In this blog post, we will look at how reliable the safety devices of elevators, an essential means of transportation in our daily lives, are and what direction future technology will develop in.
If you live on a high floor of an apartment building, you may have experienced the inconvenience of a notice saying “Elevator inspection” several times a year. It is at times like these that we realize the importance of elevators. Without an elevator, going up and down just a few floors would be a great hassle, and it could be quite difficult to carry goods or transport patients urgently. Especially in an age when skyscrapers are everywhere, elevators have become more than just a convenience, but a key element of architectural design and building management. Without the invention of the elevator, the skyscrapers that are now appearing in various countries around the world would not have been possible.
The invention of the elevator can be seen as a symbol of the development of science and technology. The desire of humans to climb higher has continued throughout history, and from the initial method of simply moving through stairs, they gradually began to be assisted by mechanical devices. This process led to the creation of the modern elevator. The elevator uses the principle of a pulley. In the old days, in order to easily draw water from a well, wheels were hung from the ceiling and ropes were hung from them, with a gourd attached to one end of the rope and a handle attached to the other. If you pull the rope at the handle, you will see the gourd attached to the other end of the rope move up and down. This is a fixed pulley.
So how is the principle of this fixed pulley applied to elevators? To understand this, we must first know the structure of an elevator. The enclosed space where passengers board an elevator is called the “car.” And a fixed pulley and electric motor are installed on the ceiling at the top of the passageway where the elevator moves. A steel rope is hung from the fixed pulley, and at one end of the rope is a car, and at the other end is a counterweight that is similar to the weight of the elevator when no one is on board. The electric motor on the ceiling is responsible for winding the rope, which moves the car up and down. If the pulley is fixed like a gourd on the well, it would take a lot of force to wind the rope, but since a counterweight is suspended on the rope on the other side of the car, it can be moved up and down with little force.
An elevator is not just a device that moves people, but a complex system that includes various safety devices and scientific principles. In horror movies, there are often scenes in which the elevator rope breaks and people fall or the elevator malfunctions and an accident occurs. In reality, some people are afraid to ride an elevator because of accidents that occur in elevators. However, the probability of such accidents occurring in reality is said to be almost zero. This is because elevators have more than 20 built-in safety devices.
First of all, the ropes used in elevators are made of steel wires with 30 strands of steel wire bundled together, and the strength of the steel wires is 12 times the weight of the elevator at its maximum weight. In other words, there is little risk of the ropes breaking unless they are cut artificially. Even if the rope breaks due to wear or corrosion, the elevator will not free-fall. When the car’s descent speed increases to 1.3 times the design speed, the power is automatically cut off, and when it exceeds 1.4 times the design speed, the emergency stop device is activated to stop the car by directly engaging the rail. Even so, in case the elevator falls freely, there is a shock absorber at the bottom of the elevator shaft to cushion the impact. Thanks to these multi-layered safety devices, people can move around without anxiety even in high-rise buildings.
Elevators, which move people to each floor of a building, will continue to develop as more and more high-rise buildings are built in the future. The elevator technology of the future is expected to be much more innovative than the current one. The elevators that scientists are currently researching include elevators that move up along the rail without a rope, like a train that moves vertically, and elevators that move horizontally. Such elevators will play an important role in not only moving around high-rise buildings but also realizing the concept of a large-scale vertical city. In addition, the National Aeronautics and Space Administration (NASA) is planning to install an elevator that extends into space to transport spacecraft. After launching a satellite, a 96,000-kilometer train track will be installed to connect the satellite to the Earth. I look forward to the day when the scene from Roald Dahl’s novel “Charlie and the Great Glass Elevator” becomes a reality.
