Really Tall Buildings

On this day in 1975, construction of the CN Tower in Toronto was completed. At the time, it was the tallest free-standing structure in the world, at 553.3 meters (1815 feet) tall. Since that time, a new standard has been established, and the Middle Eastern countries are acting like drunk Texans in trying to have the "biggest and best" buildings. The Burj Dubai (Dubai Tower), shown at right in a photo from about a year ago, is scheduled to be completed in 2009, is going to be well over 2000 feet tall, and have about 162 usable floors. It's already taller than the CN, but it's not officially "taller" until construction is completed. It's going to cost about $4 billion by the time it's done. In Kuwait, a 1001 meter building is in the works. The height is a reference to the classic work of Arabic literature, "One Thousand and One Nights." Three blades that will be built near the top of the tower will carry a mosque, a church and a synagogue to signify the unity of the three monotheistic religions. In Bahrain, there are plans in process for a building that is 1002 meters (3353 feet) tall with about 200 usable floors. This makes Bahrain the "Spinal Tap" of the middle east - making theirs "one louder."

But the Saudis are on their way to try to build the "Mile High Tower" in Jeddah, Saudi Arabia (a conceptual sketch is shown here). It will literally be a mile high - 5260 feet - with an estimated 375 floors and electromagnetic elevators. I've seen estimated budgets for this gigantic structure ranging from $10 billion to $45 billion. If they can pull this off, I'll be amazed. What is the limiting factor in tall buildings? Weight? Resistance to wind loads? Material capabilities? Crane/lifting capacity? Is there a limit? As an engineer, and this is fascinating to me. This is totally awesome, and I look forward to seeing this thing built. Why? To see if it can be done. Do you think the price of oil has anything to do with this building boom?

If the Mile High Tower is built, perhaps they can have a suite on the top floor where customers can join the "Mile High Club" without getting on a plane. "Mile High Suites" could be made available for hourly rental.