Visitors take the elevator up the top floor’s observatory deck to see the breathtaking city panorama. Families and couples dine or drink champagne by the window glistening with city lights. It is the celebratory scene of US National Skyscraper Day on September 3.

This rather glamorous day commemorates the birthday of an American architect, Louis H. Sullivan also known as “father of skyscrapers” who built one of the earliest. Since then, the onset of skyscraper construction has brought about the advanced construction technology around major cities of the world.

As skyscrapers are typically approximately 40 floors (492 ft, 150 m) or taller, its construction involves impeccable framework and state-of-the-art technology for upmost safety— to support its weight and protect its habitants from natural disasters. To achieve such a feat calls for steel, the sole material relied for its unique high-strength-to-weight ratio.

Empire State Building, Landmark of the City that Never Sleeps

Originated from “Empire State”, the nickname of New York, this sparkly landmark featured in the silver screen to popular songs is the prestigious international icon of New York City. A reason why we are probably most familiar with this particular skyscraper. Located at the heart of Manhattan, the west side of Fifth Avenue, the multi-colored tower lights of the Empire State Building take the lead in decorating the city’s night skyline. Originally built as a symbol of hope during the nation struggling through the Great Depression, this famed landmark has been recorded as the tallest building in the world for 40 years in between 1931 to 1971 with its magnificent 102-story status and height reaching up to 1,454 feet (443.2 m) including its antenna.

All the while it had exceeded the height of the tallest skyscraper in the vicinity, the Chrysler Building, by as much as 204 feet. It took a tremendous amount of manpower of 3,000 workers to complete the construction in record time—as short as 13 months. The Empire State Building set the record as the tallest skyscraper in the world, a title retained until the completion of the World Trade Center in 1972.

Visitors to the 360-degree open-air observation deck on 86th and 102nd floor observatory attracts around 4 million visitors where expansive sunrise and night view of the entire city and beyond is visible, overlooking the Central Park, Hudson River, and Statue of Liberty.

Designed to withstand the building’s heavy gravitational pull and strong winds, the structural frame of the building took 57,000 tons of steel columns and beams that formed a 3-D grid throughout.

Dubai’s Burj Khalifa, the Mega Tower Overlooking the Earth

Located in the exuberant city of Dubai, this thin, needle-shaped skyscraper is gaining more and more prestige each year as millions of visitors marvel at its glamorous status of 829.8 meters (2,722 feet). This $1.5 billion-worth super scraper is currently the tallest architecture in the world since its construction in 2009. Taking five years to complete, more than 12,000 workers took part in the process for what is twice the height of Empire State Building and three times that of the Eiffel Tower in Paris.

This superstructure taking center stage in the scenes of “Mission Impossible: Ghost Protocol”(2011) where Tom Cruise pulls an edgy stunt scene moving about the walls of the building with suction gloves, gaining further worldwide stardom.

The city’s breathtaking skyline is observed  from “At the Top” deck on the 124th floor where the neighboring country, Iran’s shores can be seen during days of high visibility. In the making of this magnificent structure, 31,400 metric tons of steel rebar was used.

Lotte World Tower, Guaranteed Security among the Clouds

POSCO provided 41,000 ton-worth of high-strength steel for the construction of Lotte World Tower(Source: Tourmate)

Soaring 555 meters into the clouds, Lotte World Tower situated in Jamsil, Seoul, is the fifth tallest skyscraper built incorporating the newest cutting-edge technology. It is the home to world’s highest glass-floored observation deck creating a thrilling sensation of vertigo on the 117th to 118th floor. The observation deck reveals Seoul’s mountainous landscape afar during the day.

Leading edge construction technology from around the world was integrated into the process, and POSCO’s exclusive technology played a considerable part in the project. Thick plates (usually over 100 mm) applied in the domestic market was no more than 80 mm. However, to construct the highest building in the domestic scene, POSCO supplied 41,000 ton-worth of 120 mm thick plates and HSA800 high-strength steel. HSA800 is POSCO’s world premium product of which is highly suitable as the construction material for high-rise buildings. Even a 1mm² amount of HSA800 could support a human being weighing 80 kg (176 lb) without trouble.

Shanghai Tower, the World’s Greenest Skyscraper

Shanghai Building is spotlighted as a sustainable mega-tall tower(Source: Asiantowers)

China’s tallest, and the second tallest in the world, the Shanghai Tower is one of the recent high-rise construction recognized for its efforts in sustainable architecture. Towering 632 meters high, this China’s newest architectural invention prides on the world’s fastest elevators, highest hotel, and restaurants, as well as the tallest observation deck.

By reducing the amount of construction material needed by 25 percent, it saved approximately $58 million in construction costs. It collects rainwater and reduces wastewater for energy conservation while combining the cooling and heating power system that cuts tons from carbon footprint. Furthermore, the engineers installed 200 wind turbines at the top of the power which generates about 10 percent of the building’s electricity.

Quintessential Steel in High-rise Buildings

Use of steel delivers a range of advantages aside from stability. High-tech steel used for construction enables thinner walls making for more spacious interiors and more windows. The most crucial element is the safety aspect which steel delivers. Natural disasters pose a great threat to tall buildings from typhoons to fire hazards. As the quality of steel high-strength steel used in the construction of mega buildings is high, the resilience and ductility provide a significant advantage.

POSCO’s exclusive technology, HAS high-strength steel is an example of a material that is resistant to earthquakes. It is 1.7 times stronger than regular steel while 30 percent lighter in weight. A perfect high-strength steel that absorbs strong vibration.

In Japan, the country often hit by earthquakes, high strength steel is highly preferable for good welding and economic value. Up to 880 N/mm² in yield strength (tensile strength 1,000 N/mm²) is highly preferred.

The tense competition for reaching new heights in mega-tall buildings are still underway. Saudi Arabia’s Jeddah Tower will soon become the tallest in ranking, setting aside Burj Khalifa. Its expected height reaches above 1,000 meters, and Dubai’s Creek Tower is expected to be completed in 2021 as an observation tower rising up at 1,300 meters. With the advent of Jeddah Tower towering above 1 km, an even newer era of skyscrapers will begin where steel frames will play an even more significant part of the future’s architecture—raising efficiency in limited city spaces while creating installation artwork befitting in the creation of the Megacity.

Having discovered the architectural wonders of the world that have reached new heights through the application of steel, a tour to any of the tall buildings may now hold new meaning. Cheers to the pinnacle of human design.

The U.S. is the birthplace of many iconic figures, movies, and buildings. The Statue of Liberty is one such work of art which stands as a symbol of freedom and independence. The Empire State building is another architectural icon in the center of New York, a city which in and of itself represents the U.S. Although these monuments appear majestic on the exterior, it is their interior composition that has kept them standing tall all these years. These and other international iconic structures embody the limitless ways steel builds culture around the globe.

The Statue of Liberty

A Gift from the French

An early sketch of the Statue of Liberty (Image courtesy of Copper Development Association Inc.)

More than a hundred years ago, the French sent a giant gift to celebrate America’s independence and to honor their friendship. The Statue of Liberty was first assembled in France, taken apart, shipped to the U.S. and then erected once more. It still stands tall, but even stronger today thanks to some important improvements made along the way.

As the Leaning Tower of Pisa is to Italy and the Eiffel Tower is to France, the Statue of Liberty embodies and represents America’s values of freedom and independence. Although Lady Liberty looks as smooth and stunning as her first debut, her journey was nothing short of rocky.

The statue was assembled in the U.S. in 1886. The iron and copper figure stood the test of time for almost 100 years. However, from 1982 to 1986, the statue underwent major reparations to so that Lady Liberty could make it to her centennial anniversary in 1986. It was a costly effort, and interestingly, marked one of the earliest joint efforts between the private and public sectors to fund a public project.  

What was wrong with Lady Liberty?

In short, the Statue of Liberty can be broken down into three main parts: the copper exterior (a sheet of copper that covers the entire statue), the internal skeleton or pylon made of puddled iron, and the Armature (a frame that connects the copper exterior to the internal skeleton).

The armature is made up of iron bars, 1300 of them, weighing 20 pounds each. Due to concerns about corrosion, layers of protective materials were applied to the bars, such as coal tar, aluminum, and lead. The coating itself weathered over the years and began to trap moisture. Thus, the iron started to rust.

Engineers decided to replace the entire armature, but with what?

Four prospective materials underwent extensive testing:

1. Aluminum bronze
2. Cupro-nickel
3. Ferralium
4. Stainless steel

The obvious choice was stainless steel as it would not rust, but also gift builders with its elasticity, light-weight, strength, and ductility.

Ten years after the repairs, in 1996, inspectors deemed the armature corrosion-resistant and it has remained so ever since. It would have been wiser and less costly to start with steel in the first place, as the engineers of the Empire State Building did, but it seems even steel could use… even more steel.

A Steel on Steel Testament

The Empire State Building Stands tall in the middle of New York City

In the Big Apple, The 86-year-old Empire State Building also recently underwent enhancements. Engineers added 39 tons of steel plates onto the building’s existing steel mast (the pointy part at the top, also known as the tower) to improve its carrying capacity.  

The planning for this project alone took over two years. Steelworkers, engineers, and builders had to take into account the bustling city below. High winds were another factor to consider. In the end, engineers came up with a cocoon-like encasing to be placed around the tower at the top of the building during construction to keep falling pieces in and strong winds out.  

Once set inside the cocoon, workers began wielding 39 tons worth of steel bars and plates onto the tower. The process was tedious as steel parts could only be transported into the cocoon in small pieces.  

In the end, the sturdier mast with a greater carrying capacity was worth the struggle.

The Empire State Building was built in 1931 and was the tallest building in the world at the time. Due to its unique design, the American Society of Civil Engineers named it one of the Seven Wonders of the Modern World. It is also a significant part of American culture, as the Empire State Building has been featured in more than 90 movies, including “King Kong” in 1933.  

Every year, the Empire State Building generates more than $100 million in revenue. About 20% of the revenue comes from the antennas attached to the 200-ft-tall steel broadcast tower. The remaining 80% is generated by the flocks of tourists that visit from all over the world, confirming the Empire State Building as an international landmark.  

However, it is not the only building receiving international attention and recognition.

The Leaning Tower of Abu Dhabi

The Capital Gate Building in Abu Dhabi, UAE leans westward in the Abu Dhabi National Exhibition Centre complex (Image courtesy of Abu Dhabi National Exhibition Center)

Abu Dhabi is another country where steel lays the foundation for iconic buildings. The Capital Gate Building may not have a long history, but it is an architectural wonder. It is often compared to Italy’s Leaning Tower of Pisa, but it has four times leaner The Capital Gate leans to the west a whopping 18 degrees.

How is this possible?

Engineers used a technique called pre-cambered core. Basically, they offset the core to counter the gravitational force created by the leaning mass of the building. The core or base of the building is a 7-foot mass of steel mesh and concrete locked down to almost 500 piles, which are drilled 100 feet into the ground. The external skeleton called a diagrid is also made of steel. These features, as well as some extensive math equations, allow the building to stand tall, at an angle.

The landmark leans in the center of the Abu Dhabi National Exhibition Centre complex and the Capital Centre master development. It captured international attention when The Guinness Book of World Records confirmed the Capital Gate Building as the “World’s furthest leaning man-made tower” in 2010.  

The list of iconic steel structures is endless…

Although the ones we discussed are just three iconic structures, it’s easy to see why steel makes up so many other buildings, statues, and memorials all over the world.  In the U.S. alone, iconic structures such as the Brooklyn Bridge, the Gateway Arch in St. Louis and the Willis (Formerly Sears) Tower are all made of steel.

Steel is cheaper, more sustainable and more durable than other materials such as iron and wood.

In addition, emerging technology will only further enhance the compatibility of steel for architecture and construction. One promising area of innovation is 3D printing for buildings.

The Mesh Mould 3D Printer developing a steel frame (Image courtesy of Gramazio Kohler Research)

Printing Steel in 3D

The typical concrete construction process consists of:

1. Setting up a steel/metal frame (rods) for the building
2. Pouring concrete over the rods
3. Formwork- using a wooden “shell” to hold the concrete in place as it dries

The problem with this process is the formwork. Because custom-made formwork is extremely expensive and non-reusable, builders opt for standardized, block-shaped formwork. This limits design creativity on top of the economic and environmental inconvenience.

Mesh Mould is a digital 3D printer in the works by researchers at the ETH Zürich research institute. The printer would produce steel frameworks that are both fine and dense, so that poured concrete would not seep out before it solidifies. The developers of Mesh Mould also created a special concrete mix to accompany the steel frames. Mesh Mould would eliminate formwork completely. Not only will this make the whole construction process more sustainable, it will lower material expenses and also save time. Others have taken notice as well. Mesh Mould received the 2016 Swiss Technology Award.

Statues, building, and monuments can be made of numerous different materials. However, when exploring iconic buildings and monuments that have stood the test of time and breached scientific barriers, steel proves to be the perfect fit.

The images that cross your mind may seem apocalyptic, or even impossible to fathom. There is barely a part of our lives today that is not influenced by the metal, and it is not an exaggeration to say that steel is perhaps the most significant component of the modern world. Without it, civilization as we know it would cease to exist. Let’s take a look at a few ways the world would be a different place without steel.

Skylines would be incredibly boring.

Structures such as skyscrapers and towers would be inconceivable without steel supports and cables. Therefore, buildings would be low-rise at their tallest, making densely populated cities devastatingly uncomfortable. It’s hard to imagine a world without the likes of the Burj Khalifa, the Eiffel Tower or the Empire State Building, all of which utilize steel as a main construction component.

We’d have very few options for dinner.

The food we eat today has been refined in factories with steel tools, processed with steel equipment, baked in steel ovens and preserved in steel cans. It is delivered to us via steel trains on steel rails, or by steel trucks over steel-reinforced roads. As such, in a world without steel, our food sources would be limited to what could be cultivated locally and the possibility of faminewould be persistent.

Getting in touch would take for-ev-er.

(Image source: http://bit.ly/1dgLFuc)

Without steel to manufacture telephones, computers or even mail trucks, we would be stuck relying on less than efficient carrier pigeons (which were actually a thing a few thousandyears ago) or the pony express. So much for instant connection.

Reading material would be extremely limited.

(Image source: http://bit.ly/1tNFW6q)

Newspapers, magazines and books we read today are mostly printed on a steel press. Even the paper is made from wood which is cut with steel implements and processed in steel machines. Mind you, there wouldn’t be any steel-plated pens, either, so quills would be used to write and copy the material. Of course, there might be bronze movable type printing, but it would still take a very long time and amount of patience to carry out.

Disease would run rampant.

Stainless steel has contributed greatly to improved sanitation in hospitals, restaurants and other public environments, and has helped to save the lives of millions. Easy to clean, it is more hygienic, impervious to corrosion and scratch-resistant, and is capable of standing up to harsh sterilizers, heat and heavy use, preventing deadly bacteria from surviving on its surface. Without it, the constant threat of diseases such as Ebola and measles would be very real.

Unemployment would rise and the economy would crumble.

Crude steel production reached 1.66 billion tons worldwide in 2014 which only says one thing about our world… it’s growing. It’s estimated that more than 95 countries are producing steel today, with more than two million employees worldwide, and a further two million contractors and four million people in supporting fields. Without this vital industry, the world economy would suffer and many people would be without jobs.

A glimpse into the world of steel

Fortunately, we do live in a modern world where steel does exist and its importance is clear. Yet few people tend to notice it, or understand how it works. Which is why TenarisUniversity, in conjunction with the World Steel Association’s steeluniversity, has launched the massive open online course (MOOC), “Introduction to Steel.”

This lively online learning program will feature the basics of steel melting, steel’s historical and cultural context, its relationship with society and the sustainability of a world supported by steel by utilizing everyday examples, demonstrations and film footage of steel making. Additionally, it will encourage community interactions between students and the professor.

“We believe in the highest standards of education to develop people all around the world,” Rolando Lange, Director of TenarisUniversity noted. “With this MOOC, we hope students will get passionate about steel as a material and learn about the critical role it plays in our society.”

Comprised of a four-hour framework, the course is open to all free of charge. It starts on June 2 and will run for two weeks. Registration is now open. Click here to enroll in the class, or for more information.