Sears Tower

Now the Willis Tower, the Sears Tower was a testament to the technology limiting the effects of wind. The taller a building grows, the higher lateral forces the building must sustain. Some buildings would use cross-bracing as an effective method. The Sears tower uses nine interlaced tubes to prevent torque in the building. At the time of its design Sears was the largest department store in the world, and the owner decided the largest company needed the largest headquarters as well.