A world of technical wonders
A symbol of Roman architecture
It’s 2,000 years old and still standing tall. The Pont du Gard in the Provence region of France is an impressive example of Roman architectural excellence. Its construction that was completed in the first century AD is said to have taken three years. More than 1,000 people are supposed to have been involved in building the bridge. The Pont du Gard is the key structure of a fresh water connection between today’s cities of Uzès and Nîmes. The two cities are only 20 kilometers (12 miles) apart from each other as the crow flies but the aqueduct bridge must overcome or circumvent several geographic obstacles, so covering more than twice that distance. The challenge lay in the merely 17 meters (56 feet) of elevation difference between the source in Uzès and the city of Nîmes, resulting in a downward slope of only 34 centimeters (13.4 inches) per kilometer (0.6 miles). The aqueduct precisely complies with that on the entire 50-kilometer (31-mile) distance it covers – despite the need for mountains to be drilled through and river valleys to be overcome. A brilliant feat!
Progress through iron
Elevators are part of many people’s everyday lives. In Lisbon, one of them even connects several neighborhoods. The Elevador de Santa Justa overcomes 45 vertical meters (148 vertical feet) between the lower district of Baixa and the Chiado and Bairro Alto neighborhoods in the upper part of the city. The elevator pays homage to iron, the construction material used around the year of 1900. Iron symbolized progress and enabled masterfully crafted ornaments in architectural projects. Responsible for the elevator’s construction from 1900 to 1902 was Raoul Mesnier de Ponsard, a student of Gustave Eiffel’s. That explains some similarities with the famous Eiffel Tower in Paris. Each of the two glazed elevator cars that have been preserved in their original condition can accommodate 24 people. However, during the ride, which costs more than five euros, they can see hardly more than the cast-iron structure. After arriving at the top terminal, visitors reach the upper part of the city via a footbridge. There are two additional floors above the exit that must be accessed via a staircase. The first floor houses the engine room in which steam engines initially moved the cars, followed in 1907 by electric motors. From the observation deck atop the engine room visitors enjoy a view of the lower part of town extending all the way to the opposite fortress Castelo de São Jorge – magnífico.
A living monument of industrial culture
Mammoth machines, huge halls, conveyor belts, mining cars, and pipelines stand for an eventful and emotive chapter of industrial history. The Zollverein Coal Mine Industrial Complex in Essen (once Europe’s biggest mining city) used to be the world’s biggest coal mine. Its operation ceased in 1986. On the site at which 8,000 miners used to extract, process, and ultimately refine into coke up to 12,000 metric tons (13,200 short tons) of coal per day visitors today get to experience art, cultural life, and sports. The site even features a 12- by 5-meter (39- by 16-foot) swimming pool created by two maritime containers that have been welded together. In addition, 60 start-up companies have set up their businesses there. Visitors can of course literally delve into the miners’ world of work as well. Guided tours of Shaft XII, drilled down to as much as 1,000 meters (3,300 feet) below the surface, take them on a journey deep into the underground world.
Mothers of mass manufacturing
Even though, ultimately, Henry Ford only adapted existing manufacturing techniques he’s regarded as the “father of the assembly line.” His idea to start using them in 1913 to assemble his Model T had its origins in the world’s biggest meat factory, the Union Stock Yards in Chicago, where pigs and cattle hung on rotating conveyor chains called disassembly lines. The process of mass manufacturing, though, kicked off much earlier: As far back as in the 15th century, ships on their way to completion would pass through individual stations along a largely roof-covered assembly line in the Venetian shipbuilding yard Arsenale Novissimo that visitors can still tour today. The process also involved the use of hydraulic cranes. In total, the historic shipbuilding site covers around six percent of the urban area of Venice. The arsenelotti as the shipyard workers were called, at times numbering up to 16,000, installed standardized components. That, too, increased the operation’s output while ensuring Venice’s rise to the level of an influential maritime power.
Looking down to a depth of 218 meters
Who’s got the guts to walk it? The Hongyagu glass-bottomed bridge, located some 300 kilometers (186 miles) southwest of the Chinese capital of Beijing, is the longest of its kind worldwide. Across a length of 488 meters (1,600 feet), it connects two steep cliffs in the Hongyagu Scenic Area in the county of Pingshan. Hung between sets of three steel cables are 1,077 glass panels, each four centimeters (1.6 inches) thick. To protect them against scratching, visitors are allowed to walk on them only by wearing special booties. Although the bridge has been designed for the weight of 2,000 people and its load bearing capacity amounts to as much as 3.5 times the Chinese national standard only a maximum of 500 people may enjoy the spectacular view of the valley at the same time. The stairs located at each of the two ascending ends of the bridge are covered with glass panels as well. Tension cables installed diagonally below the bridge absorb wind-induced vibrations but don’t fully prevent them. The structure is designed to withstand the heaviest winds in that region. However, in case of gales the bridge is closed to visitors.
A trailblazer of Alpine tourism
People that don’t feel like hiking in the mountains can ride a train to the top of Mount Rigi. Europe’s oldest rack railroad that was built in just two years and opened more than 150 years ago in 1871 takes visitors to that Swiss summit which is nearly 1,800 meters (5,905 feet) high. That’s where the development of tourism in Switzerland and in all of Europe saw the start of a literally steep evolutionary curve. The rack railroad is regarded as a pioneering feat of technology. It’s special because the rack system of railroad pioneer Niklaus Riggenbach is still one of the most widely used ones in Europe. It can handle slopes of up to 50 percent. Although rack railroads previously existed in the UK and the US, Riggenbach invented a system of his own: a rack like a narrow ladder located between the rails for the wheels. Installed under the locomotive and the rail cars is a large cogwheel that engages with the cogs of the “ladder staves.” The racks that Riggenbach’s engineers laid back in those days are still operating on the five-kilometer (3-mile) railroad. Whenever the cogs loosen, they’re simply repaired. Obviously, that’s not a problem even after more than 150 years.
A record bridge construction
For many viewers, it’s one thing above all else: a beautiful bridge. However, at the time of its official opening on May 24, 1883, the New York Brooklyn Bridge was celebrated primarily as a technical masterpiece. The Brooklyn Bridge was the world’s longest suspension bridge at the time of its completion. With a length of 1,834 meters (1,595 feet) it surpassed the lengths of all previously built bridges by more than 50 percent. The main span of the bridge across the East River measures 486,3 meters (1,596 feet). The Brooklyn Bridge connects the New York boroughs of Manhattan and Brooklyn and with 120,000 vehicles, 4,000 pedestrians, 3,100 cyclists per day is one of the most important lifelines of the metropolis. Up until the middle of the 19th century, the construction of the Brooklyn Bridge was deemed to be unfeasible due to tidal currents and heavy ship traffic. Only Johann August Röbling, a German immigrant engineer, managed to convince the city of New York and investors. However, he didn’t get to witness the bridge’s completion due to having sustained fatal injuries during an inspection of the construction project. 27 of some 6,000 workers involved in the project between 1870 and 1883 lost their lives in work accidents as well. 24,000 kilometers (15,000 miles) of wire were used to suspend the bridge from the 40-meter (131-foot) tall granite towers. Each of the four supporting cables were compressed to a thickness of 40 centimeters (16 inches) with hot wire wrapped around them. Röbling designed the cables for a load six times higher than required and made his masterpiece fit for the growing traffic volume. Originally, the Brooklyn Bridge encompassed four lanes per direction of travel and one railroad lane. Today, there are three lanes in the direction of Brooklyn, two in the direction of Manhattan, and one for cyclists in both directions. The level above them accommodates a wide walkway. An upgrade to the tune of 800 million dollars in the 2010s has made New York City’s old “bridge lady” fit for the next century.
A Ferris wheel for vessels
Ship lifts are some of the most spectacular mobility structures if for no other reasons than their dimensions and moved masses. Among the few that exist in the world at all is one that’s unique in terms of its design: the rotating boat lift in Falkirk, Scotland. Like a giant Ferris wheel this technical wonder raises boats by 24 meters (79 feet) to cross over from the Forth and Clyde Canal to the Union Canal. The boats park in two water-filled caissons the ends of which are supported on small wheels so that they’ll maintain their horizontal position during the rotation of the arms. The “ride” takes 10 minutes. Upon arrival at the top, the boat crews are in for another specialty: a ride through one of the few waterway tunnels on this planet.
