Half-round trailer and trailer body with extruded panel side walls

1. A trailer comprising:

a chassis;

a trailer body connected to the chassis, said trailer body comprising:

left and right vertical side walls connected respectively to left and right bottom rails;

a cargo space located between the left and right vertical side walls;

a curved floor comprising a left edge connected to said left bottom rail and a right edge connected to said right bottom rail;

said left and right side walls each comprising a plurality of extruded panels each comprising an inner wall and an outer wall spaced from the inner wall, wherein said inner and outer walls of each extruded panel are parallel relative to each other;

wherein an inner surface of the curved floor follows a curved path as said inner surface extends from said left edge connected to said left bottom rail to said right edge connected to said right bottom rail, such that said inner surface of said floor is located a variable distance D from an imaginary reference plane that extends through the cargo space and that is oriented perpendicular to the left and right vertical side walls, wherein said distance D is maximized when measured at a centerline of said trailer body and wherein said distance D decreases progressively from said maximized value when measured at locations closer to the left and right side walls.

2. The trailer as set forth in claim 1 , wherein said chassis comprises left and right chassis beams, said left chassis beam comprising a left saddle portion including a left curved saddle surface and said right chassis beam comprising a right saddle portion including a right curved saddle surface, wherein the left and right curved saddle surfaces are oriented inward toward a center of the cargo space and a curved outer surface of the floor is connected to the left and right curved saddle surfaces.