A door operating mechanism for operating longitudinal doors of a railroad hopper car. The mechanism includes operating members that are coupled to ends of the doors. These operating members are each actuated by a separate actuating device that is coupled to a top surface of a sill of the hopper car. Door supports have one end coupled to a door and an opposite end coupled for rotation to an actuating device. When a power cylinder coupled to the operating member is activated, the actuating devices are rotated. This rotation causes the door supports to shift in opposite directions and to open the longitudinal doors.