Calgary Tower

The Calgary Tower is a 190.8meter free standing observation tower in Downtown Calgary, Alberta, Canada. Originally called the Husky Tower, it was conceived as a joint venture between Marathon Realty Company Limited and Husky Oil as part of an urban renewal plan and to celebrate Canada's centennial of 1967. The tower was built at a cost of $3,500,000 and weighs approximately 10,900 tonnes, of which 60% is below ground. It opened to the public on June 30, 1968 as the tallest structure in Calgary, and the tallest in Canada outside of Toronto. It was renamed the Calgary Tower in 1971.The building was a founding member of the World Federation of Great Towers.HistoryPlanning and constructionWhen Marathon Realty and Husky Oil built their new head offices in Calgary, they proposed building the tower both to honour Canada's centennial year of 1967 and to encourage urban renewal and growth of the downtown core. The structure was designed by W.G. Milne & A. Dale and Associates, and was designed to withstand earthquakes and winds of up to 161km/h. Construction began on February 19, 1967, and completed in 15 months at a cost of C$3.5 million. The column of the tower was built from an unprecedented continual pour of concrete. Pouring began May 15, 1967 and was completed 24 days later at an average growth of 25ft per day, a rate that was praised by industry officials as an "amazing feat of technical and physical workmanship".