levators

Elevators, also called lifts in some regions, are enclosed hoisting systems that transport people and goods between floors of a building. They operate within a vertical shaft and are powered by either traction machines with counterweights or hydraulic pistons. The modern elevator emerged from 19th-century advances in electric traction and safety systems, with Elisha Otis’s 1853 brake marking a turning point in acceptability and reliability.

There are two main technologies. Traction elevators use a motor-driven drum or sheave to move the car, which is balanced by a counterweight for efficiency. Hydraulic elevators raise the car by pushing it with a confined hydraulic piston, typically used in low-rise buildings. Newer designs, including machine-room-less (MRL) variants, integrate equipment into the hoistway to save space and reduce infrastructure requirements. Modern systems often employ variable-frequency drives and computer-controlled logic to optimize speed, stopping accuracy, and energy use.

Key components include the car, hoistway, and pit, along with the counterweight, hoisting machinery, braking system, overspeed governor, door interlocks, and landing calls. The safety system may include emergency power supplies, alarms, intercoms, and buffers at the bottom of the shaft. Doors must align and interlock securely to prevent access when the car is not present.

Standards and regulation vary by region but commonly involve certification, regular inspections, and adherence to codes such as ASME A17.1 in the United States and EN 81 in Europe. Accessibility requirements, routine maintenance, and modernization programs are integral to ensuring safety, reliability, and energy efficiency in elevator systems.