In 2013, under the call of “Iron Man” Elon Musk, the concept of super high-speed rail (a type of vehicle operating in a vacuum pipe) It is widely known that it has become a hot spot for scientific research and social discussion in many countries in recent years. But in fact, similar ideas have been proposed as far back as 200 years ago. This article will briefly review the evolutionary history of vacuum pipeline transportation and give a glimpse into the past and present life of super high-speed rail.
One, pressure difference is motivation
The beginning of vacuum technology, there is an exact record in history is the Torrie disassembly experiment of 1643: you can find the pressure between the atmosphere and the vacuum in the sealed long tube filled with mercury and inverted in the mercury tank. Poor, able to lift 760 mm mercury column. The first case of the application of vacuum technology was the Madburgh hemisphere experiment in 1654: the two hemispheres were synthesized into a sphere of 119 cm in diameter, and the internal gas was evacuated by a vacuum pump. After that, 8 horses on each side could not be used. Pull away.
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Medberg Hemisphere Experiment
It can be said that these two well-known experiments both use the principle that there is a huge pressure difference between the atmosphere and vacuum [1], and it is also a proof that this pressure difference can generate mechanical forces. Later generations were also inspired by the transport items.
In 1799, a British mechanical engineer and inventor named George Medhurst applied for a patent for a fan pump powered by compressed air. The following year, he applied for a patent for a “wind-driven” engine that uses compressed air to drive the car. At the same time, he proposed a service plan for wind-driven cars and suggested that a pumping station be set up on the driving route to provide continuous power for him. Similar to electric vehicles and charging pilesRelationship.
Atmospheric Railway
Based on previous ideas, Medhurst proposed the idea of a vacuum mail line in 1810, and believed that this method of using air pressure to transfer letters and goods in the pipeline was faster and more efficient than postman delivering it from house to house. . Further, he began to imagine the possibility of transporting trains on larger pipelines.
In 1812, he published for the first time a theoretical calculation article on the atmospheric railway, demonstrating the feasibility, effect, and advantage of quickly transporting goods and passengers through the pressure difference by setting up a pipeline with a diameter of several meters above the rails.
In addition, he also conceived another form of atmospheric railway, that is, a long tube is laid under the rail, and the device in the pipeline is connected to the train. The device is driven by the pressure difference to drive the train. The source of power is not the front of the car, but the pipes under the car.
September 1827, shortly before his death, published the book “New Inland Transport System”, admiring aerodynamic propulsion. He believed that this method could reach 96 kilometers even without horses or other animals. Speed.
The atmospheric railway uses air pressure to move the car along the track instead of using the front of the car as power.
However, due to various reasons, the atmospheric railway has not been successfully implemented, and this idea has gradually been shelved.
Until 2018, a 89-year-old American engineer, Max Schlieger, made it a reality: he set up a track in his vineyard with a 30 cm diameter polyvinyl chloride tube between the rails. A pump is connected to the pipe to extract air from the pipe or inject air into the pipe. Under the effect of the air pressure difference, the “thrust car” in the pipeline drives the train connected with it through the magnet.
The results of this model, which is only one-sixth the size of the standard railway system, show that it can easily overcome the steep slopes that traditional trains cannot surpass, and the operation noise is lower, no overhead transmission lines are needed, and the pump can be used for renewable Energy driven.
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Max Schlieger’s Atmospheric Railway
Second, from old theory to science fiction to new theory
In more than a century after the death of Medhurst, the theoretical research of vacuum pipeline transportation has gradually deepened and improved. What’s more, this mode of transportation also shines in the emerging science fiction literature. The ideas in those works seem to be advanced, but in fact, from the timeline, they have to lag behind the theoretical research of scientists, and each has its own theoretical prototype.
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