Engineering Disasters and Learning from Failure

The role of the engineer is to respond to a need by building or creating something along a certain set of guidelines (or specifications) which performs a given function. Just as importantly, that device, plan or creation should perform its function without fail. Everything, however, must eventually fail (in some way) to perform its given function with a sought after level of performance. Hence, the engineer must struggle to design in such a way as to avoid failure, and, more importantly, catastrophic failure which could result in loss of property, damage to the environment of the user of that technology, and possibly injury or loss of life. Through analysis and study of engineering disasters, modern engineering designers can learn what not to do and how to create designs with less of a chance of failure.

What Makes a Failure Into an "Engineering Disaster"?Much of the reason why we consider an engineering failure to be an engineering "disaster" has to do with public perception of risk. For example, in 1992 roughly the same number of fatalities occurred (in the United States) in transportation accidents involving airplanes (775), trains (755), and bicycles (722). Yet the public perception of the risk associated with air travel is often much higher than that for trains and certainly for bicycles. This stems from two reasons: (1) the large loss of life (and associated wide spread news reporting) resulting from a single air crash, and (2) the air passenger's lack of control over their environment in the case of air or, to a lesser degree, rail accidents. Both of these reasons results in increased fear, and hence a higher degree of perceived risk. Primary Causes of Engineering Disasters The primary causes of engineering disasters are usually considered to be human factors (including both 'ethical' failure and accidents) design flaws (many of which are also the result of unethical practices) materials failures extreme conditions or environments, and, most commonly and importantly combinations of these reasons A recent study conducted at the Swiss federal Institute of technology in Zurich analyzed 800 cases of structural failure in which 504 people were killed, 592 people injured, and millions of dollars of damage incurred. When engineers were at fault, the researchers classified the causes of failure as follows:

Insufficient knowledge ............................... 36% Underestimation of influence ......................... 16% Ignorence, carelessness, negligence .................. 14% Forgetfulness, error ................................. 13% Relying upon others without sufficient control ....... 9% Objectively unknown situation ........................ 7% Unprecise definition of responsibilities ............. 1% Choice of bad quality ................................ 1% Other ................................................ 3% M. Matousek and Schneider, J., (1976) Untersuchungen Zur Struktur des Zicherheitproblems bei Bauwerken, Institut für Baustatik und Konstruktion der ETH Zürich, Bericht No. 59, ETH.