Although captive balloons belong to the oldest of aircrafts, the HighFlyer is a marvel of modern technology. With its 23 metre diameter, the balloon has a volume of 6,400 cubic metres – twice as much as that of the local Alster indoor swimming pool!
Filled with helium (non-flammable), the balloon is capable of lifting 4.5 tonnes – more than enough to lift up its own weight, that of the gondola and 30 persons. A 22 mm wide steel cable securely connects the balloon to the ground. Despite having only the same thickness as that of a thumb, the cable is completely safe, ie. the rope can withstand a weight of up to 4.5 tonnes.
The 150 m long cable is connected to a cable winch on the ground, which is controlled by the pilots per remote control. For safety reasons, there is a second set of controls on the ground as well as an emergency power-generating set, which is automatically activated if there is a power failure. As a third option, the steel cable can also be controlled manually.