Complete and reliable structural data for World Trade Center towers 1 and 2 is surprisingly difficult to obtain. Data must be gathered and cross-referenced among a variety of sources. Perhaps the greatest amount of data has been gathered by the National Institute of Standards and Technology as a result of its 3 year building and fire safety investigation. The final report of the NIST study details its findings and includes structural data for the towers that was used in the models it developed. Unfortunately, the NIST structural and architectural data is incomplete. For instance, column schedules are given only over a range of floors rather than the full building. Recently (after the previous was written), the NIST SAP2000 models became publicly available, which helps fill in the picture regarding NIST's data. It should be noted here that the NIST study did not include a full collapse analysis.
Another important resource is a set of architectural drawings that became publicly available in March of 2007. It is anticipated that the drawings will provide valuable information regarding the column schedules and, hence, help fill in the gaps in the NIST data. It is noted that the drawings are not the equivalent of the building blueprints which would be the most preferred source of data. To date, the blueprints remain unavailable publicly. In the absence of the blueprints, this project will regard the drawings as authoritative. When discrepancies are encountered between data given by the drawings and data obtained from other sources, the data from the drawings will be given precedence.
Occasionally, data from other sources such as papers (e.g. Astaneh-Asl, World Trade Center, Field Investigations and Analyses) and websites (e.g. http://911research.wtc7.net). No discrimination will be made on the basis of the "type" of the source, such as the 911research site. The sole interest of this project is the accuracy of the data.
