F. Jasper

For most of us, the first images of the enormous damage done to Oklahoma City's Alfred P. Murrah Federal Building in the April 19th bombing were overwhelming. Besides the terrible toll of death and suffering, the news photos and live video recordings of the physical destruction of the blast to the building itself showed a devastation completely beyond the ken of Americans unaccustomed to the ravages of war and terrorism. Lacking mental reference points to frame the enormity of this destruction, and recoiling from the barbarity of the deed, our primary reactions were visceral, emotional.

Beyond Emotion

However, for many men accustomed by profession to dealing with explosives, the aftermath of the explosion brought troubling cerebral reactions as well. When the smoke cleared to reveal the now-familiar gaping cavity, they were faced with severe cognitive dissonance: The reported "facts" did not match observable reality. For Brigadier General Benton K. Partin (USAF, Ret.), the "facts" contradicted not only the laws of physics but a lifetime of experience as well.

As one of the world's foremost experts in both the theoretical and practical applications of explosives technology, General Partin possesses virtually unparalleled qualifications to authoritatively evaluate the public-source information available on the bombing. When we contacted General Partin shortly after the explosion, he expressed very strong misgivings about the official story -- that the horrendous damage to the federal building had been caused solely by the reported truck bomb. Too many facts, he said, "simply just don't add up" to support that convenient explanation. However, unlike other "experts" who were offering instant analyses and publicly speculating about various bombing scenarios, he had a great deal of investigating to do before presenting a definite opinion. After three weeks of intensive examination of the evidence, he was ready. However, a major problem loomed: Authorities were planning to demolish the still-standing remains of the building.

In a letter to Oklahoma Senator Don Nickles, which he personally delivered to the senator's Washington office on May 18th, General Partin appealed for action to delay destruction of the Murrah building until a full, independent forensic examination of the site could be conducted. In that letter, which was also personally delivered to the offices of 23 other senators and some 30 members of the House, the general wrote:

"I am concerned that vital evidence will soon be destroyed with the pending demolition of the Federal Building in Oklahoma City. From all the evidence I have seen in the published material, I can say with a high level of confidence that the damage pattern on the reinforced concrete superstructure could not possibly have been attained from the single truck bomb without supplementing demolition charges at some of the reinforced column bases. The total incompatibility with a single truck bomb lies in the fact that either some of the columns collapsed that should not have collapsed or some of the columns are still standing that should have collapsed and did not."

General Partin offered what he called an "oversimplified analogy" to illustrate his point. The pattern of damage to the reinforced concrete columns was so totally at odds with the laws of physics and explosives experience, he said, that it "would be as irrational or as impossible" as a situation in which a 150 pound man sits in a flimsy chair causing the chair to collapse, while a man weighing 1,500 pounds sits in an identical flimsy chair and it does not collapse.

"To produce the resulting damage pattern on the building," wrote Partin, "there would have to have been an effort with demolition charges at column bases to complement or supplement the truck bomb damage. A careful examination of the collapsed column bases would readily reveal a failure mode produced by a demolition charge. This evidence would be so critical, [that] a separate and independent assessment should be made before a building demolition team destroys the evidence forever."

Sterling Credentials

Another "wacko conspiracy theory"? Absolutely not. What makes General Partin's position so noteworthy and compelling is his methodical, scientific analysis combined with his sterling career and credentials. Twenty-five of his 31 years of active service in the Air Force were involved in intensive research, design, testing, and management of weapons development at all levels. This included extensive hands-on work at the Ballistic Research Laboratories and field testing of all types of explosive devices on a broad spectrum of structures and targets. He served as commander of the Air Force Armament Technology Laboratory and was the first chairman of the joint service Air Munitions Requirements and Development Committee in the Office of the Secretary of Defense. This committee was responsible for the harmonization of air munitions requirements and development for the Army, Navy, Air Force, and Marine Corps.

General Partin is recognized as a long-time guiding force behind our modern precision-guided weapons and related target acquisition, target designation, and guidance systems. He initiated, fought for, and helped get into service many weapons now in our nation's munitions inventory. As the Air Force System Command's Special Assistant for Advanced Weapons, he started the earliest focused energy weapons program in 1957, wrote the first contract for a coherent optical frequency generator (i.e. laser) in 1958, and pushed for development of a functional "Star Wars" missile system decades before it became the hotly debated issue in the 1980s. General Partin was a Command Pilot and Command Missileman, a Distinguished Graduate of the Air War College, a recipient of the Distinguished Service Medal and thrice a recipient of the Legion of Merit. He received a B.S. degree in chemical engineering, an M.S. in aeronautical (armament) engineering, and completed academics for a Ph.D. in operations research and statistics.

In short, General Ben Partin is not just your average "expert," and his reasoned analysis deserves a careful examination, instead of snide dismissal as "just another Elvis sighting" -- a response typical of the media elites and "sophisticated" political savants.

Single-Bomb Problem

"When I first saw the pictures of the truck bomb's asymmetrical damage to the Federal Building in Oklahoma City," Partin wrote in his letter, "my immediate reaction was that the pattern of damage would have been technically impossible without supplementing demolition charges at some of the reinforced concrete column bases (a standard demolition technique)."

Partin then explained some of the basic physics problems associated with the single-truck-bomb scenario: "First, blast through air is a very inefficient energy coupling mechanism against heavy reinforced concrete beams and columns. Second, blast damage potential initially falls off more rapidly than an inverse function of the distance cubed. That is why in conventional weapons development, one seeks accuracy over yield for hard targets. Columns in large buildings are hard targets for blast."

This principle was very well illustrated, he noted, in the bombing of the World Trade Center. In that case, General Partin told The New American, a similar truck bomb blew a large cavity through several floors above and below the bomb but caused very limited lateral damage. "The floor areas directly above and below the bomb were accelerated by the blast force and completely stripped away, but you can see in the published photos [as, for instance, in Time magazine of March 8, 1993] and by the BATF , that the column is still standing there in the middle of the cavity."

"The entire building in Oklahoma City could have been collapsed with relatively small demolition charges against the base of the columns and with even less explosives if linear cavity cutting charges had been used," General Partin wrote in his letter to Senator Nickles. "I know of no way possible to reproduce the apparent building damage without well-placed demolition charges complementing the truck bomb damage." As the final demolition of the Murrah building on May 23rd demonstrated, a very small amount of explosives is required to bring down a building -- if the demolition charges are strategically placed within, or in direct contact with, the key structural points of the building.

Detailed Account

Partin provides a careful look at the Murrah building's structure in the following description and accompanying diagram:

"From published photographs, the basic building structure is three rows of eleven columns each. The four corner columns have external clamshell like structure for air ducts, etc., as revealed in magazine photographs of the damage. If we label the column rows A, B, & C, from front to back, and number the columns 1 through 11 from left to right, then published pictures show columns A2, A3, A4, A5, A6, A7, A8, and B3 collapsed, essentially vertically. The 5-1-95 U.S. News and World Report and other damage photos show a very large re-enforced concrete header at the second floor level of column row A. Much larger columns extend from the header down for the odd numbered columns i.e. A3, A5, A7, A9. The even numbered columns extended down to the header with apparently reinforced concrete joints. The heavy, odd-numbered columns were all accessible from the sidewalk, but collapsed Column B3 is well inside the building. If the truck bomb was not nearest to column A3 then a single truck bomb theory would be even more questionable.

"A rough sketch of the Federal Building and its columns shown [on page 16] has superimposed circles of roughly equal levels of damage potential which drop rapidly (exponentially) as they get further and further away from the truck bomb.* If we consider the damage potential at column A3, the closest column to the truck on the sketch, to be damage potential level one at distance one, then moving out further multiples of that distance, the destructive potential drops off as an exponential function of one over the number of multiples. Therefore at circle '1' you have a decisively destructive force that brought down column A3. At circle '2' the destructive potential is marginal for row A; column A5 came down but the heavier column A1 did not. Inside circle '3' level, column B3 came down; but columns B2 and B4 did not come down. Therefore circle 3 is marginal for the columns in row B which are much smaller than the odd numbered columns in row A. Moreover, the higher numbered columns in row A are seeing more of a lower side-on pressure than column row B.


*NOTE: Assuming the damage potential falls off as an inverse function of the distance cubed, then the damage potential at circle two would be one-eighth that at circle one, the damage potential at circle three would be one-twenty-seventh that at circle one, etc. - - Editor.


"For any odd-numbered column failure in row A, the adjacent even numbered columns would also necessarily fail. The still standing, extended, cantilevered header, from A11 to almost back where A8 was, is probably due to the seesaw effect, over A7 as an instant pivot point, as the A row collapsed sequentially to the right by either the truck bomb or supplemental demolition charges. If the header at column A8 had survived explosives, cascading floors could have caused it to fail. However, one would not expect such a long remaining cantilever."

Beyond Credulity

From what has been stated thus far, and considering only the potential damage from the truck bomb, Partin notes, there are a number of irreconcilable problems:

* If column A7 was brought down by the truck bomb, then most of the much smaller columns B1, B2, B4, B5, and B6 should not be standing, but they are.

* A truck bomb that could not bring down columns B1, B2, B4, and B5 could certainly not be expected to collapse the lower two floors of a much heavier column A7. Columns A7 and A8 should still be standing, but they are not.

* For a truck bomb of the size and composition reported, to be able to reach out on the order of 60 feet and collapse a reinforced column base the size of column A7 is beyond credulity. Even bringing down B3 at its range is highly suspect. Glass and plaster can be broken a long way off with explosives, but not heavy, reinforced, concrete columns.

However, he observes, if demolition charges were used to complement the truck bomb, the above problems disappear. But is such an explanation practicable? Yes, he answers, for the following reasons:

* Columns A3, A5, A7, and A9 were readily accessible from the sidewalk or the curb.

* Adequate demolition charges could easily and quickly have been put into position.

* A simple primacord interconnect (fuse) would not look too different from a piece of coaxial cord.

* If the bomb attack was intended to do more than deface the building, then inside help or loose security may have permitted placement of a charge at column B3.

Corroborating Opinions

Seven other explosives experts we interviewed endorsed General Partin's analysis as the most coherent and logical explanation of an otherwise unexplainable dilemma. These included professional civilian demolitionists, scientists, and bomb specialists who currently serve, or previously served, in military and police units.

Sam Gronning, a licensed, professional blaster in Casper, Wyoming with 30 years experience in explosives, told us the Partin letter "states in very precise technical terms what everyone in this business knows: No truck bomb of ANFO [ammonium nitrate fuel oil] out in the open is going to cause the kind of damage we had there" in Oklahoma City. "In 30 years of blasting, using everything from 100 percent nitrogel to ANFO, I've not seen anything to support that story."

Gronning notes that he recently detonated an ANFO charge more than three times the size of the one reportedly responsible for the Oklahoma destruction. "I set off 16,000 pounds of ANFO and was standing upright just 1,000 feet away from the blast," and even a bomb that size would not have caused the extent of, or pattern of, destruction experienced in the April 19th explosion, he said.

Dr. Rodger Raubach, who took his Ph.D. in physical chemistry and served on the research faculty at Stanford University, says, "General Partin's assessment is absolutely correct. I don't care if they pulled up a semi-trailer truck with 20 tons of ammonium nitrate; it wouldn't do the damage we saw there."

Raubach, who is the technical director of a chemical company, explained to The New American that "the detonation velocity of the shock wave from an ANFO explosion is on the order of 3,500 meters per second. In comparison, military explosives generally have detonation velocities that hit 7,000 to 8,000-plus meters per second. Things like TNT have a detonation velocity of about 7,100 meters per second. The most energetic single-component explosive of this type, C-4 -- which is also known as Cyclonite or RDX -- is about 8,000 meters per second and above. You don't start doing big-time damage to heavy structures until you get into those ranges, which is why the military uses those explosives."

Dramatic Drop-Off

Several very qualified experts we interviewed, however, took issue with the general's assessment. Jim Redyke of Dykon Inc., a demolition outfit in Tulsa, Oklahoma, has imploded hundreds of buildings and was a consultant at the Oklahoma City bomb site. Redyke told The New American that "this was consistent with the kind of damage (one would expect) from this size of bomb. This was a huge bomb!"

An Army Special Forces officer with explosives experience seconded this opinion, mentioning that nearly identical damage was done in the two 1983 Lebanon incidents, in which truck bombs were used to collapse the U.S. Marine barracks and the U.S. embassy.

Responding to these critiques, General Partin observed that it is not surprising that even many people with a professional knowledge of explosives might be unduly impressed with the size and explosive wallop of the bomb and fail to reckon with the fundamental laws of physics. "Yes, this was a big bomb with a big blast," agreed General Partin. "But most people fail to appreciate how inefficient a blast is in air and how dramatically its destructive potential drops off just a few feet from the explosion. In the Lebanon barracks bombing, the truck was driven directly under the building so that the explosion had maximum effectiveness against a much lower building with much smaller columns."

Demolitionists, Partin pointed out, rarely deal with the size of explosive charge used in the Oklahoma City truck bomb. "They use a couple hundred pounds of explosive that may be distributed among dozens -- or hundreds -- of small charges detonating microseconds or milliseconds apart." Those charges placed directly on, or in, a structure, "propagate a wave of deformation nearly a million pounds per square inch that pulverizes concrete, which has a yield strength of only about 50,000 pounds per square inch." But if you put just a few feet of air between the explosive and the target, the blast wave quickly drops from millions of pounds per square inch to thousands of pounds per square inch. It still makes an impressive boom, but has very little effect on heavy reinforced concrete.

It was this fact of physics which occupied much of Partin's attention in weapons development for the U.S. Armed Forces and made him an untiring crusader for the development and deployment of precision-guided munitions. General Partin cites accounts of the many laboratory and field tests he ran using large-yield bombs on numerous structures and targets. That experience, he says, together with all the known history of modern warfare shows that bombs can detonate close to a hard structure without causing severe destruction.

Advice to Congress

In his letter Partin strongly urged "that the U.S. Congress take steps to assure that evidence in Oklahoma City be independently evaluated by a collection of demolition experts from the private sector before the building is demolished. It is easy to determine whether a column was failed by contact demolition charges or by blast loading." The counsel for the defense did obtain a temporary delay of the demolition in order to have a team of experts examine the sight, but they have, as yet, revealed none of their findings. According to news coverage of the inspection by the defense team, it was a very brief examination and much of the most important evidence had already been removed or was still covered by rubble.

The most critical evidence that has to be assessed, said Partin, would be the collapsed column bases, especially those of columns A9 and B3. "If a satchel charge or linear cavity cutting charge or other explosive were used on the columns," he explained to The New American, "you would find a very distinctive signature." Is it likely that the defense team would have been able to make that kind of visual examination during its inspection? "Unfortunately, it doesn't look like the investigators had the time or opportunity. It is doubtful that they had access to the critical points."

Because of the care taken by the demolition team to cover the remaining debris, and the use of minimal demolition charges, verification of General Partin's analysis should still be possible -- if the evidence has not been deliberately destroyed. In addition, there are still many other related pieces of evidence to consider. As reported in the June 12th issue of The New American ("Were There Two Explosions"), the seismograms recorded independently by two seismometers in the Oklahoma City area on the morning of April 19th provide strong evidence of more than one blast.

There is also the matter of conflicting accounts concerning the discovery of other explosive devices at the Murrah building. Those who were present at the blast site during the early hours of the rescue, as well as the millions of viewers watching on television, remember the fear and horror they experienced when police and fire authorities announced that an additional bomb (or bombs) had been discovered in the still-smouldering building. Rescuers were forced to leave trapped victims and run for safety. Official accounts vary as to what object (or objects) actually were found to cause this alarm. Some say nothing was found. Others claim that it was a case of false alarm caused by a "dummy" bomb used as a teaching aid by the ATF. Still other reports assert that a military bomb squad removed an unexploded, but live, device (or devices). The New American is continuing to investigate these and many other still-unresolved and conflicting "facts" in this "worst terrorist attack on American soil."


Read More: http://www.apfn.org/apfn/okc_coverup.htm

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  • Beccy 2011/04/20 00:57:36
    I still don't buy the story that McVeigh and Nichels did this alone.
  • Autarchic Beccy 2011/04/20 11:05:12
    No reason to believe that, it was another inside job. All of the records from Waco were stored in that building.
  • Beccy Autarchic 2011/05/28 18:51:26
    I heard it stored whitewater records also
  • Autarchic Beccy 2011/05/28 19:39:21
    That could very well be too.
  • Manuel 2011/04/19 21:33:43
    It could add up to McVeigh had others working all this with him. Who knows for sure? - Others can still be out there waiting to commit there next blast.

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