In 1974, a French train sets a speed record, exceeding 250 miles per hour. But this train is unlike any other before it. Instead of rolling on train wheels, it hovers on a cushion of air.
In the 1970’s hovertrains were seriously being considered the solution to slow, antiquated railways, which increasingly had to compete with new superhighways and even intercity air travel.
Without the rolling resistance of train wheels, hovertrains promised greater efficiency and much higher speeds. By feeding high pressure air through lifting pads, hovertrains float on a cushion of air much like a hovercraft.
One of the most widely known hovertrain prototypes was called the Aerotrain. Lead engineer Jean Bertin and his team in France, designed several versions, including one that could carry 80 passengers. The i80HV was powered by a turbofan sourced from an airliner, producing over twelve thousand pounds of thrust. At the front, a 400 horse power gas-turbine supplied high-pressure air to hover the twenty loaded train a quarter of an inch off its guideway.
The British and Americans also experimented with hovertrain technology, incorporating the linear induction motor for improved efficiency. British research led to the development of the RTV-31 Tracked Hovercraft, and the American’s developed several prototypes, culminating in the development of the Urban Tracked Air Cushion Vehicle (UTACV).
But like their counterpart the Maglev, Hovertrains failed to revolutionize rail. Hovertrains, Maglevs, or any other innovative alternative to rail has to compete with nearly a million miles of rail line already in existence. With stations and infrastructure built-out in nearly every city in the world.
The limitations of conventional railways were overcome not a single innovative leap forward, but by incremental improvements. Existing rail networks were modernized with sections of track that could handle higher speeds. New signaling technologies were developed along with more advanced wheelsets.