THINKING BIG : It Looked Good on Paper

Along with humankind’s many successes in engineering and design, there have been some notable flops. A short list:

Leaning Tower of Pisa: The landmark campanile, 184.5 feet tall, is about 17 feet out of perpendicular, a tilt increasing by about 1/20th of an inch a year. Built of white marble with eight tiers of arched arcades, the campanile began to lean during construction in the 12th Century. Although the foundation was dug down to 10 feet, the builders did not reach bedrock for a firm footing. In the 1960s, cement was added to the foundation to strengthen the tower, but it is still threatened with collapse.

The Dingo Fence: Beginning in the 1880s, Australians erected the world’s longest structure, a six-foot-high fence stretching 3,700 miles across three southeastern states to protect sheep herds from the dingoes--wild dogs. But the fence has proved less impressive than long. The dingoes crawl through holes torn in it by larger animals and dug underneath it by burrowing rabbits and wombats. Authorities and private ranchers have largely abandoned trying to maintain it.

San Francisco’s “Eyesore” Freeways: Products of California’s freeway-happy 1960s, sections of the Bay City’s Embarcadero freeway and Interstate 280 blocked waterfront views and were halted by public protest. They became the infamous “freeways to nowhere,” a network of double-decked, half-finished stubs. The 1989 Loma Prieta earthquake damaged the structures and led to orders for demolition.