Articulated connectors are attached to and extend from center sills of adjacent car units of a multi-unit railroad freight car, connecting the car units to each other and to a shared truck. The center sill of each of the car units includes a top member that is of increased thickness at the outer end of the center sill. A weld extending along a shoulder that extends around the main body of s portion of the articulated connector attaches the articulated connector portion to the outer end of the center sill with ample strength to carry draft and buff train loads as well as the weight of the car unit and its lading, without the need for weld joints inside the center sill.