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.

Provided are a railroad vehicle that makes it possible to maintain the air tightness of a door and a plug door for a railroad vehicle. A second rail is provided parallel to a first rail in the longitudinal direction of a vehicle body above the leading edge side (door side) of a plug rail. The second rail supports the leading edge side of the plug rail. As a result, both edges of the plug rail are supported by the first rail and the second rail. Dangling of the leading edge side of the plug rail is thus prevented even when the plug distance (the distance that the door moves in the vehicle body width direction) is long. In this way, it is possible to block the doorway without leaving a gap using the door and to maintain the air tightness of the door.