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Derechos | Equipo Nizkor
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| Information | | |
Derechos | Equipo Nizkor
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24Oct22
China’s ‘electromagnetic sled’ is almost supersonic
China has scored another first in high-speed railway technology. After operating the world's fastest commercial maglev train since 2003, China is now testing a much faster system that reportedly zooms at over 80% of the speed of sound.
Referred to as an "electromagnetic sled," the train has a top speed of 1,030 kilometers (640 miles) per hour. That's 2.4 times faster than the Shanghai Transrapid maglev train, which tops out at 431 kilometers per hour on a 30-kilometer elevated track to and from Shanghai Pudong International Airport.
The electromagnetic sled is being designed and built by the Institute of Electrical Engineering of the Chinese Academy of Sciences in cooperation with Shangdong province's Jinan City and provincial governments. The work is being done at a ground testing facility for high-mass, ultra-high-speed electromagnetic propulsion technology in Jinan City.
A China Global Television Network (CGTV) video shows a single car streaking down a straight track built on flat ground. Top speed can be attained with a total weight of a metric ton (1,000 kilograms) or more, according to reports.
In addition to high-speed ground transportation, tests of the system will likely contribute to China's wider research into aerodynamics, materials science, aerospace and perhaps even railguns.
The electromagnetic sled can travel about 1.7 times faster than the maglev train developed by the Central Japan Railway Company (JR Tokai), although the Japanese version is a proper train. In 2014, then-prime minister Shinzo Abe took then-US ambassador Caroline Kennedy for a ride on an experimental model in Yamanashi Prefecture west of Tokyo.
Maglev journey in time
A maglev train - or, in the terminology popularized by Japanese National Railways (JNR) engineer Yoshihiro Kyotani, a linear motor car - uses magnetic repulsion to lift the vehicle above the track and propel it forward. Superconducting electromagnets are located on the undercarriage of the cars and along the rails, or guideway.
Rubber wheels support the train when it is stopped or moving slowly. As it accelerates, the magnets interact and raise it 10 centimeters above the track, eliminating friction and enabling high speeds.
In the words of explainthatstuff.com, a linear motor is an "unwrapped" electric induction motor that generates motion in a straight line. In a traditional motor, the rotor spins inside the stator - the stationary part of the system. In a linear motor, the stator is laid out flat and the rotor moves along it in a straight line. Diagrams and more detail can be found here.
The idea of a linear motor maglev train is more than a century old. American rocket scientist Robert Goddard proposed the concept in 1909.
In the late 1940s, British electrical engineer Eric Laithwaite began to develop a working linear motor. He was later involved in the development of magnetic levitation and became known as the "father of maglev."
In 1966, American physicists Gordon Danby and James Powell published the first research paper on superconducting maglev railway technology while working at the Brookhaven National Laboratory. They received a patent for their invention in 1968.
JNR began investigating linear propulsion technology in 1962 with the goal of finding a way to travel from Tokyo to Osaka in only one hour. That was two years before the Shinkansen (Bullet Train) began operating between Tokyo and Shin-Osaka stations - just in time to showcase it for visitors to the 1964 Tokyo Olympics.
At first, the bullet-train trip from Tokyo to Osaka took about four hours. A year later, the travel time was down to three hours and 10 minutes. Today, the Nozomi Shinkansen, which stops at only four stations in between, makes the 552.6-kilometer trip in two hours and 25 minutes.
The maximum operating speed of the fastest Shinkansen train is now 320 kilometers per hour.
JNR developed its own superconducting maglev system over the course of a decade and carried out its first test successful run in 1972. When JNR was privatized in 1987, the project was inherited by one of the regional carriers, JR Tokai.
In 2011, the Japanese government granted permission for the construction of a maglev train line from Tokyo to Osaka. The train is now called SCMaglev (SC for superconducting).
In 2015, JR Tokai Chairman Emeritus Yoshiyuki Kasai and Japanese Minister of Land, Infrastructure, Transport and Tourism Keiichi Ishii went for a ride with then-US secretary of transportation Anthony Foxx, hoping to impress a prospective customer.
That same year, a seven-car Japanese maglev train set a speed record of 603 kilometers per hour. Videos from the Yamanashi Prefectural Maglev Exhibition Center can be seen here.
The plan is to connect Tokyo's Shinagawa station and Nagoya in 2027 with a travel time of 40 minutes and then extend the line to Osaka by 2037 with a total travel time of 67 minutes - close to the target set in 1962. Travel time to Nagoya on the Nozomi Shinkansen is currently 90 minutes.
The SCMaglev train to Nagoya and Osaka will have a maximum operating speed of 505 kilometers per hour and up to 16 cars with seats for about a thousand passengers. An addition to the Shinkansen network, it is likely to be used primarily by business travelers in a hurry who don't mind not having a view of Mount Fuji.
Of the total distance of 286 kilometers, 256.6 kilometers or 90% will be through tunnels under urban areas and mountains. In other words, it is as much a tunneling project as a maglev project, if not more so. Problems with boring machines and concern over the impact of tunneling on the flow of river water in Shizuoka Prefecture threaten the 2027 deadline.
China on a fast track
The first three Shanghai Transrapid maglev train sets were built in Germany by Siemens and ThyssenKrupp. The technology, developed for an urban monorail, was first demonstrated at the International Transportation Exhibition held in Hamburg in 1979.
The electrical system was designed by Vahle. The guideway was built by Chinese companies on thousands of concrete pilings driven as much as 70 meters into the alluvial soil of Pudong.
The Shanghai Transrapid was inaugurated in December 2002 by then-German chancellor Gerhard Schroder and then-Chinese premier Zhu Rongji. Operations began in October 2003. In 2010, a fourth train built by Chengdu Aircraft Industry was added to the system.
It is now likely that China will build many maglev trains - not as fast as the electromagnetic sled, but comparable in speed to Japan's SCMaglev - to augment what is now a high-speed rail network of more than 40,000 kilometers. That compares with not quite 3,500 kilometers of Shinkansen track in Japan, a much smaller country.
Given its large area, long distances, flat terrain in heavily populated areas and ability to implement infrastructure construction plans with dispatch, China may soon lead the world in maglev trains as well.
[Source: By Scott Foster, Asia Times, Bangkok, 24Oct22]
 | This document has been published on 06Nov21 by the Equipo Nizkor and Derechos Human Rights. In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes. |