Design 
  Community 
  Architecture 
  Discussion 
 

Message - Re: WTC collapse: some facts

    Responses | Architecture Forum | Architecture Students | Architecture Scrapbook | ArchitectureWeek    
   

Posted by  lewis hill on March 12, 2003 at 19:36:39:

In Reply to:  WTC collapse: some facts posted by Richard Haut on September 29, 2001 at 02:00:22:

Actually it's not correct that the 707, whose impact the towers were
designed to survive, is "much lighter" than the 767.

The maximum takeoff weight for a Boeing 707-320B is 336,000 pounds.
The maximum takeoff weight for a Boeing 767-200ER is 395,000 pounds.

The wingspan of a Boeing 707 is 146 feet.
The wingspan of a Boeing 767 is 156 feet.

The length of a Boeing 707 is 153 feet.
The length of a Boeing 767 is 159 feet.

The Boeing 707 could carry 23,000 gallons of fuel.
The Boeing 767 could carry 23,980 gallons of fuel.

The cruise speed of a Boeing 707 is 607 mph = 890 ft/s,
The cruise speed of a Boeing 767 is 530 mph = 777 ft/s.

So, the Boeing 707 and 767 are very similar aircraft, with the main
differences being that the 767 is slightly heavier and the 707 is faster.

In designing the towers to withstand the impact of a Boeing 707, the designers would have assumed that the aircraft was operated normally. So they would have assumed that the aircraft was traveling at its cruise speed and not at the break neck speed of some kamikaze. With this in mind, we can calculate the energy that the plane would impart to the towers in any accidental collision.

The kinetic energy released by the impact of a Boeing 707 at cruise speed is
= 0.5 x 336,000 x (890)^2/32.174
= 4.136 billion ft lbs force (5,607,720 Kilojoules).

The kinetic energy released by the impact of a Boeing 767 at cruise speed is
= 0.5 x 395,000 x (777)^2/32.174
= 3.706 billion ft lbs force (5,024,650 Kilojoules).

From this, we see that under normal flying conditions, a Boeing 707 would smash into the WTC with about 10 percent more energy than would the slightly heavier Boeing 767. That is, under normal flying conditions, a Boeing 707 would do more damage than a Boeing 767.

Moreover, fully fueled, a 707 would have over twice the 10,000 gallons of fuel the 767s were carrying. Certainly the designers of the towers must have considered effects of the fuel load in such an event.

 
ArchitectureWeek     Buildings     Architects     Types & Styles     Search
Library     Places     Building Photos     Free 3D Models     Archiplanet

Architecture Search   by name of Building, Architect, or Place:
 
Examples:  "Fallingwater",  "Wright",  "Paris"
Advanced Search



Post a Response -

Subject:       


This is an archive page. Please post continuing discussion to the new Architecture Forums.

To post successfully to the new membership-based DesignCommunity Forums:

    1) Go to the new forums area.
    2) Register with a valid email address.
    3) Receive and respond to the confirmation email.
    4) Then login to the new forum system.


Architecture Forum | Students Forum | Scrapbook | Home Design | 3D Gallery | E-Design
 

Special thanks to our Sustaining Subscribers including BuilderSpace.com .

Home | Great Buildings | CAD Outpost | DesignWorkshop | Free 3D | Gallery | Search | ArchitectureWeek
This document is provided for on-line viewing only. http://www.DesignCommunity.com/discussion/26121.html