This structural assembly provided is of the type intended to be fixed to a longitudinal end of a rail car body including a chassis, a roof and lateral faces forming a tubular cell, in order to articulate the body to a body of another adjacent car and to transfer the load of the body to a body support bogie that is common to that other car. A lower cross-member may have a central portion and two lateral portions, the central portion being provided in order to carry a member for articulating the body to a body of another car, and each lateral portion being suitable for being supported on suspension devices for the body on a bogie.