Abstract: A horizontally elongated edge upstanding panel is provided and includes front and rear sides as well as pairs of upper and lower corner portions disposed in the same plane. The panel includes a central area which is laterally offset forwardly of the aforementioned plane and the forward facing side of the panel includes generally planar upper and lower surfaces as well as generally planar opposite side surfaces convergent toward the central area of the panel member. The side surfaces are substantially vertically disposed while the upper surface is forward and downwardly inclined and the lower surface is forwardly and upwardly inclined. The forward displacement of the central area from the plane containing four corner portions of the panel is equal to approximately 1/10 the length of the panel and slightly less than the vertical height of the panel.

Abstract: A semi-trailer construction including forward coupling structure for universal coupling and support from a towing vehicle, a rear portion from which wheeled running gear is supported and an intermediate portion dependingly supporting supplemental wheeled running gear is provided. The supplemental wheeled running gear includes a mounting plate supported beneath the semi-trailer frame for oscillation relative thereto about a vertical axis and horizontal shifting relative to the frame along a predetermined path extending through the axis of oscillation of the mounting plate relative to the frame. The mounting plate supports a transverse axle assembly therefrom having support wheels journaled thereon and the axle assembly is disposed generally normal to the aforementioned path.