The history of civilization is replete with examples of humanity improving the world in which it lives. Through ingenuity, imagination, and hard work, humanity has spanned rivers, built roads, erected cities, and created the infrastructure to connect them. Some projects took centuries to complete; others were finished with alacrity, driven by immediate needs. Many were treated with derision by contemporaries who considered the vision of their proponents’ to be delusional. Some — the Panama Canal being one example of many — were completed only after a spectacular and expensive failure during earlier attempts. Still others were spurred by the competition between nations and empires.
Spectacular feats of engineering preceded the term engineer. The master builders and visionaries evolved over the centuries from mathematicians (spontaneously, it would seem) across the globe. The Great Wall in China, the pyramids of the Maya and Aztec cultures, the cities of the ancient world all were accomplished by engineering, though the builders and designers were unaware that they were engineers. Over the centuries, engineering accomplishments were directed at the worship of gods and heroes, the improvement of societal life, and to simply celebrate the spirit of humanity. Here are 10 of the greatest engineering achievements in history.
10. The Roman water distribution system
Three centuries before the beginning of the Common Era the Roman Republic, later the Empire, distributed water throughout its dominions using a system of canals, pipes, reservoirs, standing tanks, and aqueducts. Entirely through the use of gravity the Romans distributed fresh water to cities and towns, as well as to mines and farms. Some of the aqueducts still stand, architectural marvels built by laborers under the supervision of surveyors and master builders. By the end of the third century the city of Rome was serviced by eleven separate water conduits distributing water throughout the city, and in the case of the wealthier citizens directly into their homes. Poorer residents resorted to public wells and baths.
The empire was serviced with water systems as well, operated by both local governments and the state. Natural springs were the preferred sources of water. Easements were established by law on either side of the conduit’s pathway. The waterways were liberally supplied with inspection points – which would today be called manholes – and the water was routinely inspected for purity. Lead pipes were used in some sections, though the use of ceramic piping was preferred, and sections of the aqueducts which were of concrete were lined with brick, to prevent erosion and to help filter the water. The system was so well designed and built that there are sections still in use for the distribution of fresh water nearly 20 centuries after they were built.
9. The Cathedral of Hagia Sophia
Built as a Christian church and later converted to an Islamic mosque, the Cathedral of Hagia Sophia is today a museum, and an iconic image of Turkey. Originally constructed in the sixth century it has survived rioting, looting by conquerors, earthquakes, fires, and the ravages of time. Built chiefly of masonry, it is easily recognized by its corner minarets and its massive dome. Built and rebuilt many times over the years, it remains a symbol of Byzantine architecture, and for over 1,000 years Hagia Sophia was the largest cathedral in the world. Its design was revolutionary in its day.
The huge dome is set upon a square base, supported by four triangle shaped pendentives in the square’s corners. The pendentives carry the weight of the dome and direct it downwards, rather than outwards as the shape of the dome would otherwise dictate. Though the dome collapsed on more than one occasion, and was modified during rebuilding to include ribs which help distribute its weight to the supporting walls, each rebuilding strengthened it and improved the overall structure of the building. Hagia Sophia is a museum of both the Christian and Islamic faiths, as well as the Byzantine Empire and the Crusades. It remains one of the largest masonry buildings in the world in the 21st century.
8. The Leshan Buddha
Carved from a single stone and completed in the early ninth century, the Great Buddha of Leshan stands over 230 feet tall, with breadth across the shoulders of 92 feet. It is the tallest statue of Buddha to be found in the world, carved from the sandstone of a cliff overlooking the junction of the Min and Dadu Rivers in Sichuan. Ordinarily, sandstone would be easily eroded by the rainwater which has fallen on the statue over the centuries. That it hasn’t is a tribute to the ingenious engineering which controls the flow of water through and behind the statue, which has served to protect it since its completion circa 803 CE.
The Leshan Buddha includes over 1,000 coiled hair buns, of stone, which are placed on the statue’s head. They were designed to collect rainwater, and to route it to a system of drains and drainpipes which allow the water to flow through the statue’s head and arms, draining out the back, behind the stone clothes and away from the statue, protecting it from the effects of erosion. The system was installed as part of the original carving. Originally protected by a wooden shelter which was destroyed by the Mongols, the statue has stood exposed to the elements for seven centuries, with its drainage system protecting it from erosion. Today the greatest threat to the statue is the heavily polluted air of the region, a factor its designers could not have anticipated.
7. The Erie Canal
Between the Hudson River and Lake Erie land elevation increases by about 600 feet. Canal locks of the day (1800) could raise or lower boats about 12 feet, which meant that at least 50 locks would be required to build a canal which linked the Hudson with the Great Lakes. President Thomas Jefferson called the project “…little short of madness.” New York’s governor, Dewitt Clinton, disagreed and supported the project, which led to its detractors calling the canal “Dewitt’s Ditch” and other, less mild pejoratives. Clinton pursued the project fervently, overseeing the creation of a 360 mile long waterway across upstate New York, which linked the upper Midwest to New York City. The cities of Buffalo, New York, and Cleveland, Ohio, thrived once the canal was completed, in 1825.
The engineering demands of the canal included the removal of earth using animal power, water power (using aqueducts to redirect water flow), and gunpowder to blast through limestone. None of the canal’s planners and builders were professional engineers, instead they were mathematics instructors, judges, and amateur surveyors who learned as they went. Labor was provided by increased immigration, mostly from Ireland and the German provinces. When it was completed in 1825 the canal was considered an engineering masterpiece, one of the longest canals in the world. The Erie Canal’s heyday was relatively short, due to the development of the railroads, but it led to the growth of the port of New York, and spurred the building of competing canals in other Eastern states.
6. The Brooklyn Bridge
The Brooklyn Bridge was originally envisioned by John Roebling, who had built suspension bridges of shorter spans across the Ohio River and at other locations. The project in Brooklyn and Manhattan led to an accident which cost Roebling his life, and the engineering challenges passed to his son, Washington Roebling. Washington was stricken with the bends early in the construction, and was forced to supervise the project from his Manhattan apartment. The engineering challenges were difficult; wooden caissons were sunk to the bottom of the East River, with men inside them to excavate the river bottom until the caissons reached bedrock. In the case of the east tower supporting the bridge, they never did. The tower rests on sand to this day.
It took 14 years to complete the project, from 1869 -1883. Often described as a suspension bridge, the structure is in reality a hybrid suspension/cable stayed bridge, with the load of the span transferred by wire cables to the towers, and thence to the bedrock on the Brooklyn side, and the sand over the bedrock on the Manhattan side. In the 21st century it carries six lanes of traffic as well as bicycles and pedestrians, though it no longer accommodates rail traffic, nor commercial vehicles. It was considered the engineering masterpiece of the world at the time of its completion, spanning nearly six thousand feet, and linking the formerly separate cities of Brooklyn and New York.
5. The Eiffel Tower
Gustave Eiffel built the iconic symbol of Paris – indeed of all of France – to serve as the gateway to the 1889 World’s Fair. Contrary to popular belief, Eiffel did not design the tower, instead purchasing the patent rights to the design from engineers within his employ. He then signed a contract for the construction of the tower acting as himself, rather than as his company, and later set up another company to handle the management of the tower and the income derived from it. The design of the tower was controversial from the outset, with artists and engineers complaining of its lack of esthetic value. It was said that French writer Guy de Maupassant ate at the restaurant in the tower after its completion because it was the only place in Paris from which the tower could not be seen.
The ironwork was delivered to the site with holes for connecting bolts predrilled, and as they were installed the tower was brought into proper alignment through the use of hydraulic jacks installed near the four feet of the structure. Creeper cranes climbed the legs of the tower to erect each succeeding level. The tower was declared complete in March 1889, at the time the tallest manmade structure in the world. It reached the height of 1,063 feet and remains the tallest structure in Paris. The tower was to have been dismantled in 1909, under the terms of the original contract, but its usefulness as a radio transmitter gained it a longer lease on life. By the end of the twentieth century the idea of dismantling the tower was unthinkable.
4. The Panama Canal
The 51-mile long cut across the Isthmus of Panama was a dream for many decades prior to the French beginning its construction in 1881. During the building of America’s Transcontinental Railroad, equipment for use in the Sierras was shipped from the east coast of the United States to Panama, transferred across the Isthmus, and then shipped to California. Engineers for years studied the building of a canal before the French attempted to complete one, but the engineering difficulties combined with the climate and politics to thwart their efforts after more than two decades. The United States stepped in where the French failed, and completed the canal in 1914, after another ten years of work.
The canal is actually two canals, connected on either end with an artificial lake, Lake Gatun, located 85 feet above sea level. Locks on the two canals raise or lower ships to or from the level of the lake, allowing them to traverse from Atlantic to Pacific, or vice versa. The canal allows ships to transfer from one ocean to the other in just under twelve hours. It was the engineering decision to abandon the sea level canal design favored by the French and instead create Lake Gatun through the building of Gatun Dam (then the largest dam in the world) and install locks to raise and lower ships which allowed the Americans to succeed in completing the dam, which changed shipping lanes and inter-ocean traffic forever.
3. The Channel Tunnel
For centuries the British Isles remained unconnected to the European continent, a situation which many Britons favored as critical to their national security. Numerous proposals for a tunnel beneath the channel were put forth, but opposition within England and France prevented any serious efforts. Attempts to build tunnels for automobile traffic were started and stopped in the mid-to-late 20th century. Finally, in the late 1980s, after the usual political and professional maneuvering among governments, businesses, and financiers, work on the tunnels for high speed rail trains got underway, already bearing the nickname by which it is best known today, the Chunnel.
The tunnel was built from both sides, using massive tunnel boring machines – TBMS – to approach each other. The machines bore through what is mostly chalk, though the varying geology of the French shore created some difficulties. Both the French and English used the removed spoil for land reclamation projects. The tunnels were lined with both cast iron and reinforced concrete. When completed, the tunnel provided electrical power to the trains running through it via overhead lines. The tunnel opened in 1994, and today allows for a trip from London to Paris in just over two hours. The tunnel also allows for freight traffic delivering goods manufactured throughout Europe to be imported to Britain, and British goods to find markets on the continent.
2. Burj Khalifa
The world’s tallest structure as of 2019, Burj Khalifa is a mixed use skyscraper in Dubai, which was completed in 2009. The building was designed by the same Chicago firm which designed the Willis Tower (formerly the Sears Tower) in that city, and uses the same engineering principle of bundled tubes at its core to support the building’s weight. The tubular design allowed for substantially less steel to be used in construction, with most of the building being reinforced concrete. Its spire alone, which is mostly decorative, would qualify it as the 11th tallest structure in Europe were it erected on the continent.
The building has an outdoor swimming pool located on the 76th floor, with another on the 43rd floor. A 300 room hotel is located within the building, as well as corporate offices and private apartments. For those of a hardy constitution, 2,909 steps connect the ground floor with the 160th. The observation deck is located on the 124th floor. The surrounding park, known as Burj Khalifa Park, is landscaped with desert plants which are kept hydrated using water collected by the building’s cooling system, which itself relies on the cooler air of the upper portion of the building to decrease the temperatures of the lower portion of the structure.
1. The Apollo Space Program
It remains one of the signature engineering achievements in the history of the human race. No other program has delivered human beings to an environment other than their home planet and returned them safely to earth. Americans not only walked on the surface of the moon, they drove on it, using a battery driven vehicle designed for the purpose, capable of carrying two astronauts and greatly increasing the area which the lunar explorers could cover. It was carried to the moon within the Lunar Excursion Module (LEM) and used for the final three moon missions in the early 1970s. In 2003, the National Academy of Engineers called the program the “…greatest engineering team effort in American history.”
The Apollo program led to significant advances in the development of integrated circuitry, contributed to the growing cause of environmentalism, and over 20% of the world’s population watched on television when astronaut Neil Armstrong left the first human footprints on the lunar surface. NASA claimed spin-offs from the space program in the areas of freeze-dried foods, emergency reflective blankets, hand-held portable vacuum cleaners, and more than 2,000 other areas. LASIK surgery is a direct descendant of the technology developed to dock with vehicles in space, first performed as part of the Gemini program, in which astronauts learned the techniques required of Apollo.