Balance lever coupling

By exchanging the tension and compression devices, the standard screw coupling used on standard gauge railroads became the central buffer coupling with screw coupling on the side connected to a balance lever[3] The balance lever coupling has a movable balance lever mounted transversely behind the buffer, to which a draw hook is attached on the left side of the center buffer and an eye with a screw coupling on the right side.

The turnbuckle-style arrangement pulls the vehicles together so that a preload is applied to the center buffers of the couplers, providing a smooth, jerk-free ride.

The balance levers may be located in front of or behind the buffer beams, in which case the hook and eye for holding the screw coupling pass through recesses in the buffer beam.

In the case of simple designs, the screw is partly replaced by a triangular isosceles chain link.

On the Rhaetian Railway, the roller bogies (roller carriages) are equipped with normal couplings; if necessary, flat wagons can be lined up as barrier vehicles in between.