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Around the world, new ground-breaking buildings captivate our attention as they re-define skylines, push architectural boundaries, and bring us to new heights. Architects continue to surprise us, innovating incredible new structures that challenge what we thought was possible.

To commemorate the architectural achievements of the 20th century, the American Society of Civil Engineers created a list of the seven wonders of the modern world. It includes – among other iconic winners – the Chanel Tunnel, the Panama Canal, the Golden Gate Bridge, and Canada’s own CN Tower.

While the CN Tower is no longer the tallest standing structure in the world (a title it held for an impressive 34 years), it remains an architectural marvel that inspires young engineers and architects everywhere. Every year, the CN Tower attracts over two million tourists with its incredible views, adrenaline-pumping Edge Walk, and an award-winning restaurant.

Working toward your architectural CAD Technician diploma? Read on to discover the story behind Canada’s most famous structure, and how it went from blueprint to record-breaking building in just a few short years.

Architects Identify the Need for a Toronto Tower

Students currently pursuing architectural technician training might find it hard to imagine Toronto’s skyline as anything but a skyscraper paradise -but it used to look very different before the 1960s. Low buildings were the norm until a huge construction boom took hold and taller structures began to erupt all over town. That dramatic change leads to a problem: radio and television signals were blocked by the impressive new buildings, and reception in the city was terrible.

An antenna big enough to reach above the new 1960s office towers needed to be built, and so a team of world-class architects and accompanying technicians was hired for the job.

The Plans for the CN Tower get Drawn up by Expert Architects

Originally, the design for the CN Tower involved a set of three independent pillars linked together by structural bridges at different heights. But, eventually, that design was revised. The team realized that they could create the world’s tallest structure by developing the hexagonal core designs that became the CN Tower.

Construction on the CN Tower Begins

Construction of the CN Tower started on February 6, 1973. The project was one of the most ambitious of its time and involved 40 months of 24-hour work, five days a week by 1, 537 employees.

After the solid foundation was built, workers used a massive mold to pour the concrete that would eventually become the iconic tower. Workers moved the adjustable mold up the tower with a ring of climbing jacks, and they gradually tightened the mold to give the tower its distinct tapered form.

A Close Call With the Antenna

To install the antenna of the CN Tower, the team commissioned the use of a former military helicopter, nicknamed Olga, to speed up construction time. The whole process was so impressive, it attracted curious tourists who wanted to watch the historic completion of the project.

During Olga’s first trip, however, there was a close call. Olga was dismantling part of the giant crane (used to build the tower) when the crane jerked to the side and effectively trapped the helicopter in the air. With only 50 minutes of fuel and the crane operator trapped 1500 feet in the air, it was a scary situation for everyone involved.

Fortunately, workers were able to burn the twisted crane bolts and Olga was able to land safely with just 14 minutes of fuel left.

After the incident, the rest of the antenna was mounted without a hitch and the CN Tower opened up to the public for the first time on June 26, 1976.

Are you interested in taking Architectural CAD Technician courses and helping to design the next iconic Canadian structure?

Visit Digital School for information about training programs or to speak with an advisor.