Golden Gate Bridge - One of the World’s Most Beautiful Bridges
Three miles long and one mile wide, the Golden Gate Strait is the entrance to the San Francisco Bay from the Pacific Ocean with currents ranging from 4.5 knots to 7.5 knots. The strait was named in 1846 by John C. Fremont, a Captain in the US Army’s Topographical Engineers; it reminded him of a harbor in Istanbul named Chrysoceras meaning Golden Horn.
Before the Golden Gate Bridge was built, ferry boats taxied people across the bay. Many times the bay was dangerous to cross due to rough waters, wind and/or fog. People started dreaming of building a bridge to avoid the costs of ferrying and the dangerous weather conditions. More than a half-century before people began to seriously consider the feat, a railroad entrepreneur first promoted the idea for a bridge that would span the Golden Gate (US Postal Service). Then in 1916, a news article was written by a man, named James Wilkins from the San Francisco Call, suggesting the idea of building a suspension bridge and the idea began to gain more momentum.
Michael M. O’Shaughnessy, San Francisco’s city engineer, pursued the idea of building a suspension bridge to span the Golden Gate and asked Joseph B. Strauss to take on the project. Joseph Strauss, five feet tall and the biggest bridge builder of his time, had built more than 400 bridges in countries all over the world. The City and County of San Francisco undertook surveys to help Strauss obtain necessary information before he designed the bridge (Thoma). O’Shaughnessy launched a feasibility study to prove that it was possible to build a bridge across the Golden Gate and consulting engineer Leon S. Moisseiff, theorized that the feat of spanning the Golden Gate was feasible (Thoma). Before this time it was uncertain if such a structure could possibly be built because this length of bridge had never been built before. Strauss also undertook studies himself and, when all was finished, he included all the findings in a booklet signed by O’Shaughnessy and himself.
In June of 1921, Joseph Strauss submitted a preliminary sketch and estimates to the Mayor. Strauss’s plans confirmed that the project would cost between $25 million and $30 million. In the end the 1.2 mile long bridge cost $35 million. That same year a bill was introduced into the California Legislature creating "an incorporated bridge district to finance, construct and operate the project as a public toll bridge" (Museum of the City of S.F., b). The bill was passed and became law; it was amended in 1925 and 1931. Two years later the Mayor called a meeting to see what could be done to get the project underway; Representatives of 21 counties attended the first meeting. At this meeting the Bridging-the-Golden-Gate Association was formed to raise support from both sides of the Bay (Thoma). Strauss organized the political and financial efforts to raise the funds needed for the construction of the bridge. Before then there were not any funds and what money there was was going to the construction of the Bay Bridge between San Francisco and Oakland. "But it still took another seven years to secure the required approvals and funding before construction could begin" (US Postal Service).
In 1924, San Francisco and Marin Counties submitted to the government a joint application for a permit to build the bridge. On December 20, 1924, the Bridging-the-Golden-Gate Association was notified by Secretary of War, John Weeks, of the War Department’s approval of the bridge being built. Diamond drill borings were made to make sure piers and anchorages would be safe. The borings passed inspection and, on Feb. 12, 1930, the engineering board presented the report to the board of directors. On April 15, 1930, an application was submitted requesting approval from the Secretary of War for the plan proposed for approaching roads. These roads would have to go through two military reservations. The plan was approved by the War Department.
The Association received proposals from eleven leading bridge engineering firms in the U.S.; Joseph Strauss was selected as chief engineer on August 15, 1929. Consulting engineers were Leon Moisseiff and O.H. Ammann of New York and Professor Charles Derleth, Jr. of the University of California. Together they determined the basic design. These engineers, along with legal work and such, were paid through a three cent tax levy.
Six California counties formed themselves into a Golden Gate Bridge District. This district was comprised of the counties of San Francisco, Marin, Sonoma, Del Norte and part of Napa and Mendocino counties. On November 4, 1930, these "counties passed a $35 million bond issue to finance the building of the bridge, while pledging the property of these counties as security for the payment of the bonds" (McGloin). 145,697 voted yes, 47,005 voted no.
Despite the great amount of time and effort it took to work through the preliminary stage, construction started on January 5, 1933, and building the bridge during the Depression created jobs for people in the San Francisco area. A ceremony celebrating the start of construction was held and 200,000 people attended. Construction lasted for four years.
Bridge workers wore hard hats and safety ropes around their waists to protect them from potential injury. A safety net was also set up below the bridge to catch any men who might slip off from above. Unfortunately, on February 17, 1937, some scaffolding holding workers fell and broke through the safety net killing ten men.
Strauss’ design was enhanced by consulting architects Irving and Gertrude Morrow, a husband and wife team, who gave the bridge a sleek art deco look. The Morrows designed the towers with wide, vertical ribbing to accent the sun’s light on the structure and to emphasize the towers’ height; the portals decreased in width as they ascended into the sky. The railings were thinned and simplified to prevent obstruction of the driver’s view of surrounding areas. The posts were modest and uniform and the light posts, built in the same style, were angled.
Irving Morrow undertook the great task of designing the lighting system that lighted the bridge. Two important factors came into play when considering the type and style of lighting desired for the bridge: the enormous size of the project and the tremendous scale and dignity of the project (Thoma). "Because of the Bridge’s great size, Morrow did not want the same intensity of light on all of its parts. The effect would seem too artificial. The towers, for example, were to have less light at the top so they would seem to soar beyond the range of illumination" (Thoma). He believed flashy lighting would distract from the structure’s magnificence so he selected low pressure sodium vapor lamps, that gave off a subtle amber glow, to line the roadway. These original low pressure sodium roadway lights were replaced with high-pressure sodium vapor lamps 45 years later. Plastic amber lens were added to preserve the original warm glow. Unfortunately, due to a lack of funds, the tower lighting was not installed during the building of the bridge. Not until the bridge’s 50th anniversary were lights installed, accenting the great height of the towers. Pacific Gas & Electric Company funded much of the money needed for the tower lighting, which cost $1.2 million.
Unlike the US Navy, who wanted to paint the bridge black and yellow stripes for visibility for ships, Irving Morrow decided on the shade of orange called vermilion, also known as International Orange, to blend in with the colors of the surrounding hills. "Painting the Bridge is an ongoing task and the primary maintenance job. The Bridge paint protects it from the high salt content in the air which rusts and corrodes the steel components….The Bridge was painted when it was originally built with a red lead primer and a lead-based top coat. For the next 27 years, only touch up was required. By 1965, advancing corrosion sparked a program to remove the original paint and replace it with an inorganic zinc silicate primer and acrylic emulsion topcoat" (Thoma).
The original bridge fog horns were used for almost 50 years before replacing them was required. One horn was located at mid-span, while the other one was mounted at the south pier. "Vessel operators head[ed] into the Bay steer[ed] left of the south pier horn and right of the mid-span horn. Outbound vessels stay[ed] to the right of the mid-span horn" (Thoma). The deep, baritone sound of the horns guided vessels safely through the Gate and forewarned of incoming fog. Unfortunately, the two-tone fog horn at mid-span partly quit working in the 1970’s, one air valve gave way and it became a one-tone fog horn. This horn continued in this state until 1985 due to replacement parts being obsolete. In 1985, the original two-tone fog horns were replaced with new single-toned horns that differed in frequency from each other. Most ships today use radar but smaller vessels without such instruments use the guidance of the fog horns when visibility is low.
"The Bridge is also equipped with navigational and warning lights for travelers by sea and by air. Originally, a red rotating aircraft beacon shown on the top of each tower. In 1980, they were replace(d) with 360 degree flashing red beacons. The Bridge main cables are also marked with red cable outline lights. In 1983, they were replaced with new and more efficient lights. For seafaring vessels, there are red navigation lights on the south pier fender and white and green lights below the deck at mid-span" (Thoma).
When the bridge was completed it was quite an awesome structure. The length of the suspension span, including the main span and the side spans, was 6450 feet. The width of the bridge was 90 feet. The total length of the bridge, including its approaches, was 8981 feet. It was the longest suspension bridge in the world until 1964 when New York City’s Verrazano Narrows Bridge was finished being built. The bridge’s two towers were the tallest in the world at 746 feet. The height of the towers above the roadway was 500 feet and had a combined weight of 44,400 tons. The towers supported the cables that held the center sections in place. The combined weigh of these cables was 61,500 tons. The cables were each 7659 feet long and 36 ½ inches in diameter. Each cable was composed of 61 strands or 27,572 wires twisted together. The amount of wires used could have been spread out 80,000 miles or encircle the equator three times. At mid-span, which was 220 feet above the water, the bridge was able to swing 27 feet if there was a broadside wind of 100 miles an hour.
Huge pockets were excavated in the solid rock, found on each side of the Gate, to form a setting for the concrete anchorage blocks. These blocks, poured for the piers and anchorages, contained 30,000 cubic yards of concrete and "would [have] pave a five-foot wide sidewalk from New York to San Francisco" (Guideyou.com). "Its foundations extend[ed] to the greatest depth below water of any bridge built by man; one pier was sunk at 242 feet below water, and another at 200 feet. The deeper pier [was] bigger than the largest of the Pyramids and required more concrete than the Empire State Building in New York" (McGloin). The total weight of the bridge, anchorages and north and south approaches was 887,000 tons. Today, these measurements are the same even though the bridge has had to have some repairs.
The Golden Gate Bridge was finished on May 26, 1937 and was open for pedestrian use the next day. 300,000 people paid five cents each to walk on it that day, and, on the 28th, the bridge was opened to motorized vehicles at "twelve o’clock noon when President Franklin D. Roosevelt pressed a telegraph key in the White House to announce the event to the world. The Bridge opened ahead of schedule and under budget" (Thoma). Some 32,300 cars crossed the bridge that day paying 50 cents per car for the driver and up to three passengers. Any extra persons, besides the driver and three passengers, cost 5 cents each. The money earned from tolls helped pay for improvements and repairs needed on the bridge. As of December 31, 1997, more than 1.5 billion vehicles had crossed the bridge.
Joseph Strauss’s peers saw the difficulties of building a bridge of this size and length as an insurmountable task, but Strauss held out and he lived to see his dream come true even though he only survived a year after the bridge’s opening. Once the bridge was completed, Strauss wrote this ode entitled "The Mighty Task Is Done":
At last the might task is done; Resplendent in the western sun; The Bridge looms mountain high
On its broad decks in rightful pride, The world in swift parade shall ride Throughout all time to be.
Launched midst a thousand hopes and fears, Damned by a thousand hostile sneers. Yet ne’er its course was stayed. But ask of those who met the foe, Who stood alone when faith was low, Ask them the price they paid. High overhead its lights shall gleam, Far, far below life’s restless stream, Unceasingly shall flow….(McGloin).
"A dramatic test, which the Golden Gate Bridge passed successfully, came on Saturday December 1, 1951. Between 5:55 P.M. and 8:45 P.M. the bridge was closed to traffic because of a violent storm which generated a gale with a velocity of seventy miles an hour. The deck of the bridge swayed twenty-four feet from side to side and five feet in the perpendicular dimension. Since the bridge was designed to sustain a twenty-seven-foot sway, no serious effects came from this dramatic moment. Close examination of the structure later indicted only minor damage" (McGloin).
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McGloin, John Bernard. [ curator@sfmuseum.org ]. "Symphonies in Steel: Bay Bridge and the Golden Gate." [ http://www.sfmuseum.org/hist9/mcgloin.html ]. 1978.
Museum of the City of San Francisco.
Owens, Thomas. (1997). The Golden Gate Bridge. New York, New York: The Rosen Publishing Group’s PowerKids Press.
Thoma, Michael Paul. [mike@thoma.com]. "Golden Gate Bridge Facts." [http://www.thoma.com/thorma/ggbfacts.html]. 1996.
United States Postal Service. [http://www.usps.gov/feedback/feedback.htm]. "Golden Gate Bridge." [http://www.usps.gov/kids/stompfeature77.html].
Fred J. Becker, Architect
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