What Are The Origins Of The Hovercraft?

About fiftty years ago an electronics engineer made a rough experimental model with the aid of two empty coffee cans, one slightly smaller than the other, and a small industrial blower rather like a home hair dryer. The engineer, Christopher Cockrell, took the larger can and drilled a hole in its base just large enough to take the nozzle of the industrial blower. Next, he fixed the smaller can inside the larger can so that a gap was left between the two walls. Now, with the can bases facing each other, any air blown from the nozzle must be diverted down through the gap between the sides of the cans to emerge as a ring-shaped curtain of air, only a fraction of an inch thick.

The contraption was fixed to a stand so that the pressurized curtain of air could be directed down onto the weighing pan of a pair of domestic kitchen scales. Cockrell now had a crude method of measuring the pressure of the air leaving the cans. As he expected, the air pressure leaving the industrial blower nozzle had more than tripled during its passage through the gap. From this, Cockrell concluded that a curtain of air so produced, if directed onto a solid base, would not only support the weight of the producing unit but also carry an additional load. Further, if some method of propulsion could be added, the unit, plus a load, would move quite safely on a controlled cushion of air in any direction. This marked the birth of the air-cushion vehicle (ACV), from which the hovercraft and many other devices originated.