Pushing the Limits, New Adventures in Engineering
by Ed Buch, CSI, CCS, AIA

In Henry Petroski’s twelfth, and latest book, Pushing the Limits, New Adventures in Engineering, (2004, Alfred A. Knopf , New York, 288 pages), structural and civil engineering innovations in the design of bridges, dams, and buildings, are used to describe the signal role engineers have played in the evolution of technology over the past 150 years. Unlike some of Petroski’s other books, this one uses examples of things we can relate to as he describes the wonders of engineering. It will appeal to anyone with an interest in the evolution of engineering design.

Big structures aren’t always better ones, or more interesting ones for that matter. Nevertheless, in the history of construction, spanning greater distances and building taller buildings, or higher dams, has been a key factor behind the development of new technologies. The book offers numerous examples and explains the ingenious solutions created by engineers to build bigger.

The chapters describing the progression of bridge design include stories of the earliest American suspension bridges by John Roebling, the bridges designed by Modjeski, Gustav Lindenthal, Othman H. Ammann, and others. The Brooklyn Bridge, the Ben Franklin Bridge in Philadelphia, and the historic, reinforced concrete arch bridges along US Highway 101 in California and Oregon are among those presented. Each bridge was daring in its own way and many of them are still landmarks today.
There are several examples of bridges that failed. The Tacoma Narrows Bridge is probably the most famous. The recent problem with the Millennium Bridge across the River Thames in London is another case. This extremely graceful pedestrian footbridge is a beautiful integration of art and engineering. When it was completed in 1999, it suffered excessive side sway resulting from the sympathetic footfall of walkers on the bridge. To solve the problem, a unique combination of dampers and stiffeners was installed under the bridge deck. Since these were largely out of view to people on the bridge, its beauty was preserved.

The chapters on structural engineering innovation in buildings will be of particular interest to architects. The story of SOM structural engineer, Fazlur Kahn, and his concept of the bundled tube structural system in the Sears Tower is presented. Santiago Calatrava’s unique blend of structure and architecture is another illustration of contemporary genius.

The collapse of the St. Francis dam is a story close to home. It describes William Mulholland’s rise to become the chief engineer of the Los Angeles Water Co. and how hubris, coupled with poor design, lead to the collapse of the dam in 1928. Half a world away the ecological and social considerations associated with the construction of the Three Gorges dam, on the Yangtze River in China, are described. Here, the world’s largest hydroelectric dam is being constructed, a truly gargantuan project on any scale.

Ed Buch is an architect in the Los Angeles office of Leo A Daly. A Nebraska native, he has worked in Los Angeles since 1988. Prior to that, he worked in Omaha and Lincoln, Nebraska, and 5 years in Riyadh, Saudi Arabia. He has been member since 1981, and is currently an Institute director from the West Region, CSI.