The Golden Gate Bridge is one of the most recognizable and photographed landmarks in the world, the main transport artery between the city of San Francisco and Marin County.It is a symbol of American ingenuity and courage in the field of bridge building. For 27 years after its construction, it held the status of the largest suspension bridge in the world. At present, its capacity is 40 million vehicles per year.
Construction of the Golden Gate Bridge
For many years San Francisco and Marin County connected only by ferry services. Each car crossing took 17-20 minutes and cost $ 1. Over the years, the demand for them increased, and the ferry company’s capacity was not enough. The question of building a road bridge across the bay arose sharply. However, this idea seemed to many just crazy because of the powerful winds and currents in the bay, frequent fogs, active navigation and deep bedding of solid rocks.
Facility design and financing
Despite the difficult conditions for potential construction, one daredevil and enthusiastic architect found.
Joseph Strauss is called the “father” of the Golden Gate of San Francisco . He developed the cantilever design and did a tremendous job of promoting it among the population, in administrative circles, as well as in the military department. It was only thanks to the efforts of Strauss, who was simultaneously an architect, promoter and manager, that the bridge project became a reality.
D. Strauss received a building permit on August 11, 1930 on the terms of cooperation with engineers and designers who had more experience in bridge construction. They were Lev Moiseev and Charles Ellis.
They made a significant contribution to the development of the structure, changing it from cantilever to suspended, finding the necessary engineering solutions to obtain a safe result. However, D. Strauss never recognized their merits, so the names of these architects are not even on the memorial plaque on the south tower of the bridge in San Francisco.
A certain difficulty was the financing of the project. After making a number of changes, its final cost was $ 35 million. It almost impossible to find sponsors in those years; the state also did not want to get involved in a dubious project.
The solution was to issue bonds for the required amount. The pledge was the farms, houses, commercial real estate of Strauss’s supporters. The last bond redeemed in 1971. Interest paid was nearly $ 39 million.
Construction of the Golden Gate Bridge began on January 5, 1933, and almost immediately the workers faced difficulties. During the erection of the foundations of the southern tower, soil instability discovered, so it taken to another place. It was possible to work in this part of the bay only during low tide, when there was no powerful current, which is about 20 minutes a day.
In December 1933, a storm destroyed the support. It took almost 4 months to repair it.
In November 1933, workers began building the tower from the Marin County side. According to various sources, they completed it in June or November 1934. In the same year, piers actively built on both sides of the bay. The tower from the San Francisco side erected from January to June 1935.
On November 18, 1936, two parts of the suspension span were connected exactly in the middle of the bridge. In the same year, workers installed the cable system.
In mid-April 1937, the laying of asphalt completed, and on May 27, the inauguration of the Golden Gate Bridge in San Francisco took place. On this day, about 200,000 pedestrians passed through it.
Safety measures during work
During the work, unprecedented security measures taken. When in the field of bridge construction there the death of one worker for 1 million dollars invested, D. Strauss decided to do everything to minimize the number of victims at the construction site.
- There was a categorical ban on risky stunts and tomfoolery on the jobsite. His violation followed by dismissal.
- Under the threat of dismissal, workers obliged to wear helmets. These modified miners’ helmets that Edward Ballard had worked on.
- Workers were provided with non-glare safety goggles and respiratory masks.
- A metal mesh stretched under the suspension part of the bridge, which during the construction kept 19 workers who fell from the structures. Its cost was $ 130,000.
Strauss showed some concern for the health of the workers. They give protective creams for their hands and face, developed a diet for dizziness at altitude, and even treated their hangover with cabbage brine.
A mobile medical aid station was deployed on the pier. Despite all the measures taken, 11 people died at the construction site in 4 years. Their names immortalized on a plaque on the south tower of the Golden Bridge in San Francisco.
Description of the Golden Gate in San Francisco
About 10 million people visit the Golden Gate Bridge annually as a landmark. They attracted not only by the picturesque landscapes, but also by the architectural features, the original color of the building, the unforgettable impressions of walking along the pedestrian zone at an altitude of 67 m above sea level.
The Golden Gate Bridge in San Francisco is a hanging structure that actually rests on the shores of the bay and two towers. The total length, including the approaches, is 2732 m, the length of the spans over the water (central and side) is 1966 m, the span between the towers is 1280 m.
The two towers of the bridge, 227 m high, serve as supports not only for the spans, but also for the two main cables. Their load on each tower is 56,000 tons! The ropes spun galvanized carbon steel. They fixed on supports using concrete counterweights. The diameter of one rope is 0.62 m, and the length is 2332 m.
250 pairs of vertical ropes stretched along the bridge every 15 m. They not only give an airy and elegant look to the structure, but also relieve up to 50% of the stress from the main cables.
The bridge divided into a six-lane carriageway and two pedestrian lanes on either side of it. At the same time, the number of lanes for car traffic changes during the day depending on the congestion. This happens automatically with the help of a special barrier set in 2015 for $ 30.3 million.
Design and lighting of the building
The bridge in San Francisco designed by Irving Morrow and his wife. It thanks to them that the world-famous building has the look that everyone used to.
In the factory, the towers painted with red lead-based paint. When they lifted for installation, Morrow sailed by on the ferry. At this point, he clearly understood how important the color of the bridge is in relation to the environment. Morrow slightly modified it, and the result was the famous original color of the building – International Orange .
For the design of the bridge, other colors also considered – black, gray, silver. After studying, the attracted artists, architects and even sculptors came to the conclusion that these tones distort the perception of the bridge and do not combine with the surrounding landscapes.
It was Irving Morrow who gave the bridge its characteristic Art Deco features:
- simplified the shape of pedestrian barriers;
- gave the lanterns an elegant curved shape;
- added relief to the surface of the towers in the form of vertical ribs;
- narrowed the tower portals upward.
The original design, developed by Strauss, was less attractive and lacking in graceful lines.
Back in 1935, Morrow developed a lighting scheme for the bridge. It was a different intensity of light coming from low pressure sodium lamps. In 1972, they replaced with high pressure lamps, saving on energy consumption. The towers illuminated only for the 50th anniversary of the building in 1987. It cost $ 1.2 million.
Today, the lighting system includes lights for main cables, roadways and sidewalks, decorative lighting for towers, aviation and navigation beacons.
Golden gate in numbers and facts
The operating Golden Gate Bridge amazes tourists not only with its appearance, but also with some statistical data, facts of its “biography”.
- In 1986, the total weight of the bridge with approaches and attachments was 894,500 tons.
- The weight of the two towers is 44,000 tons.
- The design is not static. Depending on the strength of the wind and the load on the central span, the bridge deviates laterally, up or down. The maximum lateral deflection reaches 8.4 m.
- The height of the towers above the roadway is 152 m.
- The spinning of the main ropes took 6 months and 9 days.
- In the entire history of its existence, the bridge closed only 3 times due to weather conditions. In 1951 – by 4 hours, in 1982 – by 3 hours, in 1983 – by 3 hours and 27 minutes.
- For short periods of time, traffic blocked due to the installation of a separation barrier, the president’s visits, and the repair of the suspension cable.
- The Golden Gate is the leader in the number of suicides in the world. During its existence, the number of people who jumped from it exceeded 1200 people. Today, there are special telephones on the bridge that suicides can use to call the crisis center.
- There is a kind of welcome center in front of the bridge. There you can learn the history of the construction of the building, buy souvenirs, relax and have a snack in a cafe.
- The bridge regularly tinted by a team of 34 painters. The international CMYK color formula is used: C (cyan) – 0%, M (magenta) – 69%, Y (yellow) – 100%, K (black) – 6%.
The pedestrian area is open at certain hours. You can only walk along the east side facing San Francisco. Cyclists and motorists can cross the bridge in both directions around the clock. Only vehicles heading south charged. There is a strict speed limit on the bridge. Traveling on scooters prohibited.
A visit to the Golden Gate of San Francisco is an unforgettable experience for most tourists. The unique building is beautiful both in the dark and in the daytime, both in fog and in clear weather.