- Education and Science
Bridges Of The World
Bridges, the idols of the engineering world, influence the cultural development, lifestyles and the environment in countless ways. Bridges shape skylines. Imagine San Francisco without the Golden Gate Bridge, or Manhattan without the Brooklyn Bridge.
Travel to the far reaching corners of the world and discover an intriguing diversity of bridges. Nowadays, bridges are considered much more than their obvious purpose of crossing awkward stretches of water or land, they have also become iconic city's so called landmarks and tourist attraction.
It's almost impossible that one could imagine visiting Sydney without a trip or a quick visit to the Harbour Bridge or London without visiting the Tower, Venice without Rialto or San Francisco without visiting Golden Gate. From a pictorial stone bridge spanning a Venetian canal, to the Brisbane Bridge of Australia reflecting its shimmering lights onto the river below, to the sweeping expanse of the Mackinac Bridge in Michigan, to a wooden foot bridge precariously perched over a rushing river in Yugoslavia, you will be filled with wonder at the array of bridges man has constructed.
An amazing fact about the construction of the Golden Gate Bridge was that it seemed like an impossible task 100 years ago, as it would have to withstand the region's brutal winds and tide. It was also pointed out that in the heart of the region is the earthquake zone. It is estimated that around nine million people from all over the world visit the bridge each year. Tower Bridge, often mistakenly called London Bridge, is another must see tourist spot.
Let's take a ride around the world and get to know about a few of the famous bridges along with their specifications.
Tsing Ma, Hong Kong
Height (of pylons): 206m
Tsing Ma Bridge has become a favourite scenic spot as well as a famous landmark.
The Tsing Ma Gigantic Bridge stretching from Tsing Yi Isle to Ma Wan (Bay), 22,000 metres long, is the world's sixth largest suspension bridge, and the longest suspension bridge for both vehicle and railway purposes in the world. The Tsing Ma Bridge links Tsing Yi Island on the east to Ma Wan Island on the west over Ma Wan Channel. Mott MacDonald designed the bridge. From the Scenery Viewing Terrace, one can see the Ting Kau Bridge, Linking Tsing Yi and Tsuen Wun, totalling 1,178 metres long, the longest triplex-towered shape cable bridge of the world.
The 41 metres wide bridge deck carries six lanes of automobile traffic, three lanes in each direction. The lower level contains two rail tracks. There are also two sheltered carriageways on the lower deck for maintenance access and as backup for traffic when particularly severe typhoons strike Hong Kong.
Akashi Kaikyo, Japan
One of the most impressive feats of modern engineering, the Akashi Kaikyo Bridge in Japan is the longest, tallest, and most expensive suspension bridge ever constructed. The bridge crosses the Akashi Strait; it links Maiko in Kobe and Iwaya on Awaji Island as part of the Honshû-Shikoku Highway. The bridge has three spans. The central span is 1,991 metres, with the two other sections 960 metres each.
The bridge is 3,911 metres long overall. The Akashi Straits is one of the busiest sea lanes in the world with over a thousand ships per day travelling through it. The bridge was opened for traffic on April 5, 1998 by the Crown Prince and Princess of Japan.
The Ponte di Rialto "Rialto Bridge" is the true heart of Venice. This is the most famous bridge in all of Venice; the most ancient bridge connecting the two parts of the Canal Grande (Grand Canal). Many designers from around the world were considered for the bridge and the present stone bridge, a single span designed by Antonio da Ponte, was finally completed in 1591.The Rialto Bridge's 24-feet arch was designed to allow passage of galleys, and the massive structure was built on some 12,000 wooden pilings that still support the bridge more than 400 years later.
The wooden structure was finally dismantled and replaced by a marble version only at the end of the 16th century. The first private bank was opened and offices connected with trade and sea traffic were established in 1157.
Tower Bridge, London
Height (of foot bridges): 43m
The Tower Bridge, over the River Thames in London, is combined bascule and suspension bridge. It is the most distinctive of London's bridges and its construction was a masterly engineering achievement. Construction started in 1886 and took eight years, employing five major contractors and 432 construction workers.
The building of the Tower Bridge came about because the cross-Thames traffic had far outstripped the capacity of the existing bridges. The bridge was inaugrated by the then Prince of Wales, the future King Edward VII, and his wife, Alexandra of Denmark on June 30, 1894.
In 1994, Tower Bridge became available to hire for parties and receptions. It was a hydraulically operated bridge, using steam to power the enormous pumping engines. The whole process of opening the bascules, allowing a ship to pass and bringing them down again for the resumption of road traffic takes only five minutes. The high-level walkways, which were designed so that the public could still cross the bridge when it was raised, were closed down due to lack of use. Most people preferred to wait at the bottom and watch the bascules rise up.
Sydney Harbour Bridge, Australia
The Sydney Harbour Bridge is one of Sydney's most famous landmarks. Prior to the bridge being built, the only links between the city centre in the south and the residential north were by ferry or by a 20 kilometre road route that involved five bridge crossings. The 75th anniversary of this iconic bridge was celebrated on March 18, 2007. The dramatic water vista of the bridge together with the nearby Sydney Opera House is an iconic image of both Sydney and Australia.
Linking the city with North Sydney, it carries eight lanes of road traffic and two railway tracks which form part of the city's rail suburban network. The bridge was designed to carry six lanes of road traffic, flanked by two railway tracks and a footpath on each side. This is the widest long-span bridge in the world and is the largest steel arch bridge with the top of the bridge standing 134 metres above the harbour. The bridge was formally opened by cutting a ribbon at its southern end on March 19, 1932 by the premier of NSW, Jack Lang.
Brooklyn Bridge, New York
The Brooklyn Bridge, originally the New York and Brooklyn Bridge, is one of the oldest suspension bridges over the East River connecting the New York City boroughs of Manhattan and Brooklyn. The Brooklyn Bridge is 6,016 feet long, spanning the East river and allowing transportation from Manhattan Island to the Western Shore of Brooklyn. The bridge was designed by John A. Roebling who died before construction began. Work was completed by his son, Washington Roebling and Washington's wife, Emily. John Roebling's plan was approved after 60 years of political, financial and technical discussions including a six lane tunnel proposal in the 1830s. On completion, it was the largest suspension bridge in the world and the first steel-wire suspension bridge.
Since its opening, it has become an iconic part of the New York Skyline. On May 24, 1883, with schools and businesses closed, the Brooklyn Bridge, also referred to as the "Great East River Bridge", was opened. Scores of people attended this spectacular ribbon cutting event. Over 100 years later, its renowned beauty and stature is still admired by many New Yorkers and tourists alike.
Mackinac Bridge, Michigan
The Mackinac Bridge celebrated its 50th year on July 27-28, 2007. The Mackinac Bridge connects the upper and lower peninsulas of Michigan over the five mile wide Straits of Mackinac where Lake Michigan and Lake Huron meet.
This bridge was designed by David B. Steinman. Also known as the "Mighty Mac", this engineering marvel is five miles long and, anchor block to anchor block, holds the record as the longest suspension bridge in the world. The Mackinac Bridge is the longest two tower suspension bridge between anchorages 2,626 metres in the Western Hemisphere. The Authority consulted with three of the world's experts in long span bridge engineering and traffic consultation for advice on physical and financial feasibility. The bridge was opened to traffic on November 1, 1957.