Page "Hovercraft" Paragraph 26

Another discovery was that the total amount of air needed to lift the craft was a function of the roughness of the surface it traveled over.

On flat surfaces, like pavement, the needed air pressure was so low that hovercraft were able to compete in energy terms with conventional systems like steel wheels.

However, as the hovercraft lift system acted as both a lift and very effective suspension, it naturally lent itself to high-speed use where conventional suspension systems were considered too complex.

This led to a variety of " hovertrain " proposals during the 1960s, including England's Tracked Hovercraft and France's Aérotrain.

In the U. S., Rohr Inc. and Garrett both took out licenses to develop local versions of the Aérotrain.

These designs competed with maglev systems in the high-speed arena, where their primary advantage was the very " low tech " tracks they needed.

On the downside, the air blowing out from under the trains presented a unique problem in stations, and interest in them waned in the 1970s.