A double-deck elevator system has two elevator cabs attached, with one on top of the other. This design allows passengers on consecutive floors to use the elevators at the same time, which increases capacity and reduces wait times. This is an important consideration in high-rise buildings with heavy traffic.
With a traditional elevator system, it could be necessary to stop on every floor. With a double-deck system, each cab can be assigned to either odd or even floors during peak times. This can cut the number of stops in half.
Some double-deck elevator systems do not transport two groups of passengers at the same time. Rather, one elevator cab moves passengers while the other is used to transport goods from one floor to another.
Double-deck elevators work in a way similar to trains. Both move passengers in connected cars using a single drive system.
Double-deck elevators are becoming increasingly popular in skyscrapers because they dramatically reduce the amount of space required for elevator shafts. This allows for better use of space and more room for offices, apartments, or other uses.
Double-deck elevators have been used in skyscrapers around the world. The 110-story Sears Tower in Chicago, which was completed in 1973, was the first skyscraper to utilize sky lobbies with double-deck elevators, as well as local single-deck elevators. The 88-story Petronas Towers in Kuala Lumpur, Malaysia were the first buildings to use all double-deck local elevators, as well as a single zone of double-deck shuttle elevators. The 101-floor Taipei Financial Center was the first building to use all double-deck local elevators and dual zone double-deck shuttle elevators.