Seven Wonders of the Modern World as named by ASCE

As a tribute to the greatest civil engineering achievements of the 20th century, the American Society of Civil Engineers (ASCE) has chosen the Seven Wonders of the Modern World.

The international wonders demonstrate modern society's ability to achieve unachievable feats, reach unreachable heights, and scorn the notion "it can't be done."

ASCE honored the following civil engineering marvels:

• Channel Tunnel (England & France)

• CN Tower (Toronto)

• Empire State Building (New York)

• Golden Gate Bridge (San Francisco)

• Itaipu Dam (Brazil/Paraguay)

• Netherlands North Sea Protection Works (Netherlands)

• Panama Canal (Panama)

The Society sought nominations from civil engineering societies and distinguished engineering experts from around the world. From their consensus emerged the Seven Wonders, which were judged on factors such as pioneering of design and construction, contributions to humanity, and engineering challenges that were overcome.

The list evokes the storied seven wonders of the ancient world, which first illustrated humanity's fascination with engineering works that seemingly defied the limits of nature. While only a few of the original wonders remain, the modern wonders represent civil engineering's legacy to the 20th century.

The Seven Wonders of the Ancient World:

• The Pyramids of Egypt

• Hanging Gardens of Babylon

• Statue of Zeus at Olympia

• Colossus of Rhodes

• Temple of Artemis at Ephesus

• Mausoleum of Helicarnassus

• Pharos (Lighthouse) of Alexandria

"The original wonders were amazing sites to behold, but today's modern wonders are more than simply awe inspiring. They are functional, operational masterpieces that have revolutionized civil engineering and benefited humanity. The Seven Wonders of the Modern World are a tribute to universal human desire to triumph over the impossible," added Charles A. Parthum, ASCE 1996 President.

A glimpse at the future...

To be considered a modern wonder, projects must have been completed and fully operational, thus several of the world's largest undertakings were not eligible for consideration. With Asia leading the way, the seven wonders of the 21st Century could be quite different. In another 50 years, the list of civil engineering wonders may include:

• Akashi-Kaikyo Bridge -- Links the city of Kobe with Awaji Island in Osaka Bay. With a main span of 6528 feet, Japan boasts the world's longest suspension span.

• Kansai International Airport -- This Japanese airport lies on a vast artificial island planted a full 3 miles from shore.

• Petronas Twin Towers -- One of the world's tallest building recently has graced Kuala Lumpur at a height of 1476-ft.

Itaipu Dam

Five miles wide and requiring enough concrete to build five Hoover Dams, the Itaipu Dam spans the Parana River at the Brazil/Paraguay border. During its construction, workers shifted the course of the seventh largest river in the world by removing 50 million tons of earth and rock to dig a 1.3-mile bypass. The main dam, as high as a 65-story building, is composed of hollow concrete segments, while the flanking wings are earth and rock fill. Enough iron and steel was used at Itaipu to build 300 Eiffel Towers. Another marvel of Itaipu is its powerhouse -- half a mile long, half underwater and containing 18 hydroelectric generators each 53 ft. across. Some 160 tons of water per second pour onto each turbine, generating 12,600 mega watts --enough to power most of California. Itaipu currently supplies 28 percent of all the electric energy in Brazil's south, southeast and central-west regions, and 72 percent of Paraguay's total energy consumption.

Channel Tunnel

The 31-mile Channel Tunnel (Chunnel) fulfilled a centuries-old dream by linking Britain and the rest of Europe. It's more than a tunnel -- it rolls infrastructure and immense machinery into an underwater tunnel system of unprecedented ambition. Three concrete tubes each 5 ft. thick, plunge into the earth at Coquelles, France and burrow through the chalky basement of the English Channel. They reemerge at Folkstone, behind the white cliffs of Dover. Through two of the tubes rush the broadest trains ever built -- double decker behemoths 14 ft. across -- traveling close to 100 mph. Passengers board not on foot, but in automobiles and buses. Maintenance and emergency vehicles ply the third tunnel, between the rail tubes. Meanwhile, machines are always at work, turning the Channel Tunnel into a living, intelligent structure. Huge pistons open and close ducts, relieving the pressure that builds ahead of the train's noses. Some 300miles of cold water piping run alongside the rail tracks to drain off the heat raised by air friction.

CN Tower

The world's tallest free-standing structure soars 1,815 ft. above the sidewalks of Toronto, three times the height of its better-known cousin, the Seattle Space Needle. The CN Tower, as heavy as 23,214 large elephants, was erected at an amazing rate of 18 ft. per day. During construction, concrete flowed from the bottom of the tower as it ascended, while aircraft-type bombsights kept the tower plumb as it went up. Today the tower is off by a mere 1.1 inch. Designed with the aid of a wind tunnel, the CN Tower can withstand 260-mph gusts. The SkyPod, a seven-story structure 1,100 ft. high, was built around the base of the tower and jacked into place as one unit. A pair of 10-ton counterweights are attached to the mast to keep the tower from swaying too much. A Sikorsky helicopter hoisted the crowning antenna, for which the tower was originally erected. FM radio signals are broadcast from the base of the antenna, while television signals are sent from the top. Presently, 16 of Toronto's media signals are transmitted from the tower.

The Panama Canal

The dream of Spanish conquistadors and the failed ambition of famed French canal builder Ferdinand de Lesseps, the Panama Canal is one of civil engineering's greatest triumphs. Under the direction of U.S. Col. George Washington Goethals, 42,000 workers dredged, blasted and excavated from Colon to Balboa. They moved enough earth and rubble to bury the island of Manhattan to a depth of 12 ft. -- or enough to open a 16-ft.-wide tunnel to the center of the Earth. The canal was finished on time and within budget. But after completion, a challenge remained: how to tame the flood waters of Chagres River, known to rise 25 ft. in a day during monsoon season? Solution: Civil engineers erected a dam that formed the world's then-largest man-made lake. Today the Canal operates much as it did in 1914. In each transit, 52 million gallons of fresh water is lost, but it is quickly replaced by Panama's heavy rainfall. The canal remains a testament to the combined skills of structural, geotechnical, hydraulic and sanitary engineers.

The Golden Gate Bridge

More than 60 years after its completion, the Golden Gate Bridge remains the world's tallest suspension bridge. Hanging from two 746-ft-high towers, its cables -- each a yard thick --are the biggest ever to support a bridge. In fact, the Golden Gate Bridge contains enough cable to encircle the earth three times. To leap across the mouth of an ocean harbor, something never before accomplished, civil engineers planted one pier in the open sea, 1,000 ft. from the shore. Construction crews braved biting cold, 70-mph gusts and dizzying heights to complete the bridge in only four years. The bridge combines engineering strength and beauty. It survived the 1989 Loma Prieta earthquake, and weather has shut it to traffic only three times in 60 years. Currently the span is undergoing a seismic retrofit to withstand a 90-second earthquake that measures 8.3on the Richter scale. Today, the Golden Gate Bridge remains one of the world's most revered, and photographed bridges.

Empire State Building

At 1,250 ft. the Empire State Building is the best-known skyscraper in the world, and was by far the tallest building in the world for more than 40 years. The building's most astonishing feat however, was the speed in which it rose into the New York City skyline. Construction was completed in only one year and 45 days, without requiring overtime. Ironworkers set a torrid pace, riveting the 58,000-ton frame together in 23 weeks. While just below them, masons finished the exterior in eight months, and plumbers laid 51 miles of pipe and electricians installed 17 million ft. of telephone wire. The building was so well-engineered that is was easily repaired after a bomber crashed into it in 1945. The precise choreography of the operation revolutionized the tall building construction industry. Although it has been surpassed as the world's tallest building, the Empire State Building remains the standard against which all other skyscrapers have been judged for the last 65 years.

North Sea Protection Works (Netherlands)

Unique in the world, this vast and complex system of dams, floodgates, storm surge barriers and other engineered works literally allows the Netherlands to exist. For centuries, the people of the Netherlands have repeatedly attempted to push back the sea -- only to watch merciless storm surges flood their efforts, since the nation sits below sea level and its land mass is still sinking. The North Sea Protection Works consists of two monumental steps the Dutch took to win their struggle to hold back the sea. Step One -- a 19-mile-long enclosure dam built between 1927 and 1932. The immense dike, 100 yards thick at the waterline, collars the neck of the estuary once known as the Zuiderzee. Step Two was the Delta Project to control the treacherous area where the mouths of the Meuse and Rhine Rivers break into a delta. The crowning touch was the Eastern Schelde Barrier, a two-mile barrier of tell gates slung between massive concrete piers. The gates fall only when storm-waters threaten. The North Sea Protection Works exemplifies humanity's ability to exist side-by-side with the forces of nature.

Copyright © 1996, 1997 ASCE. All rights reserved.

This website was originally developed by Charles Camp for CIVL 3121. This site is maintained by the Department of Civil Engineering at the University of Memphis. Your comments and questions are welcomed.