Henry Petroski

Henry Petroski
Henry Petroskiis an American engineer specializing in failure analysis. A professor both of civil engineering and history at Duke University, he is also a prolific author. Petroski has written over a dozen books – beginning with To Engineer is Human: The Role of Failure in Successful Designand including a number of titles detailing the industrial design history of common, everyday objects, such as pencils, paper clips, and silverware. He is a frequent lecturer and a columnist for the magazines American...
NationalityAmerican
ProfessionAuthor
Date of Birth6 February 1942
CountryUnited States of America
My first book, 'To Engineer Is Human,' was prompted by nonengineer friends asking me why so many technological accidents and failures were occurring. If engineers knew what they were doing, why did bridges and buildings fall down? It was a question that I had often asked myself, and I had no easy answer.
Indeed, an engineer designing a structure is not unlike an artist painting one. Both start with nothing but talent, experience, and inspiration. The fresh piece of paper on the drawing board is as blank as the newly stretched piece of canvas.
Because they are so humbled by their creations, engineers are naturally conservative in their expectations of technology. They know that the perfect system is the stuff of science fiction, not of engineering fact, and so everything must be treated with respect.
It has been said, by engineers themselves, that given enough money, they can accomplish virtually anything: send men to the moon, dig a tunnel under the English Channel. There's no reason they couldn't likewise devise ways to protect infrastructure from the worst hurricanes, earthquakes and other calamities, natural and manmade.
Although engineers want always to make everything better, they cannot make anything perfect. This basic characteristic flaw of the products of the profession's practitioners is what drives change and makes achievement a process rather than simply a goal.
A common misconception about how things such as space shuttles come to be is that engineers simply apply the theories and equations of science. But this cannot be done until the new thing-to-be is conceived in the engineer's mind's eye. Rather than following from science, engineered things lead it.
What is commonly overlooked in using the computer is the fact that the central goal of design is still to obviate failure, and thus it is critical to identify exactly how a structure may fail. The computer cannot do this by itself . . .
I emphasize that virtually every engineering calculation is ultimately a failure calculation, because without a failure criterion against which to measure the calculated result, it is a meaningless number.
Failure is Central to engineering. Every single calculation that an engineer makes is a failure calculation.
A failed structure provides a counterexample to a hypothesis and shows us incontrovertibly what cannot be done, while a structure that stands without incident often conceals whatever lessons or caveats it might hold for the next generation of engineers.
Engineering is achieving function while avoiding failure.
Engineering, like poetry, is an attempt to approach perfection. And engineers, like poets, are seldom completely satisfied with their creations. They notice, even if no one else does, the world that is not quite le mot juste, or the hairline crack that blemishes the structure.
Engineers are not superhuman. They make mistakes in their assumptions, in their calculations, in their conclusions. That they make mistakes is forgivable; that they catch them is imperative. Thus it is the essence of modern engineering not only to be able to check one's own work but also to have one's work checked and to be able to check the work of others.
Relying on nothing but scientific knowledge to produce an engineering solution is to invite frustration at best and failure at worst.