Thursday 26 April 2012

Hoover Dam,Las Vegas

Hoover Dam

Hoover Dam
There would be no Las Vegas as we know it without Hoover Dam. Certainly, the neon and glitz that we know and love would not exist. In fact, the growth of the entire Southwest can be tied directly to the electricity created by the dam.
Until Hoover Dam was built, much of the southwestern United States was plagued by two natural problems: parched, sandy terrain that lacked irrigation for most of the year and extensive flooding in spring and early summer, when the mighty Colorado River, fed by melting snow from its source in the Rocky Mountains, overflowed its banks and destroyed crops, lives, and property. On the positive side, raging unchecked over eons, the river's turbulent, rushing waters carved the Grand Canyon.
In 1928, prodded by the seven states through which the river runs during the course of its 1,400-mile journey to the Gulf of California, Congress authorized construction of a dam at Boulder Canyon (later moved to Black Canyon). The Senate's declaration of intention states, "A mighty river, now a source of destruction, is to be curbed and put to work in the interests of society." Construction began in 1931. Because of its vast scope and the unprecedented problems posed in its realization, the project generated significant advances in many areas of machinery production, engineering, and construction. An army of more than 5,200 laborers was assembled, and work proceeded 24 hours a day. Completed in 1936, 2 years ahead of schedule and $15 million under budget (it is, no doubt, a Wonder of the Modern Fiscal World), the dam stopped the annual floods and conserved water for irrigation, industry, and domestic uses. Equally important, it became one of the world's major electrical-generating plants, providing low-cost, pollution-free hydroelectric power to a score of surrounding communities. Hoover Dam's $165-million cost has been repaid with interest by the sale of inexpensive power to a number of California cities and the states of Arizona and Nevada. The dam is a government project that paid for itself -- a feat almost as awe-inspiring as its engineering.
The dam itself is a massive curved wall, 660 feet thick at the bottom, tapering to 45 feet where a road crosses it at the top. It towers 726 feet above bedrock (about the height of a 60-story skyscraper) and acts as a plug between the canyon walls to hold back up to 9.2 trillion gallons of water in Lake Mead, the reservoir created by its construction. Four concrete intake towers on the lake side drop the water down about 600 feet to drive turbines and create power, after which the water spills out into the river and continues south.
All the architecture is on a grand scale, and the design has beautiful Art Deco elements, unusual in an engineering project. Note, for instance, the monumental 30-foot bronze sculpture, Winged Figures of the Republic, flanking a 142-foot flagpole at the Nevada entrance. According to its creator, Oskar Hansen, the sculpture symbolizes "the immutable calm of intellectual resolution, and the enormous power of trained physical strength, equally enthroned in placid triumph of scientific achievement."
Seven miles northwest of the dam on U.S. 93, you'll pass through Boulder City, which was built to house managerial and construction workers. Sweltering summer heat (many days it is 125°F/52°C) ruled out a campsite by the dam. The higher elevation of Boulder City offered lower temperatures. The city emerged within a single year, turning a desert wasteland into a community of 6,000. By 1934, it was Nevada's third-largest town.

 
Getting There 
 Drive east on Flamingo Road or Tropicana Avenue to U.S. 515 S, which automatically turns into I-93 S and takes you right to the dam. This involves a dramatic drive as you go through Boulder City and come over a rise, and Lake Mead suddenly appears spread out before you. It's a beautiful sight. At about this point, the road narrows to two lanes, and traffic can slow considerably. After the 2010 opening of a bypass bridge (dramatic on its own for its soaring height over the canyon), vehicles no longer pass directly over the bridge to get from Nevada to Arizona, but despite hopes that the bypass would make the commute better, it hasn't helped much. On a normal day, getting to the dam will take about an hour.
Go past the turnoff to Lake Mead to Nevada State Route 172, the well-marked Hoover Dam Access Road. As you near the dam, you'll see a five-story parking structure tucked into the canyon wall on your left. Park here ($7 charge) and take the elevators or stairs to the walkway leading to the visitor center.
If you would rather go on an organized tour, check out Gray Line (tel. 800/634-6579; www.grayline.com), which offers a half-day tour of the dam from $60 or a daylong tour that includes a paddleboat cruise of Lake Mead and a tour of the Ethel M Chocolate factory from $92.
Inside image
hoover dam section

construction image

dam Statistics - Hoover Facts

  1. 1,244 feet wide (379 m)
  2. 660 feet (203 m) thick at the base
  3. 45 feet (13 m) thick at the top
  4. $165 million dollars to build
  5. 4.5 years to build
  6. 4.4 million yards of concrete used for construction
  7. March 1931 building began
  8. September 30, 1935 President Franklin D. Roosevelt dedicated the completed dam

powerhouse

  1. 17 generators
  2. 4+ billion kilowatt hours produced each year
  3. 10 acres of floor space

power used by:

  1. 56% California
  2. 25% Nevada
  3. 19% Arizona

lake Mead

  1. 6.5 years to fill (A slow filling process was required to lessen the pressure change on the dam and to help prevent small earthquakes due to land settlement.)
  2. 589 feet (181 m) at the deepest point
  3. 247 square miles in size
  4. 110 miles (176 km) long
  5. Named after Dr. Elwood Mead, Commissioner of the Bureau of Reclamation (1924 - 1936)
  6. Largest man made reservoir in the United States
Tag -Hoover Dam construction

Eiffel Tower


eiffel tower

                              the eiffel tower

where is the eiffel tower

 
 eiffel tower ticket

The Eiffel Tower is the most visited paid-monument in the world. Its popularity makes the Eiffel Tower advanced tickets essential to avoid the long queues. By booking your Eiffel Tower ticket online with Local Paris Tours you can make the most of your time in Paris.

The Eiffel Tower was built as a temporary structure for the 1889 World Fair. Standing at 324 meters it was such a success the fair officials decided not to demolish the structure. Now, the Eiffel Tower is one of the world’s most recognizable landmarks.

 


pictures of eiffel tower

eiffel tower height

The Eiffel Tower was built for the International Exhibition of Paris of 1889 commemorating the centenary of the French Revolution. The Prince of Wales, later King Edward VII of England, opened the tower. Of the 700 proposals submitted in a design competition, Gustave Eiffel's was unanimously chosen. However it was not accepted by all at first, and a petition of 300 names - including those of Maupassant, Emile Zola, Charles Garnier (architect of the Opéra Garnier), and Dumas the Younger - protested its construction. At 300 meters (320.75 m including antenna), and 7,000 tons, it was the world's tallest building until 1930. Other statistics include:
  1. 2.5 million rivets
  2. 300 steel workers, and 2 years (1887-1889) to construct it.
  3. Sway of at most 12 cm in high winds.
  4. Height varies up to 15 cm depending on temperature.
  5. 15,000 iron pieces (excluding rivets). 40 tons of paint. 1652 steps to the top.
In 1889, Gustave Eiffel began to fit the peak of the tower as an observation station to measure the speed of wind. He also encouraged several scientific experiments including Foucault's giant pendulum, a mercury barometer and the first experiment of radio transmission. In 1898, Eugene Ducretet at the Pantheon, received signals from the tower.

 After Gustave Eiffel experiments in the field of meterology, he begun to look at the effects of wind and air resistance, the science that would later be termed aerodynamics, which has become a large part of both military and commercial aviation as well as rocket technology. Gustave Eiffel imagined an automatic device sliding along a cable that was stretched between the ground and the second floor of the Eiffel Tower. 
  
eiffel tower restaurant 



 

Reservations
(702) 948-6937
 
Cuisine
Seafood/Steakhouse (Upscale Dining)
 
Hours Of Operation
Lunch 11:30 AM - 2:00 PM Monday - Friday
Brunch 11:00 AM - 2:00 PM Saturday and Sunday
Dinner 5:00 PM - 10:30 PM Sunday - Thursday
5:00 PM - 11:00 PM Friday and Saturday

Dress Code
Business Casual/Semi Formal
 
Menus
Features
  • Classical French cuisine
  • Breathtaking view of the Strip
  • Full bar
Executive Chef
Chef J Joho
 
material

The wrought iron structure of the Eiffel Tower weighs 7,300 tonnes, while the entire structure, including non-metal components, is approximately 10,000 tonnes. As a demonstration of the economy of design, if the 7,300 tonnes of the metal structure were melted down it would fill the 125-metre-square base to a depth of only 6 cm (2.36 in), assuming the density of the metal to be 7.8 tonnes per cubic metre. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18 cm (7.1 in) because of thermal expansion of the metal on the side facing the sun.

interior
eiffel tower interior








wind considerations

At the time the tower was built many people were shocked by its daring shape. Eiffel was criticised for the design and accused of trying to create something artistic, or inartistic according to the viewer, without regard to engineering. Eiffel and his engineers, however, as experienced bridge builders, understood the importance of wind forces and knew that if they were going to build the tallest structure in the world they had to be certain it would withstand the wind. In an interview reported in the newspaper Le Temps, Eiffel said:
Now to what phenomenon did I give primary concern in designing the Tower? It was wind resistance. Well then! I hold that the curvature of the monument's four outer edges, which is as mathematical calculation dictated it should be  will give a great impression of strength and beauty, for it will reveal to the eyes of the observer the boldness of the design as a whole.
 Researchers have found that Eiffel used empirical and graphical methods accounting for the effects of wind rather than a specific mathematical formula. Careful examination of the tower shows a basically exponential shape; actually two different exponentials, the lower section overdesigned to ensure resistance to wind forces. Several mathematical explanations have been proposed over the years for the success of the design; the most recent is described as a nonlinear integral equation based on counterbalancing the wind pressure on any point on the tower with the tension between the construction elements at that point.As a demonstration of the tower's effectiveness in wind resistance, it sways only 6–7 cm (2–3 in) in the wind.

Maintenance

Maintenance of the tower includes applying 50 to 60 tonnes of paint every seven years to protect it from rust. The height of the Eiffel Tower varies by 15 cm due to temperature.

Due to the effect of Thermal Expansion, the Eiffel Tower is upto 15cm taller in summer

economics

The American TV show Pricing the Priceless speculates that in 2011 the tower would cost about $480,000,000 to build, that the land under the tower is worth $350,000,000, and that the scrap value of the tower is worth $3,500,000. The TV show estimates the tower makes a profit of about $29,000,000 per year, though it is unlikely that the Eiffel Tower is managed so as to maximize profit.
It costs $5,300,000 to repaint the tower, which is done once every seven years. The electric bill is $400,000 per year for 7.5 million kilowatt-hours.
The Tokey Tower in Japan is a very similar structure of very similar size. It was finished in 1958 at a final cost of ¥2.8 billion ($8.4 million in 1958).

construction

Work on the foundations started in January 1887. Those for the east and south legs were straightforward, each leg resting on four 2 m (6.6 ft) concrete slabs, one for each of the principal girders of each leg but the other two, being closer to the river Seine were more complicated: each slab needed two piles installed by using compressed-air caissons 15 m (49 ft) long and 6 m (20 ft) in diameter driven to a depth of 22 m (72 ft) to support the concrete slabs, which were 6 m (20 ft) thick. Each of these slabs supported a block built of limestone each with an inclined top to bear a supporting shoe for the ironwork. Each shoe was anchored into the stonework by a pair of bolts 10 cm (4 in) in diameter and 7.5 m (25 ft) long. The foundations were complete by 30 June and the erection of the ironwork began. The very visible work on-site was complemented by the enormous amount of exacting preparatory work that was entailed: the drawing office produced 1,700 general drawings and 3,629 detailed drawings of the 18,038 different parts needed: the The task of drawing the components was complicated by the complex angles involved in the design and the degree of precision required: the position of rivet holes was specified to within 0.1 mm (0.04 in) and angles worked out to one second of arc. The finished components, some already riveted together into sub-assemblies, arrived on horse-drawn carts from the factory in the nearby Parisian suburb of  were first bolted together, the bolts being replaced by rivets as construction progressed. No drilling or shaping was done on site: if any part did not fit it was sent back to the factory for alteration. In all there were 18,038 pieces of wrought iron using two and a half million rivets.
At first the legs were constructed as cantilivers but about halfway to the first level construction was paused in order to construct a substantial timber scaffold. This caused a renewal of the concerns about the structural soundness of the project, and senstional headlines such as "Eiffel Suicide!" and "Gustave Eiffel has gone mad: he has been confined in an Asylum" appeared in the popular press. At this stage a small "creeper" crane was installed in each leg, designed to move up the tower as construction progressed and making use of the guides for the elevators which were to be fitted in each leg. The critical stage of joining the four legs at the first level was complete by March 1888. Although the metalwork had been prepared with the utmost precision, provision had been made to carry out small adjustments in order to precisly align the legs: hydraulic jackwere fitted to the shoes at the base of each leg, each capable of exerting a force of 800 tonnes, and in addition the legs had been intentionally constructed at a slightly steeper angle than necessary, being supported by sand boxes on the scaffold.
No more than three hundred workers were employed on site, and because Eiffel took safety precautions, including the use of movable stagings, guard-rails and screens, only one man died during construction.

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