When construction of the CN Tower was complete in 1976 it became the world’s tallest free-standing structure and world’s tallest tower at the time. It held both records for 34 years until the completion of Burj Khalifa and Canton Tower in 2010.
It is now the 3rd tallest tower in the world and remains the tallest free-standing structure in the Western Hemisphere.
It was built by the state railways, the Canadian National Railway, known by the acronym CN, origin of the name of the tower.
The project’s architects were John Andrews, Roger Du Toit, and the Webb Zerafa Menkès Housden Partnership; the structural engineer was R.R. Nicolet.
Construction on the CN Tower began on February 6, 1973 and wrapped up about 40 months later in June 1976. In those 40 months, there were 1,537 workers working 24 hours a day, five days a week.
The CN Tower was built at an original cost of CA$63 million.
The CN Tower weighs 117,910 metric tonnes (130,000 tons) which is 35x the weight of the Eiffel Tower or 23,214 elephants.
The CN Tower consists of several substructures. The main portion of the tower is a hollow concrete hexagonal pillar containing the stairwells and power and plumbing connections.
On top of the main concrete portion of the Tower is a 102-meter (334.6 feet) tall metal broadcast antenna, carrying TV and radio signals.
The Tower’s six elevators are located in the three inverted angles created by the Tower’s hexagonal shape (two elevators per angle).
The Tower’s glass fronted elevators also feature glass floor panels and take only 58 seconds to get to the top.
The main deck level is seven storeys, some of which are open to the public.
The Glass Floor and Outdoor Observation Terrace are both located at an elevation of 342 meters (1,122 ft).
The Glass Floor is an indoor area from which you can see the 342 meters that fall under the glass plates forming the floor and the terrace outside the Tower.
Outdoor Observation Terrace, is a viewpoint whose only protection is a wire mesh.
At 346 meters is the Lookout Level, which is located in the Café Horizon and an observation deck inside.
The 360 Restaurant, a revolving restaurant that completes a full rotation once every 72 minutes, is at 351 meters (1,152 feet). In 2006, Guinness World Records dubbed it the world’s highest wine cellar.
On August 1, 2011, the CN Tower opened the EdgeWalk, an amusement in which thrill-seekers can walk on and around the roof of the main pod of the tower at 356 m eters (1,168.0 feet), which is directly above the 360 Restaurant. It is the world’s highest full-circle, hands-free walk.
Below the public areas on main deck — at 338 meters (1,108.9 ft) — is a large white donut-shaped radome containing the structure’s microwave receivers.
The highest observation deck, the SkyPod stands 447 meters (1,465 feet). On a clear day, visitors can see Niagara Falls from the SkyPod. The SkyPod was once the highest public observation deck in the world until it was surpassed by the Shanghai World Financial Center in 2008.
A metal staircase reaches the main deck level after 1,776 steps, and the SkyPod 100 meters (328 feet) above after 2,579 steps; it is the tallest metal staircase on Earth.
In June 2007, the tower was outfitted with 1,330 super-bright LED lights. The CN Tower’s funky LED illumination light system is energy-efficient, low-maintenance, and free of UV radiation. It can also be controlled and directed, meaning that the Tower’s colors regularly change; it goes green for Earth Day, turns blue for the Toronto Blue Jays’s home opener, and becomes red and pink for Mother’s Day.
The CN Tower dims unnecessary exterior lights during bird migration seasons to prevent bird injuries.
The CN Tower is struck by lightning approximately 75 times each year. There are copper grounding rods that run down the side of the tower into the ground.
The CN Tower is reportedly able to withstand an earthquake as strong as 8.5 on the Richter scale. It is also able to withstand winds up to 420 kilometers (260 miles per) hour.
The CN Tower is almost perfectly vertical. It is only off by 2.79 centimeters (1.1 inches).
The CN Tower is a signature icon of Toronto’s skyline, and a symbol of Canada.
In 1995, the CN Tower was declared one of the modern Seven Wonders of the World by the American Society of Civil Engineers.
It also belongs to the World Federation of Great Towers, where it holds second-place ranking.
The CN Tower attracts more than two million visitors each year.
Stuntman Dar Robinson jumped off of the CN Tower on two occasions in 1979 and 1980. The first was for a scene from the movie Highpoint, in which Robinson received $250,000 for the stunt. The second was for a personal documentary. Both stunts used a wire decelerator attached to his back.
In 2015, as part of the Pan Am Games, French BASE jumpers Fred Fugen and Vince Reffet surprised onlookers when they jumped from the top of the tower while film crews and a crowd looked on.