Even though in railroad parlance the term coupling primarily refers to the elements used to connect the carriages to each other, a large number of torque-transmitting couplings are also required in this industry segment to influence the vibration behavior of the drives and to compensate for misalignments. The demands on reliability, for example of the misalignment couplings on the bogies, can best be illustrated by the fact that the ICE 4 consists of up to seven driven cars with a total of 28 couplings.
The highly flexible couplings in the power packs of the diesel-electric drive systems of the locomotives are much smaller in number but in no way less important for operation. Depending on the place of use, the permissible operating temperatures of the couplings are completely exhausted here, sometimes even within a single run.