An elevator or lift is a type of vertical transport equipment that moves people or goods between floors (levels, decks) of a building, vessel, or other structure. Elevators are generally powered by electric motors that either drive traction cables or counterweight systems like a hoist, or pump hydraulic fluid to raise a cylindrical piston like a jack. Elevators includes three basic types :
  • Machine-Roomless Elevators
  • This revolutionary elevator system is based on the first major breakthrough in lifting technology in nearly 100 years. Designed for buildings between two and 30 stories, this system employs a smaller sheave than conventional geared and gearless elevators. The reduced sheave size, together with a redesigned machine, allows the machine to be mounted within the hoistway itself - eliminating the need for a bulky machine room on the roof.

    Just as unique are the flat polyurethane-coated steel belts, an Otis invention for the Gen2 elevator system, that replace the heavy, woven steel cables that have been the industry standard since the 1800s. The belts make the smaller sheave possible. They are only 0.1 inch (3 mm) thick, yet they are as strong as woven steel cables and far more durable, flexible and space-saving.

  • Gearless Traction Elevators
  • In 1903, Otis introduced the design that would become the standard in the elevator industry - the gearless traction elevator. These elevators typically operate at speeds greater than 500 feet per minute (2.54 meters per second).

    In a gearless traction machine, woven steel cables called hoisting ropes are attached to the top of the elevator car and wrapped around the drive sheave in special grooves. The other ends of the cables are attached to a counterweight that moves up and down in the hoistway on its own guiderails. The combined weight of the elevator car and the counterweight presses the cables into the drive sheave grooves, providing the necessary traction as the sheave turns. Gearless technology makes the tallest buildings in the world possible, such as Malaysia's Petronas Towers.

  • Geared Traction Elevators
  • As the name implies, the electric motor in this design drives a gear-type reduction unit, which turns the hoisting sheave. While slower than a typical gearless elevator, the gear reduction offers the advantage of requiring a less powerful motor to turn the sheave. These elevators typically operate at speeds from 350 to 500 feet per minute (1.7 to 2.5 meters per second) and carry loads of up to 30,000 pounds (13,600 kgs). An electrically controlled brake between the motor and the reduction unit stops the elevator, holding the car at the desired floor level.


An escalator is a moving staircase a conveyor transport device for carrying people between floors of a building. The device consists of a motor-driven chain of individual, linked steps that move up or down on tracks, allowing the step treads to remain horizontal.

Escalators are used around the world to move pedestrian traffic in places where elevators would be impractical. Principal areas of usage include department stores, shopping malls, airports, transit systems, convention centers, hotels, arenas, stadiums, train stations (subways) and public buildings.


A moving walkway or travelators is a slow moving conveyor mechanism that transports people across a horizontal or inclined plane over a short to medium distance. Moving walkways can be used by standing or walking on them. They are often installed in pairs, one for each direction.