Beauty is the Rodney Dangerfield of public construction. It don’t get no respect. We may find a particular bridge or building beautiful – St. Paul’s High Bridge or Landmark Center, for example – but we seldom explicitly discuss how to consider beauty when spending tax dollars.
Economics assumes society always faces trade-offs. Is there a trade-off between cost and beauty in public structures? That is a relevant question as we prepare to replace the collapsed I-35W bridge in Minneapolis. Can we get a distinctive, beautiful structure without sacrificing scarce money or time?
In 1928, Maillart won the contract for his masterpiece not because of appearance but because his bid of $35,000 was the lowest of 19 submitted. A subcontractor got $8,500 for the temporary timber framework to build the bridge.
Maillart certainly did not discount aesthetics, but all of the graceful compound curves in his bridge derive from calculating the minimal amounts of concrete and reinforcing steel needed to safely balance the forces of tension and compression involved in bridging the 434-foot-wide Salgina ravine. Rather than imitating stone, steel, or timber bridges, Maillart mastered the engineering and art inherent in a new material, reinforced concrete. Gustav Eiffel had done the same with wrought iron 50 years earlier and similarly produced beautiful, economical bridges.
Maillart achieved a masterpiece, frequently described as “the most beautiful bridge of the 20th century.” It is hard to figure how it could have been built more cheaply.
Unfortunately, his feat could not easily be duplicated today. Maillart built his masterpiece in a time of economic hardship. Steel and cement were expensive, especially when hauled high into the Alps, far from any railroad. But skilled labor was cheap.
In 1930, having master carpenters spend hours building complex forms to save a few tons of steel and cubic meters of concrete paid off. Replicating the bridge today would cost much more than a simpler but uglier alternative.
Standardization can save time and money. In the heyday of railroad building 130 years ago, simple steel bridges that could quickly be erected by unskilled workers cost less than the masonry arches used in Europe and allowed new railroad lines to carry freight months sooner. Standardized designs similarly speeded interstate highway construction in the 1950s and 1960s.
Generally, as the size of a bridge or building grows, the relative cost of good design and aesthetic features drops as a proportion of the total. Having architects draw original bridge designs for every creek I-90 crosses in southern Minnesota would be costly. By contrast, giving architectural grace to the Golden Gate Bridge added little expense.
New technology can help. The cable-stayed bridges made famous by Swiss designer Christian Menn and Spanish architect Santiago Calatrava, among others, often are less expensive to erect than traditional suspension bridges of the same span because they require less labor and material. Cable-stayed bridges are more common in Europe, where they have often been used to replace bridges destroyed in World War II.
Designing any new bridge from scratch takes time, but doing without the I-35W bridge is costly to truckers and commuters, so speed of replacement is important.
One way to save time is to adapt a beautiful design already constructed elsewhere. Boston’s newest bridge across the Charles River, designed by Menn and built in 2002, quickly comes to mind. It has 10 lanes and is 60 percent wider than our collapsed bridge, and its overall length is about the same. It cost $115 million when opened to traffic in 2003. Unfortunately, federal inspectors found problems with a few cable termination plates in late August; the cause is unclear at this point. But there are many other beautiful cable-stayed bridges, including ones in Savannah, Ga., and Baytown, Texas.
Minnesotans might have to swallow their pride to copy an existing bridge, but a bold design and sweeping lines would enhance Minneapolis’ landscape. I’d pay something for that, but only the political process can determine the outcome, probably very imperfectly.
See other bridges by these designers.
© 2007 Edward Lotterman
Chanarambie Consulting, Inc.