Golden Gate Bridge

San Francisco, California

The Golden Gate Bridge is the iconic image of San Francisco in California and is probably the most photographed bridge in the world. The suspension bridge spans the Golden Gate strait, the one-mile-wide (1.6 km), three-mile-long (4.8 km) channel between San Francisco Bay and the Pacific Ocean. The structure links the American city of San Francisco, California – the northern tip of the San Francisco Peninsula – to Marin County, carrying both U.S. Route 101 and California State Route 1 across the strait. It has been declared one of the Wonders of the Modern Worldby the American Society of Civil Engineers. The bridge opened in 1937 and was, until 1964, the longest suspension bridge main span in the world, at 4,200 feet (1,300 m). Since 1964 its main span length has been surpassed by ten bridges; it now has the second-longest main span in the United States, after the Verrazano-Narrows Bridge in New York City. The total length of the Golden Gate Bridge from abutment to abutment is 8,981 feet (2,737 m). The color of the bridge is officially an orange vermilion called international orange. The color was selected by consulting architect Irving Morrow because it complements the natural surroundings and enhances the bridge’s visibility in fog. Aesthetics was the foremost reason why the first design of Joseph Strauss was rejected. Upon re-submission of his bridge construction plan, he added details, such as lighting, to outline the bridge’s cables and towers. In 1999, it was ranked fifth on the List of America’s Favorite Architecture by the American Institute of Architects. The bridge was originally painted with red lead primer and a lead-based topcoat, which was touched up as required. In the mid-1960s, a program was started to improve corrosion protection by stripping the original paint and repainting the bridge with zinc silicate primer and vinyl topcoats. Since 1990 acrylic topcoats have been used instead for air-quality reasons. The program was completed in 1995 and it is now maintained by 38 painters who touch up the paintwork where it becomes seriously corroded.