A century ago, suspended monorails were serious mass-transit contenders

If you’ve ever sped through the air on a suspended monorail, chances are you were in an amusement park, taking in views festooned with rides, animals, and manicured grounds. But it’s more likely that your first sky-car experience—assuming you’ve had one—was in an aerial tramway or cable car, gliding over steep terrain toward a tourist overlook perched atop a hard-to-reach peak. Whether it’s that strong association with park-like settings or simply the thrill of riding high with a bird’s-eye view, there’s something inherently recreational about aerial railways.

But as editor Arthur Stuart reported in Popular Science in May 1925, suspended monorails, or aero-railways, in which the train swings freely from an overhead track, were not limited to amusement parks and mountainsides; a century ago, they were serious mass-transit contenders in cities around the world. Despite their appeal, with few exceptions, commuting above the congestion of city streets gave way in the 20th century to more practical terrestrial and subterranean alternatives. Today, only one suspended monorail, the Wuppertal Schwebebahn in Germany, has survived since the turn of the last century—though not without incident. When an elephant jumped from the Wuppertal train in 1950, plunging into the river 10 meters below , service on the suspended train was, well, suspended for a year. The elephant, on the other hand, survived with minor bruises.

Excitable pachyderms notwithstanding, the technical complexities of suspended monorails—particularly their vulnerability to weather conditions, difficulty in switching tracks, and structural requirements—made them suitable only for niche applications. Ground-based trains and subways proved more stable, energy-efficient, and easier to integrate with existing infrastructure than suspended systems. But as modern cities grow denser and struggle to reclaim natural terrain to make their communities more livable, aero railways, with their smaller footprint, potentially lower cost, and quieter operation, may be worth another look.

The suspended monorail system described by Stuart in 1925 would have run from Paris to a nearby suburb, St. Denis. Its inventor, Francis Laur, had been tinkering with its unique design for more than a decade. “The proposed car,” Stuart wrote, would be virtually a propeller-driven airship suspended from and running along a rail. It’s [sic] body, tapering off at both ends like a dirigible, would be built of duralumin, extremely light.” While it had not yet been built, according to Stuart, its design had been “examined by expert engineers, and found to be practicable.” Just six years earlier, however, Popular Science’s coverage of Laur’s invention had been much less sanguine: “It is the offspring of ‘airplane’ and ‘monorail,’ two young ideas sprouting wild shoots in a lively imagination.” Just in case readers didn’t get the point, the 1919 staff writer added, “The Laur monorail flier does not figure out well financially or aeronautically.” 

Laur’s monorail never took off. In fact, the only propeller-powered monorail that ever progressed beyond the “lively imagination” stage was the Bennie Railplane. In 1929, George Bennie, an engineer from Scotland, debuted a propeller-powered monorail, or railplane, on a test track in Glasgow. Bennie envisioned his railplane running from London to Paris—with a seaplane to carry passengers over the English Channel—but his project, like Laur’s, never got off the ground.

Japan holds the modern record for the longest suspended railway, the Chiba Urban Monorail, which runs for 15.2 km and has been operating since 1988 in Chiba prefecture, east of Tokyo. But if Japan gets credit for the longest suspended railway, perhaps the most unique design concept goes to Hamburg, Germany’s Cabintaxi. As writer David Stuart reported in Popular Science in 1980, “cars run above and below the slim, lofty beam,” in a “personalized urban conveyor with a difference.” The project never materialized beyond a demonstration track, but the idea was that a car could be called to a station by a passenger, like hailing a taxi or booking an Uber ride. Depending on the direction, the car would either ride on top of the track or suspended below it.

Despite the failure of suspended railways to take root in 20th-century mass-transit systems, the 21st century may offer new opportunities. According to a 2018 United Nations report, the rapid urbanization trend of recent decades is likely to continue, adding “2.5 billion to the world’s urban population by 2050.” As people migrate to cities, upgrading and expanding mass transit will play a key role in reducing congestion and emissions. But in densely built city centers already served by subways and surface rails, urban planners and mass transit engineers may need to dust off century-old concepts to leverage the airspace above city streets and waterways. 

In the US, the only suspended commuter systems currently in operation are the Roosevelt Island Tramway in New York, which began operating in 1976, and Oregon’s Portland Aerial Tram, but others are being considered. The Chicago Skyline project, still in a proposal stage, would run cable cars, or aerial gondolas, over iconic neighborhoods, connecting tourist sites with downtown transportation hubs. Engineers in Austin, Texas, have been kicking around an 8.7-mile urban gondola line, dubbed Wire One Austin, for several years. New York’s Roosevelt Island tram may one day have a companion if the East River Skyway ever lifts off, connecting Manhattan, Brooklyn, and Queens. In central Los Angeles, LA Aerial Rapid Transit, or LA ART, is an aerial gondola project that proposes to connect Los Angeles Union Station with Dodger Stadium. But LA ART is not Los Angeles’ first proposed aerial transit system. As writer John Ford reported in Popular Science in 1923, inventor Fletcher Felts designed a suspended monorail with electric-powered passenger cars that resembled torpedoes. The project was never approved, but anyone stuck in LA traffic today likely wishes it had been.

Urban planner and researcher Steven Dale launched a blog in 2009, the Gondola Project, that tracks aerial transit system projects around the world. The list does not include suspended monorails, but it captures a global trend toward leveraging aerial transit in dense cities, especially those with challenging terrain, to address transportation problems. 

Even if suspended mass transit systems do catch on, it’s unlikely you’ll ever have the chance to ride in an aero-railway powered by “a propeller turning at 2000 revolutions per minute,” as Stuart described in 1925—with the possible exception of visiting a steampunk-themed amusement park (there aren’t many). But if global trends continue, it is increasingly likely that you will soon have the opportunity to commute across a city in an aerial car, suspended by cables or a rail, perhaps enjoying a recreational moment in an otherwise busy workday. That is, if you haven’t already. 

 

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