A short circuiting device for an electric railway system having a conductor rail for supplying electric power to drive the vehicles. The function of the device is to provide a short circuit between a track rail and the conductor rail. The short circuiting device contains a first contact element providing a face to make contact with the track rail and a contact arm that is coupled to the contact element via a jointed connection and has a contact face for making contact with the conductor rail. The jointed connection is a multi-hinged connecting facility containing two levers which are joined to each other via a knee-type joint and joined via the respective first and second connection hinges to the contact element and the contact arm. One of the levers is in the form of a closing lever and the shape and arrangement of the levers and hinged joints is such that by executing a rotational movement with the closing lever, and via this, movement of the knee-type joint about the axis of the connection hinge related to the closing lever, the contact element and the contact arm can be brought together thus making electrical contact.