Historically, elevators hung on cables, and that's why it was one per shaft. Pat...

Historically, elevators hung on cables, and that's why it was one per shaft. Paternosters put more weight on their hanging parts and probably have much more severe height limitations.

We're slowly starting to see elevators without cables, and this will probably influence tall buildings in the coming decades. https://www.youtube.com/watch?v=EJLlXwVLDH0