Abstract: A plurality of vertical rod assemblies restrain the movement of cargo during transport on a floor of a carrier having source of fluid which is at about atmospheric pressure while the carrier is being loaded and which is pressurized after loading, e.g., a trailer having wheels with brakes which are actuated by a pressurized air line. Each vertical rod assembly contains a rod which remains flush with the floor on which the cargo is loaded when the fluid source is not pressurized. When the fluid source is pressurized, each rod rises from openings in the floor at locations adjacent the cargo. Each rod is attached to a piston in a cylinder which moves up and down in response to the application and release of pressure.