Maglev: the history and physics behind frictionless train transportation
Danny Liang
Introduction
Newton’s third law, ‘ For every force in nature there is an equal and opposite reaction ’ , is the crux of the reason why resistive forces such as friction and drag exist. In most cases, engineers are constantly working to eliminate them, as more energy is required to overcome them. In train transportation, friction between the vehicle and the rail creates unnecessary heat, slowing the train down and wearing its components down. The solution to this problem is the maglev (magnetic levitation) system, which completely removes friction by avoiding direct contact between the train and the rail. As the name implies, the system uses electromagnets, specifically two sets of them: one used to repel and lift the train, while the other moves the train along the track. Unlike any other existing ground transportation system, maglev takes advantage of a frictionless environment. This unique asset of the maglev has shown promising potential to be faster and smoother than other conventional alternatives. Despite still being in the early stages of major developments around the world, it presents us a new pathway to the future in transportation technology and clean energy transport.
History and development of the Maglev
The invention of the first maglev system originated with Albert C. Albertson in the United States in 1902. 1 He was the first to employ magnets in a way that reduced the weight and friction of a vehicle on a track. In his patent, the system was described as having a track rail and a supporting armature rail. Electromagnets were placed at the bottom of the vehicle, the poles of which pointed directly upwards and with their faces in contact with the smooth undersurface of the armature rail (see figure 1). Under the armature rail, there were also groups of electromagnets resting to repel the ones under the vehicle, creating a lifting force that supports the weight of the vehicle. 2 The principle was simple: as the lifting force nullifies the weight of the vehicle, it thereby decreases the overall pressure on the rails, which in turn also decreases the friction on the vehicle from the equation F = μ x R. While Albertson invented multiple variations of the design, conventional propulsion was used to move the vehicle forward as the linear induction motor had not yet been implemented.
Figure 1: The first page of Albertson's patent illustrating the levitation of a car from the railway using magnets .
1 https://youthtimemag.com/worlds-first-maglev-suspension-monorail; consulted: 26/7/2023. 2 https://patents.google.com/patent/US714851; consulted: 26/7/2023.
276
Made with FlippingBook - PDF hosting