What is your reaction when you hear about recalls due to product defects? How about your reaction to more serious failures, like a collapsed building or bridge? I have encountered some people who are quick to conclude that a failure is the result of poor design. Do you think this is a fair conclusion? Engineers are trained professionals who do their best to provide economical designs while holding "paramount the health, safety, and welfare of the public" (EGGP Act). Sometimes designs are flawed, but often there are other factors. I'd like to hear your opinions on failures (either in general or with respect to specific cases). There are many to choose from, but here is a short list of suggestions:
- Dell laptop battery recall
- the Ford Pinto
- the space shuttle explosions (Challenger and Columbia)
- the McDonnell Douglas DC-10
- collapse of the Tacoma Narrows bridge
- collapse to the World Trade Center buildings
- collapse of the I-35W Mississippi River Bridge
- collapse of the De la Concorde overpass near Laval, Quebec

I think there is a reasonable amount of leeway for designers. Of course nobody wanted or intended the Columbia rocket to explode, it was just a truly unfortunate event. Similarly I don't think you could possibly blame the World Trade Center collapse on poor design; no designer could anticipate a plane flying into their building, and even then the fact the building stayed standing momentarily was a testament to their design.

I think what often bothers people more than a design failure is any attempt to cover it up to avoid bad publicity. I still don`t understand how a company thinks hiding a mistake or problem rather than admitting and fixing it is going to win them any points with the buying public.

Well, I think someone is obviously being irresponsible. How could those companies ignore their guilty conscience, taking money but not properly completing the product? Sooner or later, their mistakes will be found out and it will only cost them not only damage to reputation, but along with other greater financial lost.

Eric: I agree that designers were not at fault for the space shuttle disasters or the World Trade Center collapse. The World Trade Center probably was designed to sustain accidental collision of a smaller aircraft, but designing for an intentional collision with a large, fully-fueled aircraft would have been thought to be beyond all reason and would have increased construction costs dramatically. As for the space shuttle disasters, I think these accidents were not really design faults (though in both cases, improved design could have prevented the disasters), but were definitely preventable. NASA actually has a rather poor safety record, and it is not simply because their engineers are venturing into unknown territory. Safety has historically not been part the company culture at NASA, so many warnings and near-misses were not properly addressed.

I completely agree that the public reacts more strongly when they find out a company has been covering up mistakes.

Elaine: Is there any particular instance you are referring to? If this is a general statement, I disagree. Some problems are simply unknown and not discovered until they are reported by the public. Certainly the recent recall on some baby toys for the presence of lead paint was inexcusable, as it is common knowledge that lead is poisonous and babies like to put stuff in their mouths. But I don't think it is fair to say that de Havilland was irresponsible because the Comet (the world's first commercial jetliner) was discovered a few years after production to be susceptible to catastrophic failure, as their design exceeded all requirements for the design of aircraft at that time.

I have to disagree with Eric and Adam on this. The designers of the world trade center were at fault. To have such tall buildings and not prepare the design for the worst is a flaw, which explains why the september 11 is listed among engineering disasters. And root cause of the problem was poor design

I don't know Frank. I would consider something like the John Hancock Tower or the Citigroup Center to be real engineering disasters. Poor design is having your building be threatened by a threat you can reasonably anticipate; in both the cases I cited, high winds common to the area could essentially destroy or ruin the buildings.

Perhaps the World Trade Center could have been better designed, but I feel like blaming the engineers for the failure is like blaming the engineers of the Frauenkirche for the bombing of Dresden.

It is very easy to blame designers after the fact. The events of September 11, 2001 would not have been a reasonable design scenario at the time the towers were built. The hijacking of an aircraft is a rare event, and as far as I know, hijackers had never used the plane itself as a weapon before. The first case that I know of was an attempt to hit the Eiffel Tower in 1994. The towers were built in the early 1970's, while the Boeing 767s used to destroy the towers didn't come into production until 1982. Eric is right, designers can only be expected to consider reasonable scenarios. It'd be impossible to design for the absolute worst case, as a barrage of nuclear warheads would then have to be considered. Engineers always design for the improbable in order to maintain a high level of safety, but they also have to use some judgment in deciding what is a reasonable worst design case.

I know where you guys are coming from,I had the same view until I did a research on this issue in my first year design class. I am not saying that the design was totally bad- it was a flaw that they didn't prepare the building for a rare event( that had occurred twice before the building was built), even after the structural engineers considered it. The Federal Emergency Management Agency (FEMA) only declared the design sound after investigations because the design met its standards. Engineering ethics teaches we go beyond the standards when we sense danger in mere conformity. Here is an excerpt from Wikkipedia:

"The structural engineers working on the World Trade Center considered the possibility that an aircraft could crash into the building. In July 1945, a B-25 bomber that was lost in the fog had crashed into the 79th floor of the Empire State Building. A year later, another airplane nearly crashed into the 40 Wall Street building, and there was another near-miss at the Empire State Building.[8] Leslie Robertson, one of the chief engineers working on the design of the World Trade Center, has since claimed to have personally considered the scenario of the impact of a jet airliner—a Boeing 707—which might be lost in the fog and flying at relatively low speeds, seeking to land at JFK Airport or Newark Airport. However, Robertson has provided no documentation for this assertion"

I can give you links to Journal articles on this if you want.

"In 2003 Asif Usmani, Professor of Structural Engineering at University of Edinburgh, published a paper with two colleagues. They provisionally concluded the fires alone, without any damage from the airplanes, could have been enough to bring down the buildings. In their view, the towers were uniquely vulnerable to the effects of large fires on several floors at the same time"

Sorry I am posting so much. I m just sharing what I found

Like I said, the design likely would have considered an accidental collision, but not an intentional one. An accidental collision is more likely to be at lower velocity, and the fuel tanks are more likely to be nearly empty. As for the vulnerability to fire, the same could be said for many buildings. WTC 7, which collapsed despite minimal damage, was similarly vulnerable to uncontrolled fire. Any steel-framed building is vulnerable to a large fire if fire fighters cannot get to it. We deal with this by taking measures to reduce the probability of large fires. These include fire suppression systems to prevent a small fire from becoming a large fire (sprinklers, wall-mounted extinguishers, etc.), and the use of materials that are either non-combustible or difficult to ignite (gypsum wallboard, ceiling tiles, spray-applied fireproofing of the structural elements). This approach is intended to control small fires, based on the assumption that most fires will start small (and usually by accident).

Using reinforced concrete for all structural elements would be the only practical way to design tall buildings to endure large fires.