a request for clarification
The events of September 11, 2001, marked a turning point in modern history. The collapse of the World Trade Center towers continues to generate discussions and debates, prompting a closer examination of the official explanations.
In this open letter, Anthony Szamboti addresses Professor Bazant, requesting a correction of four papers published in the Journal of Engineering Mechanics. Szamboti highlights several inconsistencies and inaccuracies in these papers’ analysis of the collapse of the North Tower (WTC 1).
Let us delve into the concerns raised by Szamboti and the implications they have for further investigation.
Reassessing Key Parameters
Szamboti raises concerns about the values used for the velocity, mass, and column strength of the descending upper section of the building in Bazant’s papers. By pointing out discrepancies in the measurements of velocity, Szamboti suggests that the free fall assumption made by Bazant is inconsistent with actual observations. The use of inaccurate values for velocity and mass leads to a significant overestimation of the kinetic energy of the upper section, potentially influencing the collapse progression.
Here’s a table illustrating the key point raised in the paper regarding the discrepancy in mass estimation for the descending upper section of the North Tower:
|Bazant’s Papers||NIST Report|
|Mass of Upper Section||58 x 10^6 kg||33 x 10^6 kg|
|(Descended Stories)||or 54.18 x 10^6 kg|
|Mass per Story||3.87 x 10^6 kg||2.75 x 10^6 kg|
Note: The values in the table are based on the information provided in the open letter and are for illustrative purposes only.
Additionally, the discrepancy in column cross-sectional areas and yield bending moments further adds to the inconsistency. Szamboti argues that the values presented by Bazant for the columns’ cross-sectional area do not align with the associated yield bending moments. These inconsistencies cast doubts on the accuracy and reliability of Bazant’s calculations.
Revisiting the Mass of the Descending Upper Section
One of the critical concerns raised by Szamboti is the use of a mass value of 58 x 10^6 kg or 54.18 x 10^6 kg for the descending upper section, which appears to correspond to 15 or 14 stories, respectively, according to Bazant’s papers.
However, Szamboti argues that the actual in-service load of the 12-story upper section can be calculated as 33 x 10^6 kg based on the National Institute of Standards and Technology (NIST) report. This disparity in mass estimation suggests that Bazant’s use of a higher mass value may not reflect the real conditions during the collapse.
Here’s a chart that further illustrates the difference in mass estimation for the descending upper section of the North Tower:
|Story Number||Mass per Story (Bazant’s Papers)||Mass per Story (NIST Report)|
|98||3.87 x 10^6 kg||2.75 x 10^6 kg|
|99||3.87 x 10^6 kg||2.75 x 10^6 kg|
|100||3.87 x 10^6 kg||2.75 x 10^6 kg|
|110||3.87 x 10^6 kg||2.75 x 10^6 kg|
|111||3.87 x 10^6 kg||2.75 x 10^6 kg|
|112||3.87 x 10^6 kg||2.75 x 10^6 kg|
This chart highlights the discrepancy in mass estimation between the two sources and emphasizes the difference in assumptions made regarding the actual mass of the descending upper section of the North Tower during its collapse.
Note: The values in the chart are based on the information provided in the open letter and are for illustrative purposes only.
Furthermore, Szamboti points out that Bazant’s earlier calculations using the vibrational period of the tower align closely with the values discerned from the NIST report. This raises questions about why Bazant did not use these values in his subsequent papers, as it would have provided a more accurate representation of the collapse dynamics.
Implications for the Investigation
The inaccuracies highlighted by Szamboti have significant implications for the forensic analysis of the World Trade Center tower collapses.
The overestimation of velocity, mass, and kinetic energy of the upper section could potentially influence the likelihood and progression of collapse. By using maximum design loads instead of actual in-service loads, the analysis becomes less accurate and impedes a comprehensive investigation into the collapse mechanisms.
Here’s a chart that illustrates the implications of the errors in Bazant’s papers on the collapse of the WTC Towers:
|Inaccurate Velocity Calculation||Bazant’s papers used an incorrect velocity of the descending upper section, leading to an overestimated energy.|
|Overestimated Mass||The papers overestimated the mass of the descending upper section, affecting the overall kinetic energy.|
|Inconsistent Column Strength||The papers provided inconsistent column strength values, potentially leading to inaccurate collapse analysis.|
|Flawed Conservation of Momentum||Use of incorrect mass values in momentum loss calculations resulted in underestimating the velocity loss.|
|Limited Video Resolution||The claim of insignificant velocity loss was based on incorrect values, disregarding observable video evidence.|
|Lack of Investigation||The presence of potential charges in the buildings was not investigated, hindering a comprehensive analysis.|
|Questionable Collapse Propagation||The papers did not explain the horizontal propagation across the building, leaving gaps in the collapse analysis.|
|Misinterpretation of Observations||Focused ejections and rapid descent without deceleration were not adequately explained, raising doubts.|
Please note: that the information in the chart is based on the content provided in the open letter and is for illustrative purposes only.
Moreover, Szamboti points out the lack of analysis and explanation in the NIST report for the horizontal propagation of the collapse across the building. He highlights the rapid horizontal progression observed across the 98th floor, which cannot be easily explained by natural causes.
These observations, coupled with focused ejections during the collapse, suggest the need for a thorough investigation into the possibility of controlled demolition.
Anthony Szamboti’s open letter to Professor Bazant highlights crucial inconsistencies and inaccuracies in the analysis of the collapse of the North Tower.
By bringing attention to the discrepancies in velocity, mass, and column strength, Szamboti raises concerns about the accuracy and reliability of the conclusions drawn in Bazant’s papers.
These inaccuracies hinder a comprehensive forensic analysis and underscore the importance of revisiting the collapse of the World Trade Center towers.
A meticulous investigation is necessary to address the unanswered questions and ensure an accurate understanding of the events of September 11, 2001.