elevators

An elevator, or lift, is a vertical transportation device used to move people and goods between floors in buildings. It typically consists of a car suspended in a hoistway and guided by rails, driven by a motor that powers either a traction system with a counterweight and steel ropes or a hydraulic system using a piston and fluid. Traction elevators are common in tall buildings and often feature machine-roomless drives or gearless motors. Hydraulic elevators are used mainly for low- to mid-rise applications and favor smooth starts and stops in tight spaces.

Major components include the car, hoistway, guide rails, doors and landing doors, the counterweight (in traction systems), hoisting ropes or hydraulic ram, the drive or pump, and the control system. Safety devices such as overspeed governors, safeties, and door interlocks protect passengers, while the controller manages floor selection, door operations, and speed. Modern elevators may use regenerative drives and destination dispatching, which directs passengers to cars based on their destinations, and can be configured as machine-roomless to save space.

Elevator installations are governed by national and international standards and require regular inspections. Examples include ASME A17.1 in the United States and EN 81 in Europe. Safety features protect against overspeed, entrapment, and door hazards, and routine maintenance ensures cable integrity, hydraulic seals, and proper braking and door operation.

Typical capacities range from about 400 to 2,500 kilograms, with speeds roughly 0.5 to 6 meters per second. Elevators are designed to meet accessibility requirements and are subject to ongoing maintenance, modernization, and monitoring to improve efficiency, reliability, and ride comfort.

Modern elevators trace their development to 19th-century safety innovations by Elisha Otis, whose safety brake helped enable tall buildings.