In a movable bridge that uses a rigid overhead rail, there is a need to transition from the catenary wire system into an overhead conductor rail at the bridge portal (the last post before the movable bridge). For example, the power supply can be done through a catenary wire system near a swing bridge. The catenary wire typically comprises messenger wire (also called catenary wire) and a contact wire where it meets the pantograph. The messenger wire is terminated at the portal, while the contact wire runs into the overhead conductor rail profile at the transition end section before it is terminated at the portal. There is a gap between the overhead conductor rail at the transition end section and the overhead conductor rail that runs across the entire span of the swing bridge. The gap is required for the swing bridge to be opened and closed. To connect the conductor rails together when the bridge is closed, there is another conductor rail section called "rotary overlap" that is equipped with a motor. When the bridge is fully closed, the motor of the rotary overlap is operated to turn it from a tilted position into the horizontal position, connecting the conductor rails at the transition end section and the bridge together to supply power.