Modern high-rise buildings have sophisticated elevators that take users to the floor they want in a matter of minutes. New York’s 1 WTC, which opened for tenants in November, houses the Western Hemisphere’s fastest elevator system.

The observatory at 1World Trade Center (1WTC) in lower Manhattan offers visitors a spectacular 360-degree view of New York City and the surrounding area from nearly 390 meters above the busy streets. A 60-second ride in the elevator takes visitors to the upper reaches of the building.

The 104-story 1WTC has 71 elevators, including five express systems with a speed of more than 36.5 kilometers per hour. Powered by eight 2.3-ton electric motors, the high-speed elevators operate using a pulley like system that comprises a cab and counterweights connected by a cable. In total, the elevators at 1 WTC use around 454,000 kilograms of counterweight to ascend and descend the building’s hoistways or shafts. These accessibility systems also feature a wide range of advanced features and specifications that help improve safety and logistics.

The 1WTC elevators use an “active roller guide” system that keep the lift wheels or rollers in contact with the guide rails as the car ascends and descends. Made of polyurethane, the rollers have the ability to absorb slight imperfections in the rail joints and are controlled by a system that pushes and pulls against the rails to prevent any misalignments.

While designing and building high-speed elevator systems that can scale super tall skyscrapers, engineers must consider how changes in air pressure may impact the elevator cars and their passengers as well as the floors they pass. The elevator hoistway in 1WTC is kept at positive pressure in order to prevent smoke from entering the lift in the event of an emergency. The lift has an auxiliary door that leads to a separate corridor where users can go if the main part of a floor is not safe for them to exit from the main elevator door.

Generally, occupants of high-rises and skyscrapers are cautioned to never to use a lift during a fire or other emergency. However, this rule seems to be impractical in extremely tall buildings as most occupants may not be able to walk down 100 or more floors in time if all the elevators are recalled to the ground floor. Scientific American reports that James Fortune, Principal at Elevator Consultancy Fortune Shepler Saling in Galveston, Texas, recommends lifeboat operations in high-rise buildings where elevators could be switched to an evacuation mode, enabling responders to take them to designated floors such as sky lobbies so that they can be rescued.

Traffic management is a crucial part of elevator use in high-rise buildings. The elevator systems at 1 WTC rely on a kiosk setup in the lobby that determines which lift a particular visitor will ride. Destination dispatch system is used in about 63 of the building’s lifts to direct individuals to the appropriate car. People going to the same floor are grouped together for faster and more efficient service.