Living-Room Levitation

By Gregory T PopeJun 1, 1993 5:00 AM


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Robert Lawrence wants the United States to take back maglev technology. That’s why your next model railroad may have a magnetic personality.

In 1996, if all goes according to plan, magnetically levitating trains will start whisking tourists around Orlando, Florida. For most Americans it will be the first taste of maglev technology, with its promise of 300-mph locomotives hovering above a track. But if Robert J. Lawrence has his way, you won’t have to wait three years to reap the rewards of magnetic levitation. You won’t even have to leave home.

That’s because Lawrence, a retired electrical engineer and unabashed maglev buff, plans to sell toy maglevs to the nation’s legion of model-railroad enthusiasts. But there’s more to his enterprise than entertainment. The purpose is to get the public familiar with and behind maglev, he says. We’re in a battle to win this technology back for America.

Although two American physicists, James Powell and Gordon Danby, secured superconducting maglev patents in 1968, since then only Japan and Germany have exploited their efforts. Each nation has bankrolled working prototypes to the tune of at least $1 billion. Germany has a 275-mph, two- car train that runs on a 20-mile test track, while Japan has a 300-mph, one-car train operating on a 4.3-mile track. The Orlando maglev is harnessing the German design.

Two years ago the U.S. Department of Transportation finally had the funds to solicit competing maglev designs from four American firms. It is these four blueprints, submitted last October, that Lawrence plans to model faithfully at a scale of 1 to 50. The two-car train will be about 28 inches long and will sell to hobbyists for $2,000 to $5,000. For mass consumption, he also plans to introduce a $200, 1-to-100 scale model.

His plans call for putting garden-variety magnets on the underside of each car and winding electric coils through the tracks. When charged, the coils will radiate electromagnetic fields that repel the train magnets, levitating the vehicle.

To propel the train, household current, which alternates at 60 times per second, will flow through a control box and then on to the coils in the track. The alternating current reverses each successive track coil from positive to negative polarity, pulling the train magnets along the track and thereby creating a traveling magnetic wave. The faster the current alternates (the speed is controlled by the box), the faster the train moves. Separate circuitry will chop up the current, charging only isolated three-foot stretches of track in front of the moving cars so that other trains in the set may stand still.

The model trains will hover as little as one-tenth of an inch over the track. With such a slim gap, bulges or other imperfections in the track could easily scrape a train’s belly. To avoid such friction, sensors in the cars will measure clearance. If the clearance suddenly tightens, the sensor will mete out additional electric current to another set of small electromagnets mounted under the train, which will provide more levitating power. Real-life maglevs rely on similar systems.

Two of the hobbyist models will even have a body-tilting mechanism like their full-scale counterparts. The machinery banks the passenger cabin relative to the undercarriage to keep riders from lurching sideways during curves. Hydraulic cylinders tilt cabins in real maglevs, while simple magnetic devices will do the job for the toys.

Such sophistication will certainly eclipse the simple mechanics of a traditional toy train set. We’re going way beyond what your Lionel trains can do, notes Lawrence. Conventional model trains can’t climb steep slopes because their wheels slip. Freed from the need for wheel-on-rail traction, Lawrence’s toys will someday turn topsy-turvy in barrel rolls and loops. He’ll restrict these tricks to the $200 line, since the hobbyist line is supposed to model authentic maglevs, which would hardly subject passengers to roller-coaster maneuvers.

It appears Lawrence is well on his way: he’s working to raise $12 million in capital and negotiating to buy an electronics assembly plant, and he has a technical advisory panel in place. It also appears the future may finally be brightening for the real maglev. For despite tough budgetary times in Washington, the new administration is backing maglev development. Could it finally mean that someday we will find maglevs floating outside, as well as inside, American homes?

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