Sydney Harbour Bridge: Sydney

The Sydney Harbour Bridge is a steel arch bridge across Sydney Harbour that carries rail, vehicular and pedestrian traffic between the Sydney central business district and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic image of both Sydney and Australia. The bridge is locally nicknamed "The Coathanger" because of its arch-based design.

The bridge was designed and built by Dorman Long and Co Ltd, Middlesbrough Teesside and Cleveland Bridge, Darlington, County Durham and opened in 1932. Until 1967 it was the city's tallest structure. According to Guinness World Records, it is the world's widest long-span bridge and it is tallest steel arch bridge, measuring 134 metres (429.6 ft) from top to water level. It is also the fifth-longest spanning-arch bridge in the world.

The southern (CBD) bridge end is located at Millers Point in The Rocks area, and the northern end at Milsons Point in the lower North Shore area. It carries six lanes of road traffic on its main roadway, two lanes of road traffic (formerly two tram tracks) and a footpath on its eastern side, and two railway tracks and a bicycle path along its western side, being 305 mm (1 ft) larger than the east side.

The main roadway across the bridge is known as Bradfield Highway, Sydney, and is about 2.4 km (1.5 miles) long, making it one of the shortest highways in Australia. (The shortest, also called the Bradfield Highway, is found on the Story Bridge in Brisbane).

The Sydney Harbour Bridge is not completely stationary. It can rise or fall up to 18 cm depending on whether it is hot or cold due to the steel expanding or contracting

Tsing Ma Bridge: Hong Kong

The Tsing Ma Bridge is a bridge in Hong Kong. It is the world's seventh-longest span suspension bridge. The bridge was named after two of the islands at its ends, namely Tsing Yi and Ma Wan . It has two decks and carries both road and rail traffic, which also makes it the largest suspension bridge of this type. The bridge has a main span of 1,377 metres (4,518 ft) and a height of 206 metres (676 ft). The span is the largest of all bridges in the world carrying rail traffic.

The 41 metres (135 ft) wide bridge deck carries six lanes of automobile traffic, with 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. Though road traffic would need to be closed in that case, trains could still get through in either direction.

Oresund Bridge: Öresund strait

The Øresund or Öresund Bridge is a combined two-track rail and four-lane road bridge-tunnel across the Öresund strait. It is the longest combined road and rail bridge in Europe and connects the two metropolitan areas of the Öresund Region: the Danish capital of Copenhagen and the Swedish city of Malmö. The international European route E20 runs across the bridge and through the tunnel via the two lane motorway, as does the Öresund Railway Line. The bridge is the longest border crossing bridge in the world, but due to the Schengen Agreement, there are no passport controls. However there are frequent random customs control checks at the toll booths on the Swedish side for those entering Sweden, but not when entering Denmark.

The bridge has one of the longest cable-stayed main spans in the world at 490 metres (1,608 ft). The height of the highest pillar is 204 metres (669 ft). The total length of the bridge is 7,845 metres (25,738 ft), which is approximately half the distance between the Swedish and Danish landmasses, and its weight is 82,000 tonnes. The border is located 2.5 km (1.6 mi) from the western end and 5.3 km (3.3 mi) from the eastern end of the bridge. On the bridge, the two rail-tracks are beneath the four road lanes. The bridge has a vertical clearance of 57 metres (187 ft), although most boat traffic across Oresund still passes over the Drogden strait (where the tunnel lies). The bridge's architecture is by Georg Rotne, with structural design made by Arup.

Tower Bridge: London, England

Tower Bridge is a combined bascule and suspension bridge in London, England, over the River Thames. It is close to the Tower of London, which gives it its name. It has become an iconic symbol of London. Tower Bridge is one of several London bridges owned and maintained by the City Bridge Trust, a charitable trust overseen by the City of London Corporation.

The bridge consists of two towers which are tied together at the upper level by means of two horizontal walkways which are designed to withstand the horizontal forces exerted by the suspended sections of the bridge on the land-ward sides of the towers. The vertical component of the forces in the suspended sections and the vertical reactions of the two walkways are carried by the two robust towers. The bascule pivots and operating machinery are housed in the base of each tower. Its present colour dates from 1977 when it was painted red, white and blue for the Queen's Silver Jubilee. Originally it was painted a chocolate brown colour.

Tower Bridge is sometimes mistakenly referred to as London Bridge, which is actually the next bridge upstream. A popular urban legend is that in 1968, Robert McCulloch, the purchaser of the old London Bridge that was later shipped to Lake Havasu City, Arizona, believed that he was in fact buying Tower Bridge. This was denied by McCulloch himself and has been debunked by Ivan Luckin, the seller of the bridge.

Golden Gate Bridge: San Francisco, USA

The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the opening of the San Francisco Bay onto the Pacific Ocean. As part of both U.S. Route 101 and California State Route 1, it connects the city of San Francisco on the northern tip of the San Francisco Peninsula to Marin County. The Golden Gate Bridge was the longest suspension bridge span in the world when it was completed during the year 1937, and has become an internationally recognized symbol of San Francisco and California. Since its completion, the span length has been surpassed by eight other bridges. It still has the second longest suspension bridge main span in the United States, after the Verrazano-Narrows Bridge in New York City. In 2007, it was ranked fifth on the List of America's Favorite Architecture by the American Institute of Architects.

Strauss was chief engineer in charge of overall design and construction of the bridge project. However, because he had little understanding or experience with cable-suspension designs, responsibility for much of the engineering and architecture fell on other experts.

Irving Morrow, a relatively unknown residential architect, designed the overall shape of the bridge towers, the lighting scheme, and Art Deco elements such as the streetlights, railing, and walkways. The famous International Orange color was originally used as a sealant for the bridge. Many locals persuaded Morrow to paint the bridge in the vibrant orange color instead of the standard silver or gray, and the color has been kept ever since.

Senior engineer Charles Alton Ellis, collaborating remotely with famed bridge designer Leon Moisseiff, was the principal engineer of the project. Moisseiff produced the basic structural design, introducing his "deflection theory" by which a thin, flexible roadway would flex in the wind, greatly reducing stress by transmitting forces via suspension cables to the bridge towers. Although the Golden Gate Bridge design has proved sound, a later Moisseiff design, the original Tacoma Narrows Bridge, collapsed in a strong windstorm soon after it was completed, because of an unexpected aeroelastic flutter.

With an eye toward self-promotion and posterity, Strauss downplayed the contributions of his collaborators who, despite receiving little recognition or compensation, are largely responsible for the final form of the bridge. He succeeded in having himself credited as the person most responsible for the design and vision of the bridge. Only much later were the contributions of the others on the design team properly appreciated. In May 2007, the Golden Gate Bridge district issued a formal report on 70 years of stewardship of the famous bridge and decided to right an old wrong by giving Ellis major credit for the design of the bridge.

Ponte Vecchio: Florence, Italy

The Ponte Vecchio is a Medieval bridge over the Arno River, in Florence, Italy, noted for still having shops built along it, as was once common. Butchers initially occupied the shops; the present tenants are jewelers, art dealers and souvenir sellers. It has been described as Europe's oldest wholly-stone, closed-spandrel segmental arch bridge, but there are far older segmental arch bridges such as Alconétar Bridge. The Ponte Vecchio's two neighbouring bridges are the Ponte Santa Trinità and the Ponte alle Grazie.

Kintaikyo: Iwakuni, Japan

Possibly one of the most unlucky bridges in the world, Kintaikyo was reconstructed in the town of Iwakuni in 1673 after every other attempt to cross the Nishiki River via bridge had been foiled by seasonal flooding. Remarkably, the five wooden arches remained intact right up to 1950 when a typhoon finally destroyed them. However, intent on not being beaten, the bridge was again reconstructed three years later and is still crossable today

Erasmusbrug: Rotterdam, Netherlands

The Erasmusbrug ("Erasmus Bridge") is a cable stayed bridge across the Nieuwe Maas river, linking the northern and southern halves of the city of Rotterdam, Netherlands.

The Erasmusbrug was designed by Ben van Berkel and completed in 1996. The 808 metre long bridge has a 139 metre-high asymmetrical pylon, earning the bridge its nickname of "The Swan".

The southern span of the bridge has a 89 metre long bascule bridge for ships that cannot pass under the bridge. The bascule bridge is the largest and heaviest in West Europe and has the largest panel of its type in the world.

The bridge was officially opened by Queen Beatrix on September 6, 1996, having cost 165 million Dutch guilders (about 75 million euro) to construct. Shortly after the bridge opened to traffic in October 1996, it was discovered the bridge would swing under particularly strong wind conditions. To reduce the trembling, stronger shock dampers were installed.

The bridge featured in the 1998 Jackie Chan film Who Am I?. In 2005 several planes flew underneath the bridge as part of the "Red Bull Air Race".

In 2005, the bridge served as the backdrop for a performance by DJ Tiësto titled "Tiësto @ The Bridge, Rotterdam". The performance featured fire fighting ships spraying jets of water into the air in front of the bridge, a fireworks barge launching fireworks beside the bridge, and multi coloured spot/search lights attached to the bridge itself.

Bering Straits Bridge: Bering Straits

The proposed Bering Straits bridge will hopefully act as a transcontinental link by land, connecting Asia, Africa and Europe with North and South America. Possible locations for the bridge have been suggested, with Cape Dezhnev, Chukotka, and Cape Prince of Wales, Alaska looking the most likely sources. Some suggestions have called for a series of three bridges spanning over 50 miles in total, although the tough Arctic conditions which make the area so notorious will almost definitely hinder construction and maintenance.

The Bering Strait is a sea strait between Cape Dezhnev, Chukotka Autonomous Okrug, the easternmost point (169°43' W) of the Asian continent and Cape Prince of Wales, Alaska, the westernmost point (168°05' W) of the North American continent, with latitude of about 65° 40' north, slightly south of the polar circle. It is one of the biggest of its kind.

The Bering Strait has been the subject of scientific speculation that humans migrated from Asia to the North American continent across a land bridge formed by lower ocean levels in the distant past exposing a ridge beneath the ocean. At periods when the oceans were lower, such as when glaciers locked up vast amounts of water, the exposed ridge would have allowed humans to simply walk from Siberia to Alaska, thus populating North and South America thousands of years ago.

Gateshead Millennium Bridge: Gateshead, England

The Gateshead Millennium Bridge is a pedestrian and cyclist tilt bridge spanning the River Tyne in England between Gateshead on the south bank, and the Quayside of Newcastle upon Tyne on the north bank. The award-winning structure was conceived and designed by architects Wilkinson Eyre and structural engineers Gifford. The bridge is often referred to as the 'Winking Eye Bridge' due to its elliptical shape and its rotational movement.

The bridge was lifted into place in one piece by the Asian Hercules II, one of the world's largest floating cranes, on 20 November 2000. It was opened to the public on 17 September 2001, and was dedicated by Queen Elizabeth II on 7 May 2002. The bridge, which cost £22m to build, was part funded by the Millennium Commission and European Regional Development Fund. It was built by Volker Stevin.

Already acclaimed worldwide for its physical and aesthetic beauty, it has fast become a significant tourist attraction in its own right. The bridge was the focus of a Spencer Tunick installation on 17 July 2005.

Six 45 cm diameter Hydraulic rams rotate the bridge back on large bearings to allow small ships and boats to pass underneath. The bridge takes as little as 4.5 minutes to rotate through the full 40° from closed to open, depending on wind speed. Its appearance during this manoeuvre has led to it being nicknamed the "Blinking Eye Bridge".

The bridge has operated reliably since construction, opening to allow river traffic to pass. It also opens periodically for sightseers and for major events such as the Northumbrian Water University Boat Race and the Cutty Sark Tall Ships' Race. Its reputation was untarnished until October 2004 when the failure of a £200 circuit board prevented the bridge from opening.

The construction of the bridge won the architects Wilkinson Eyre the 2002 Royal Institute of British Architects Stirling Prize and won Gifford the 2003 IStructE Supreme Award. In winning the Stirling Prize, Wilkinson Eyre became the first, and so far the only, firm of architects to retain British architecture's most prestigious prize — they won the 2001 prize for the Magna Science Adventure Centre. In 2005, the bridge received the Outstanding Structure Award from International Association for Bridge and Structural Engineering (IABSE).

Fehmarn Belt Bridge, Baltic Sea

The Fehmarn Belt bridge is a project to connect the German island of Fehmarn with the Danish island of Lolland with a bridge crossing the 11 mi wide Fehmarn Belt in the Baltic Sea. It is expected to be completed in 2018.

The bridge will have a total length of approximately 19 km (12 mi) and will be constructed as a triple-span cable-stayed bridge with each of the three spans being 724 metres (2,375 ft) long. The four pillars carrying the bridge will be approximately 280 m (919 ft) tall. The vertical clearance will be 65 m (213 ft) allowing sea traffic with large ships to and from the Baltic Sea to go beneath it.

The design involves four road lanes and two rail tracks. The latest cost estimate is DKK 42 bn (EUR 5 bn)

This cost includes EUR 1.5 bn for other improvements such as electrifying and rebuilding 99 mi of railway from single to double track. New bridges at Fehmarn Sound and Storstrøm would be needed. However, according to the treaty the Fehmarn Sound bridge need not be replaced, and the Storstrøm Bridge will also not be replaced. Also, the German double track construction will be delayed by seven years according to the treaty.

The bridge and the double track will shorten the rail journey from Hamburg to Copenhagen from 4¾ to 3-3¼ hours. According to plans there will be one passenger train and two freight trains over the bridge per direction per hour. There will be congestion and delays on the German side with this traffic if the double track construction is delayed.

The road between Copenhagen and Hamburg is already motorway except for 25 km in Germany . The rest is a single carriageway expressway. It shall be widened to a motorway except the Fehmarn Sound . It is possible that it will be delayed much further since the forecasted AADT, 9000 vehicles, does not make a four-lane road necessary. There is no penalty in the treaty for delayed construction.

The project is comparable to the Øresund Bridge, the Great Belt Bridge or plans for the Strait of Messina Bridge and will be the largest planned infrastructure project in Northern Europe. The route is the main connection between Hamburg, and Copenhagen/Malmö as well as further destinations in Scandinavia.

The Millau Viaduct: Tarn Valley, France

The Millau Viaduct is a large cable-stayed road-bridge that spans the valley of the river Tarn near Millau in southern France. Designed by the structural engineer Michel Virlogeux and British architect Norman Foster, it is the tallest vehicular bridge in the world, with one mast's summit at 1,125 ft — slightly taller than the Eiffel Tower and only 125 ft shorter than the Empire State Building. The viaduct is part of the A75-A71 autoroute axis from Paris to Béziers. It was formally dedicated on 14 December 2004, inaugurated the day after and opened to traffic two days later. The bridge won the 2006 IABSE Outstanding Structure Award.

The Millau Viaduct consists of an eight-span steel roadway supported by seven concrete pylons. The roadway weighs 36,000 tonnes and is 2,460 m (8,100 ft) long, measuring 32 m (100 ft) wide by 4.2 m (14 ft) deep, making it the world's longest cable-stayed deck. The six central spans each measure 342 m 1,120 ft with the two outer spans measuring 204 m 670 ft. The roadway has a slope of 3% descending from south to north, and curves in a plane section with a 20 km 12 mi radius to give drivers better visibility. The pylons range in height from 250 ft to 810 ft, and taper in their longitudinal section from 24.5 m 80 ft at the base to 36 ft at the deck. Each pylon is composed of 16 framework sections, each weighing 2,230 tons. These sections were assembled on site from pieces of 60 tons, 4 m 13 ft wide and 56 ft long, made in factories in Lauterbourg and Fos-sur-Mer by Eiffage. The pylons each support 97 m 320 ft tall masts.

The pylons were assembled first, together with some intermediate temporary pylons, before the decks were slid out across the piers by satellite-guided hydraulic rams that moved the deck 600 mm every 4 minutes. Then the masts were driven over the new deck, erected on top of the pylons, connected to the deck and the temporary pylons removed.

Construction began on 10 October 2001 and was intended to take three years, but weather conditions put work on the bridge behind schedule. A revised schedule aimed for the bridge to be opened in January 2005. The viaduct was inaugurated by President Chirac on 14 December 2004 to open for traffic on 16 December, several weeks ahead of the revised schedule.

The construction of the bridge was depicted in an episode of the National Geographic Channel MegaStructures series, as well as Discovery Channel's Extreme Engineering