In response to an editorial I wrote recently about declining enrollment in engineering, I received dozens of letters from design engineers who are discouraged and disillusioned by their career choice. Many of you say you feel unappreciated and undervalued, noting that your technical achievements frequently go unrecognized by senior management at your companies and are ignored by the general public.
Sadly, the horrific events of September 11th were a reminder of the way in which engineers do make a difference.
Considered an engineering marvel in their day, the twin towers of the World Trade Center were known as tube buildings. Instead of heavy exterior masonry and internal bracing, their outer walls consisted of a series of steel columns with skins of glass and steel. This innovative and efficient design gave the towers extremely high lateral stiffness and strength-sufficient enough to withstand winds up to 200 miles per hour and, unimaginably, the impact force of a Boeing 767.
The building design ultimately proved vulnerable to 5,000 gallons of ignited jet fuel. But the fact that the towers withstood forces that likely exceeded design specifications bought precious minutes of time. In the 100 minutes that the South Tower and 56 minutes the North Tower remained standing after the hijacked airplanes slammed into them, countless numbers of people were able to flee the burning buildings.
I'm sure many of you never expect that your creations will be exposed to anything close to worst-case conditions. I'm sure you hope and pray that it never happens. But the fact that you routinely design your products to meet stringent safety specs means that the rest of us do not have to worry. We simply take our safety for granted.
Until terrorists rocked our world, most of us had taken elevators up to the top floors of a tall building without a second thought. We've routinely traveled on airplanes, and trust they won't fall out of the sky. We've driven to work in our cars, expecting to arrive safely. The list goes on and on.
For this sense of security, I am grateful to design engineers everywhere. Because, in a very real way, you help to make us free.