Maglevs: How Do They Work?
As noted by Railway Technology, maglev got its start in the 1940s with British electrical engineer Eric Laithwaite — sometimes called the “father of maglev” — who envisioned mechanically simple trains operating with no rail contact, high efficiency and very low noise.
The first patent for a maglev train was issued in the 1960s to James Powell and Gordon Danby. According to Energy.gov, the basic concept is simple: Magnets on the bottom of train cars interact with magnetic “guideways” on the track to both keep the train car stable and propel it forward.
In practice, things are more complicated: Superconducting magnets cooled to -450 degrees Fahrenheit are required to generate powerful magnetic fields. The magnets push off “like” poles to levitate the train five inches off the track and also keep it stable horizontally, while AC-powered magnetic loops set in the walls of the track use both opposite and like poles to push and pull the train forward.
When stopped, the trains rest on rubber wheels and must reach speeds of 93 miles per hour before the magnetic force is strong enough to produce lift. At top speed, maglev trains can reach 375 miles per hour.
An Attractive Option
Maglev technology offers a number of benefits over traditional steel-track trains, including:
Improved Speed:In Japan, the Linimo commmuter line runs at 100 km/hr and can accelerate 1.5 times faster than a bullet train. As noted by Japan Rail Pass, a new maglev train being developed for the Chuo Shinkansen line reached the 375 miles per hour mark in 2015 — this 177-mile link between Tokyo and Nagoya is slated to open in 2027 and carry up to 1,000 passengers.
Reduced Maintenance: Maglev vehicles touch guideways only briefly and with rubber wheels. No engines are required to drive magnetic trains and the concrete guideways are largely unaffected by weather. The result? Minimal maintenance is required to keep magnetic vehicles up-and-running. While care is required to maintain the superconducting magnets’ liquid helium cooling system and their nitrogen-cooled radiation shields, the lack of physical track contact significantly extends their lifespan.
Enhanced Safety: Derailing is virtually impossible since the magnetic “push” generated like poles rapidly increases if trains shift away from guideway centers. Controlling speed is also more precise since no drivers are required — magnetic field intensity directly translates to forward momentum. History bears out this potential: In 60 years of operation, Japan’s maglev service has reported zero fatal accidents.
Minimal Noise and Vibration: Without metal-on-metal contact, maglev vehicles are extremely quiet and smooth. There are no screeching breaks, no grinding turns and no unexpected bumps due to strong winds, rainstorms or debris on the tracks.
If maglev technology is so magnificent, why aren’t superconducting high-speed rail lines standard? What keeps magnets from making progress?
Cost is the biggest challenge: As noted by the Japan Times, the Tokaido Shinkansne Bypass (expected to open in 2047) will cost $83 billion to build. According to the Baltimore Sun, work on a smaller-scale line in the United States is currently under review. While the potential here is a trip from Washington to Baltimore in 15 minutes, just the section that runs through Maryland could cost between $12 and $15 billion — if everything goes according to plan.
The other problem? As noted by Lawrence Blow, founder of consulting group MaglevTransport and quoted in the Railway Technology piece, “Maglev is a competitor to automobiles, trains and airplanes, as well as buses and metro-systems. It has many natural enemies but no natural friends.” To make a maglev line viable, professor Roger Goodall of Loughborough University says three criteria must be met:
There must be a large “megacity” at both ends. This ensures enough people ride the line to offset the cost.
The distance between these cites must be approximately 500 miles. Any closer and the speed of magnetic trains isn’t necessary. Any farther and air travel becomes preferable.
There must be no existing railway line.If a traditional line exists, upgrading and maintaining it is far more cost-effective than building a new maglev system.
From bullet trains to supersonic air travel, flying cars and autonomous vehicles, transportation innovation is picking up speed. The result? A renewed interest in maglev technology — and not just for trains.
As noted by Popular Mechanics, potential maglev options include StarTram, a mountainside space launch system that could allow vehicles to reach 18,000 miles per hour and SkyTran, which posits private pods suspended from an elevated guideway that whisks passengers along (safely) at up to 150 miles per hour. Magnetically-driven wind turbines could reduce friction and allow energy capture from winds of just five feet per second, bringing the price of wind power on par with coal.
More ambitious ideas include the “Heaven and Earth” concept for floating cities — using massive superconducting magnetic and Earth’s own magnetic field, these supercities would hover in air miles above the ground. Realistic? Probably not. Innovative? Absolutely.
The Future Is Frictionless
Maglev technology remains an innovation outlier but as materials improve and costs come down the benefits of speedy, safe and silent transportation may outweigh the natural repulsion of billion-dollar price tags to replace or augment existing rails — and help spur new growth across both vehicular automation and space transportation.