As the population in cities continues to increase; running out of ground on which to build places for people to live and work. The solution has been to build structures up, instead of out; however, walking up 50 flights of stairs is not for everyone, so having a way to easily and efficiently move people up and down is imperative. Escalators, elevators, ropeways and lifting equipment are machines that were specifically invented to accomplish this purpose. Escalators and elevators, the two most common lifting machines are based on simple concepts. Here is a quick explanation of the two.

Escalators are basically a modified conveyor system. An escalator consists of two chains (one on the left, one on the right) looped around two sets of gears; the top set of gears is attached to an electric motor, which turns the gears; steps are attached to the chains and as the chains move, so do the steps. The steps themselves are designed with grooves and hinges, which allow them to fold down on top of each other as they reach top (or bottom).

Elevators are another lifting machine based on a simple concept; ropes and pulleys were the moving part in the first elevators. Today’s elevators, though completely mechanised, still use that same concept. Steel cables are attached to the top of a heavy-duty metal box. When a passenger pushes a button, a signal is sent to the gears, which tells the elevator when to stop.

You can find more information about escalators, elevators, ropeway and lifting machines at the following sites.