Typically, highway bridges have about 50 years. But over in England, they have iron bridges approaching 250 years. In France, there are Roman aqueducts that are approaching 2,000 years old. So a bridge can last a very long time if it's built properly in the first place and then maintained properly.
Because every design must satisfy competing objectives, there necessarily has to be compromise among, if not the complete exclusion of, some of those objectives, in order to meet what are considered the more important of them.
Companies selling a product play down its vulnerability and emphasize its robustness. But only after technology leaves the dock is it really tested. For human operators in control of a supposedly infallible system, complacency and overconfidence can take over, and caution may be thrown to the wind.
Failures are much more dramatic than successes, and people like drama. I think this is why automobile races draw such crowds. People expect spectacular crashes, which we tend to find more interesting than cars just racing around the track. The same is true of bridges, buildings, or any structure or machine.
For as long as I can remember, I have been fascinated by things large and small. I wanted to know what made my watch tick, my radio play, and my house stand. I wanted to know who invented the bottle cap and who designed the bridge. I guess from early on I wanted to be an engineer.
I have always been fascinated by the way things work and how they came to take the form that they did. Writing about these things satisfies my curiosity about the made world while at the same time giving me an opportunity to design a new explanation for the processes that shape it.
As long as there are things to wonder about, there are stories to be written about them. That makes me happy, because writing about things seems to be my thing.
We call the fates of the Titanic and the Concordia - as well as those of the space shuttles Challenger and Columbia - 'accidents.' Foreseeing such undesirable events is what engineers are expected to do. However, design trade-offs leave technological systems open to failings once predicted, but later forgotten.
There's so much written about the Titanic, and it's hard to separate what's fact and what's fiction. My understanding is that the way the Titanic was designed, the emphasis was placed on surviving a head-on collision.
The space shuttle was designed, at least in part, to broaden our knowledge of the universe. To scientists, the vehicle was a tool; to engineers, it was their creation.
I relax by looking at things and reading about things. Even the simplest thing can reveal a great deal about the world around us. It relaxes me greatly to sit back with my feet up and look around my study at the everyday things that surround me.
Case studies of failure should be made a part of the vocabulary of every engineer so that he or she can recall or recite them when something in a new design or design process is suggestive of what went wrong in the case study.
The definition of 'safe' is not strictly an engineering term; it's a societal term. Does it mean absolutely no loss of life? Does it mean absolutely no contamination with radiation? What exactly does 'safe' mean?
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.
