Invented by Oerlikon in Switzerland and built in Freienbach, the Gyrobus was a cross between a bus and a trolleybus. Two Gyrobuses linked the towns of Yverdon-les-Bains and Grandson on Lake Neuchâtel, travelling back and forth over the few kilometres that separated them, meeting each other halfway.
The Gyrobuses were powered by flywheels. Charging rods were located in the two termini, supplying electric power to the flywheel motors which in turn rotated the steel disks, 1.6 metres in diameter, weighing one and a half tonnes and reaching their optimum speed of 3 thousand revolutions per minute.
Once the Gyrobus disconnected from the grid, the flywheel in turn provided electricity to two motors on the axles of the rear wheels. This meant you could travel six kilometres, with almost no noise, zero emissions and without the need for batteries onboard the vehicles. After the ten-minute journey the Gyrobus returned, ready for its 5-minute charge, just like a normal bus stopping at its terminus.