Abstract: A generally horizontal load bed is provided including a longitudinal marginal edge and a plurality of cantilever support arms are spaced along the marginal edge of the support bed and pivotally supported therefrom at one set of corresponding ends of the arms for angular displacement of the arms relative to said load bed about upstanding axes for swinging between extended positions with the other set of corresponding ends of the arms projecting outwardly from the load bed marginal edge and folded positions with the arms generally paralleling the load bed marginal edge. An elongated extension panel assembly is provided and parallels the load bed marginal edge and overlies and is supported from the support arms.

Abstract: A hydraulically operated tailgate associated with a low bed, semi-trailer vehicle has a pivoted extension that is displaceable between an extended position coplanar with the ramp surface of the tailgate and a bumper position transverse to and underlying the ramp surface. A hydraulic actuating mechanism displacing the extension to the bumper position, simultaneously locks the tailgate mechanically to the frame of the semi-trailer vehicle.