To achieve a speed of 1000km per hour, how far has China's super high-speed rail

Below the Pavement

Recently, the domestic "vehicle-road-cloud" concept has been booming in the secondary market with several high-value investment projects. Coupled with the news that Tesla's FSD (Full Self-Driving) is approaching its entry into China, the "vehicle-road-cloud" or "vehicle-road coordination" has reached a new climax this year, along with the more familiar single-vehicle intelligence. However, in the future city, in addition to intelligent driving on the ground and low-altitude flight, there may be other modes of transportation, such as the "Hyperloop."

Eleven years ago, Musk, who was already well-known in the tech circle, brought the concept of Hyperloop, which he had proposed for a long time, to the table and invited ambitious individuals to explore it together. In his publicly released 57-page design document, the so-called Hyperloop is intended to transport aerodynamic vehicles at aviation speeds through nearly vacuum tubes, carrying people or goods at a top speed of 800 miles per hour (1287 kilometers). These tubes can either be suspended in the air or buried underground—one could imagine it as the world's fastest maglev train, only it would operate at high speeds within a vacuum tube.

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Musk also did some calculations; if the Hyperloop were to carry only passengers, the cost would be just $6 billion, and if it were to carry people, goods, and vehicles, the cost would be $7.5 billion. The main difference lies in the choice of transportation and the construction of the tunnel. However, he also indicated that this mode of transportation is only suitable for cities less than 1000 miles (1609 kilometers) apart, as flying would be more appropriate for longer distances.

At the time, public opinion was quite skeptical, as a careful consideration reveals that a speed of 800 miles per hour is already on par with the speed of sound. If this concept were to become a reality, it would take only 30 minutes to travel from Los Angeles to San Francisco, which is twice as fast as a regular commercial jet and four times faster than a train.

Yet, it does have the potential to be realized, although it was not Musk himself who initially put this concept into practice.Domestic Hyperloop Prototypes Have Long Been in the Making

In 2014, well-known Silicon Valley investor Pishevar and former SpaceX engineer BamBrogan, among others, jointly founded the hyperloop startup "Hyperloop One." Two years later, Hyperloop One conducted its first test in the Nevada desert in the United States, reaching a speed of 180 kilometers per hour within two seconds; in 2017, it completed the world's first full-system hyperloop test on a 500-meter long, 3.3-meter diameter vacuum test track, with a top speed of approximately 310 kilometers per hour, achieving zero to one hundred acceleration in 1.9 seconds.

Another technology enthusiast with "money power," Sir Richard Branson, the founder of the Virgin Group, immediately invested in the company after the successful test of Hyperloop One, renaming it Virgin Hyperloop.

Unfortunately, the planned construction projects at that time did not proceed further, such as Virgin Hyperloop's original plan to build a hyperloop connecting Dubai and Abu Dhabi. If completed, the theoretical journey that would take over an hour could be reduced to 12 minutes. Even by the end of 2022, after spending nearly a billion dollars, the company was on the verge of collapse, and there were still no projects officially started or operational anywhere in the world. The highest speed achieved in Virgin Hyperloop's only manned test was only 100 miles (161 kilometers) per hour, far below the initial vision.

However, the manned test in 2020 is still considered an important milestone for the "hyperloop" concept. Although there were only two passengers, they traveled 535 meters at a speed of 107 miles (172 kilometers) per hour in a transportation system based on maglev tracks and vacuum steel pipes, and the experience ended in just 15 seconds.

In addition to Virgin Hyperloop, the Japanese academic community and the Canadian company TransPod have also targeted the hyperloop, but they have all been more talk than action. Setting aside costs and funding, there is still no consensus on the technical approach.

But in China, where the railway network is more complete and the country is more adept at transportation infrastructure, the practical application of the hyperloop has quietly taken the lead.

In February of this year, the Third Academy of China Aerospace Science and Industry Corporation completed a stable suspension test of a superconducting maglev "high-speed train" in a low-vacuum pipeline on the experimental line in Datong, Shanxi. In this 2-kilometer long experimental line with a pipeline diameter of nearly 6 meters, they set a new speed record, and also verified the good coordination of the vehicle, pipeline, and track, as well as a powerful propulsion system and safety control system, laying a technical foundation for the future hyperloop with speeds of over a thousand kilometers per hour.Although there are no specific data, considering that this superconducting maglev test line, which was completed last November, is currently the longest and largest super high-speed railway test line in the world, there is still a long way to go, and the experiments should still be in the initial stage.

However, the technological path of our country is relatively clear, and it is also the "maglev + low vacuum" model in the general direction. Maglev is a train system different from the wheel-rail system of high-speed trains. Chen Jiangong, an expert from the School of Civil Engineering at Chongqing University, introduced that since the traction force of maglev trains is electromagnetic force rather than friction force, compared with wheel-rail high-speed trains, the main advantages of high-speed maglev are faster speed, lower energy consumption, lower resistance, and less wear on the line. But the power of the train can come from electromagnetic force, or it can come from high-temperature superconductivity.

High-temperature superconducting high-speed maglev is another technological path of maglev, and its main difference from electromagnetic suspension technology is that it relies on liquid nitrogen rather than power supply to achieve suspension and driving. Southwest Jiaotong University, a leader in China's high-speed railway technology research and development, has been focusing on this field since 1997. With the progress of superconducting materials, technological research and development will definitely accelerate iteration.

Another technological focus is to maintain the vacuum of the pipeline. Musk's idea is relatively simple: to extract a vacuum from the pipeline, to suspend the transportation capsule with maglev technology, and to provide power with a turbine at the rear of the transportation capsule. "Because the resistance of the train moving forward is very small, so only a very small power can make the train obtain high speed."

But in reality, if this system is to be used for carrying people, then while maintaining the vacuum of the pipeline, it is necessary to ensure the pressure increase and oxygen supply in the transportation capsule, and also to consider the detailed process of passengers getting on and off the train. How to maintain a vacuum state in a high-temperature and high-pressure environment, and how to achieve the safe stopping and starting of high-speed trains are still to be discussed.

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From concept to commercial promotion

It is not enough to focus on technology alone, and the maturity of investment, policy support, and business models is indispensable. Otherwise, Musk would not have recognized the difficulty of commercializing this model after announcing his own conceptual design blueprint, and turned to a more pragmatic urban tunnel plan, rather than pursuing high speed at the beginning.

The Boring Company founded by Musk can no longer be called "super high-speed railway", but "tunnel transportation". The Boring Company claims to build a brand new three-dimensional underground rail transit system, allowing the space of the city to have infinite extension possibilities, using traditional tunnel technology, and the cost is far lower than the construction cost of Virgin Super High-Speed Railway, which is $84 million to $121 million per mile.However, the issue is that the only tunnel system currently in full operation is the loop established in Las Vegas, Nevada, and it is only compatible with Tesla vehicles; cars from other brands are not compatible at all. Even so, the Las Vegas loop, which was completed in 2021, has already successfully transported over 2 million passengers, making it a typical case.

The Las Vegas loop currently has five stations, including the airport. In the initial plan, the loop was supposed to be an underground transportation system with 29 miles of tunnels and 51 stations, but it is now planned to be expanded to 65 miles and 69 stations.

How are these vehicles transported? Initially, TBC designed an electric sled transportation plan, placing vehicles on a sled-like transport board that travels through the tunnel at a speed of 200 km/h. When it reaches a station, a device similar to an elevator shaft is used to lift the car up. Later, they changed to a system where cars are equipped with guide wheels, allowing them to drive in the tunnel like all-terrain vehicles, but this method required drivers to pay for the addition themselves, and the experience during turns was not satisfactory, so it was abandoned.

Currently, cars in the tunnel mainly travel using FSD (Tesla's Full Self-Driving technology). But what if FSD fails in the narrow tunnel? How would congestion be cleared after an accident occurs?

The key to TBC's project success is not just relying on government subsidies and private investments in the business model, but rather collaborating with local governments to jointly invest and operate. However, looking at it now, TBC's greatest potential may not be in establishing a three-dimensional transportation network, but in tunneling. Unlike the tunnels required for current subways, Musk is digging "small tunnels" with a diameter of 12 feet (about 3.7 meters) and using his own improved tunnel boring machines, allowing TBC to build tunnels faster and cheaper than any other company. But the timeline for upgrading from "small tunnels" to "hyperloop" is uncertain.