An electro-mechanical orientation system for conveyed articles having a distinguishable top and bottom such as a rail tie plate or the like is disclosed comprising a sensor frame having a transverse pivot axis, a plurality of elongate sensor fingers pivotable about that axis and subject to a biasing force, a plurality of notched beam interceptors, one mounted to each sensor finger, a corresponding plurality of opto switches and a logic circuit, whereby the frame is oriented in relation to a conveyor surface so that the sensor fingers intercept and are triggered by the conveyed article. The pattern of triggered sensor fingers is transmitted through the beam interceptors and opto switches to the logic means, from where it may be used to trigger a conveyed article reorientation device.