Happy Birthday! CN Tower turns 40

The CN Tower turns 40 today.

When it was officially opened to the public, the tower put Toronto on the map and was considered a construction project ahead of its time.

Built in 1976 by Canadian National Railways at a cost of $63-million, the CN Tower was the tallest free-standing structure in the world at just over 553 metres. It held that distinction until 2010 when the Burj Khalifa in Dubai claimed the honour at just over 829 metres. It remains the third tallest tower in the world and is still the tallest free-standing structure in the Western Hemisphere.

In 1995, the tower was declared one of the modern Seven Wonders of the World.

Pat Quinn, who was an engineering consultant on the project, says the original designs called for a three pillar structure. Designers then toook parts of the original drawing into consideration when coming up with the final look.

The tower was not intended to be the tallest in the world. It’s main purpose was to transmit radio signals over the city’s tall buildings.

Some other interesting birthday facts:

– the tower is struck on average 75-80 times a year by lightning
– the tower was built to withstand an earthquake as strong as 8.5 on the Richter scale
– the tower is able to endure winds of up to 418 km/h (260 mph)
– in 2008, glass panels were installed in one of the tower’s elevators, making it the world’s highest glass floored panelled elevator
– the 2,579 steps make it the world’s longest metal staircase
– the tower is fitted with 1,330 LED lights which are used for some amazing custom light displays