a railroad wayside signal cantilever including an arm with a signal mounting apparatus that provides a degree of horizontal movement of the signal relative to the cantilever mast . the available range of locations for securing the signal on the arm is sufficiently broad to allow a single cantilever design to be used for a wide range of site - specific locations . an extendable catwalk railing is provided to accommodate movement of the signal without creating an unsafe gap between the railing and the signal .