These types are self-propelled and find their use in structures like towers or under-construction buildings. It is used mainly by maintenance crews and typically carries one person with equipment.
It uses pneumatic pressure for its operation. The pressure differential decides whether the elevator will go up or down.
General working of elevators :
If you know how a pulley works then chances are you already know how a common elevator works. In theory, it’s just a sophisticated pulley which can transport humans. A very strong steel rope is used to suspend the passenger car which goes up and down a sheave. Counterweights are employed to control the rate of ascent and descent along with powerful motors. Guided rails are also present and the car is also fitted with breaks which would bring the elevator to a halt in case of emergency. As a secondary safety measure a very strong and powerful spring is also installed at the bottom of the elevator shaft. This spring can break a direct fall keeping the elevator car safe.