Early escalator stairs made of wood. Since 1987, the London underground when the fire broke out at railway stations, most still use wooden steps were already converted into metal. Modern escalator cascade metal manufacture, each step is triangular brackets. Bottom bracket is level two axes, axis wheels. Two wheels on each side in a different orbit, and by changing the distance between the tracks, keep the cascade level. Each step scaffold wheel at the top of the hinge connection. Top comb under the sheet with the escalator motors, drive the hinge moves cascade. When cascade reached the end of the escalator, will be turned into a row of passengers left, then after combing, then go down the next, to the other direction, endless circle. Some new escalator side to glass, can clearly see the mechanical structure. As for handrails on both sides, is made with rubber, wheel drive, and you want to keep the speed consistent with cascade.
Most of the escalators are straight. 1985 Japan Mitsubishi Electric curve running the first invention, spiral escalators. In addition to saving space, spiral staircase is also very artistic effect. In addition, some escalators can be variable in the middle level. When using very long escalator can reduce the fear of height, can be more flexible with the construction.