Abstract: A bridging device for hydrodynamic hydraulic couplings (1), more particularly for turbo couplings of variable or constant filling, which couple a prime mover to a machine and whose input shaft (5) can be coupled by means of the bridging device (D), having a force-transmitting device (11), to its output shaft (8) to increase efficiency of transmission. The force-transmitting device (11) of the bridging device (D) is uncoupled from the rotary motion of the hydraulic coupling (1) and can be controlled by means of a control device disposed outside the casing (2), the bridging device being controllable by means of a fluid.