There was a time when the future of trains wasn’t on the tracks but floating above them, with friction a distant memory and speed as soft as a breeze. It was a dazzling future that made you smile with the certainty that humanity had done it again: conquered space and time through sheer ingenuity. Now imagine that future wasn’t science fiction but a tangible reality of concrete and metal, built in 1960s France. Then imagine it simply disappearing. Not because of a catastrophe or a war, but because technological brilliance isn’t always enough to convince practical people in suits.
That was the story of the Aerotrain, one of those marvels that makes you wonder why we put it away in the drawer marked “too good to be true.”
To set the mood, here’s a video document capturing the spirit—and sound—of that promise: a machine that didn’t roll, but glided.
A future that floated: Jean Bertin’s bold idea
To see what this marvel looked like in motion, there’s nothing better than watching the archival footage that captured its audacity:
In the postwar boom, as the world caught its breath and nations competed to offer the next big thing, a French engineer named Jean Bertin had an idea as simple as it was revolutionary: why not make trains levitate? If a hovercraft could glide over water, why not a train riding on a cushion of air above a concrete guideway?
This wasn’t a whim. Bertin and his team at the Société de l’Aérotrain didn’t just dream; they got to work with almost poetic determination. They built models, tested prototypes, and gradually the unthinkable began to take shape. The premise was elegant: eliminate friction between wheels and rails—the old enemy of speed—and achieve performance worthy of a spacecraft.
The 1960s, with their thirst for progress and futuristic optimism, were perfect for projects like this. France, eager to lead in engineering and design, saw the Aerotrain as a golden opportunity to put itself at the forefront of global transportation. The concept was undeniably mind-blowing.
Dream speed: when the Aerotrain touched the sky without touching the ground
For many, the real Aerotrain began to take shape on an 11-mile test track between Gometz-la-Ville and Limours, in the Essonne department south of Paris. A concrete monorail rose across the French countryside like a futuristic serpent—the stage for dreams of levitation.
Early prototypes, such as the Aérotrain 01 and 02, looked as if they’d come from a science-fiction movie. Powered by turbines—or, in the 02’s case, an aircraft turbofan—these lightweight, aerodynamic vehicles showed that Bertin’s idea was no fantasy. The tests were spectacular:
- The Aérotrain 01 reached 214 mph in 1967.
- A year later, the Aérotrain 02 broke 249 mph, reaching an astonishing 262 mph.
Imagine seeing that: a vehicle with no wheels, hovering inches above the concrete and gliding at airliner speeds with a roar that promised to change the world. Period audiovisual archives show it in action. It seemed the future had arrived, and it was French.
The high point came with the I80-HV (short for “interurban, 80 seats, high speed”), a much larger model closer to a real passenger train, powered by a ducted propeller. Then came the I80-250, which used an electric linear induction motor, reducing noise and dependence on fossil fuels. On March 5, 1974, it set a world speed record for a rail vehicle riding on an air cushion: 267.4 mph. The demonstration was clear: the Aerotrain worked—and worked beautifully.
The hard truth: why isn’t genius enough?
In the real world, though, technological brilliance often collides with practical constraints and, above all, economics. While the Aerotrain glided on its cushion of air, other engineers weren’t standing still. Another technology, less glamorous but firmly grounded—on rails, in this case—was gaining momentum: the high-speed train (TGV).
The Aerotrain’s advantages were undeniable: speed, a smooth ride with fewer vibrations, and potentially less mechanical-contact maintenance. But its disadvantages were hard to ignore:
- Dedicated infrastructure: The Aerotrain needed its own elevated concrete guideways, completely separate from the existing rail network. Construction costs would be astronomical, and integrating it into cities would require massive public works.
- Noise and pollution: Turbine- or propeller-powered versions were predictably loud. Engineers worked on electric linear motors to reduce the problem, but noise remained a challenge.
- Energy use: Maintaining the air cushion and propelling the train at high speeds required considerable energy.
- A specialized service: It could be extraordinarily fast between two points, but lacked the flexibility of conventional rail to serve intermediate stations without slowing the whole service.
Clash of the titans: Aerotrain vs. TGV
While the Aerotrain kept breaking records, the high-speed TGV project advanced quickly. Its technology was more conservative—it still used wheels and rails—but its big advantage was adaptability: it could use sections of the existing rail network, albeit at lower speeds, cutting infrastructure costs dramatically and making integration easier.
The timing was ironic. In 1974, just after the Aerotrain set its speed record, the French government made a consequential decision: plans for a commercial Aerotrain line between Paris and Orléans were canceled. The reasons included economic factors, a change in the transport minister, and the government’s decision to prioritize the TGV. In other words, the project had proved it could fly, but not that it was the most practical way to move people.
The Aerotrain’s story is a reminder that a technological breakthrough must do more than work in a test run. It has to fit into a larger system, make economic sense, and win public and political support. France chose the TGV, which went on to transform high-speed rail. The Aerotrain remained a remarkable glimpse of an alternate future—and a lesson in how even a brilliant invention can be left behind.