Securing Nested Tunnels Optimization with Access Router Option

Disclosed is an improved railroad freight car having means for minimizing sway of the car during movement over rails. The car has a side bearing walled structure between each wheel truck side frame and the car floor structure. Each walled structure defines an enclosed chamber of variable volume containing a fluid. The car has a conduit communicating with the enclosed chamber and a reservoir tank containing fluid under superatmospheric pressure. The conduit transports fluid from the chamber to the tank upon reduction in volume of the enclosed chamber due to increased pressure on the chamber through swaying of the car body to that side, and transports fluid from the tank to the chamber upon increase of the chamber volume due to decreased pressure on the chamber through swaying of the car body to the other side.