WTC Terrorist Training

22 September 2001

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To: <intelforum@his.com>
From: John Young <jya@pipeline.com>
Date: 16 Sept 2001
Subject: Terrorist Training

>This is a point I also wonder about. Did the attackers understand the
>the WTC structure well enough that they knew a major fire in the upper
>stories would lead to the sort of chain-reaction collapse that in fact
>happened? Or was that a horrible bonus effect that even the terrorists
>hadn't anticipated?
>
>If they knew and planned accordingly, their capabilities are truly
>frightening.

At least one of the attackers, Atta I believe, is reported to have studied urban development and architecture. Others studied electrical engineering. The attack does show an ability to plan regionally rather than merely tactically.

Each of the aircraft travelled a good distance from takeoff points rather than, say, flying from an airport near the target and going directly to a target.

There may be confidential procedures, technical or operational, which sounds an alarm if an aircraft deviates from a flight pattern immediately after takeoff or shortly thereafter. If so, then the trained pilots among the attackers could have known about those.

In any case, a multiple target attack, from relatively distant points of embarkation, involving 18 or so personnel, indicates skills among some of the attackers that are not altogether common outside corporate and military circles. Urban development is one of those but there are others, and relatively complex multiple flight planning is another.

It may seem only a matter of knives, box cutters, airline schedules, and pilot training, but to a regional planner there is more skill required than might first appear.

Secondly, architectural and engineering information about WTC was widely published during their construction and is readily available in public technical libraries. The same is true but somewhat less so about remedial measures implemented after the 1993 WTC bombing.

The towers have quite distinctive structural systems which were heavily discussed at the time they were built. There was considerable discussion then about the towers' capability of resisting a hit by a Boeing 707. Some of that was repeated in 1993.

Whether the studies underlying the 707 claims were ever published I do not know, but may well have been for their was intense debate about the safety of the buildings at the time of building them. I was a young architect just arriving in New York then and recall the fierce resistance put by city agencies, especially the fire department, to constructing the towers. Quite a few design professionals also criticized the towers' safety.

The Port Authority, its architects and engineers, and other backers, answered these challenges at length and in public. So there is much public material on the towers characteristics well beyond their totemic notoriety.

I was amazed at the towers collapse and did not expect it to happen. Terrible fires and localized damage but not total collapse. These are massive buildings and a plane, even travelling at high speed, should not have caused a total collapse. But the causes of collapse could be seen almost immediately by studying the imploding pattern.

The flexibility of the towers, designed to withstand high winds and earthquake, helped to absorb the impact. A more rigid structure might have sheared near the impact point or fractured at the base from taking a high hit, as happens in earthquakes to rigid buildings.

The towers distinctive lattice exterior structure also took the hit very well, redistributing the load once carried by the shattered parts over the remaining web. The lattice also contained the imploding floors quite effectively so that the debris hardly fell to the side.

I do not know if the imploding effect was designed to happen in the case of disaster, so tha the buildings would not tip to the side onto several blocks of other buildings.

If the imploding was designed to happen and that information was published the attackers could have known it.

At the moment I don't know that any of this has been made public and certainly those who would know it are not talking beyond providing information to the law enforcement investigators.

What can be done, though, is search technical libraries to see what was made public about attackable features of the towers, as well as whether any of this information was withdrawn after the 1993 attack. Not long ago plans of the NYC mayor's residence was withdrawn from the Department of Buildings for security reasons.

Plans of the WTC I believe were in hands of the Port Authority and were not at the NYC Department of Buildings because the PA is exempt from municipal code compliance, and did not have get municipal approvals for construction, the main reason the agency did not have to abide municipal objections to its construction.

The Port Authority is not a secretive agency, and its customarily makes its facilities information readily available. That was true at least before the first bombing. By then, I would assume that pretty thorough research had been done by attackers. The 1993 bombing could well have been a test run, even a ploy to mislead how much was known. Recall comments about how dumb the attackers were to attack at the strongest part of the buildings.

In sum, terrorist training is now likely to be as good as it can get, as good as the competition. It may know the competition better than the competition knows it.

I regret to say that the attack was brilliantly planned and executed. A classic for a variety of national security training schools to study, especially the engineers and urban warfare planners at West Point and Annapolis, even Colorado Springs and Langley. Its multi-dimensionality was professional.