A dump truck having a body (11, 111) adapted to be fitted thereto, the body (11, 111) being capable of tipping relative to the truck, the truck comprising at least two axles, the body (11, 111) comprising; two side surfaces interconnected by a longitudinal surface keeping the side surfaces in spaced apart relation; the longitudinal surface and the side surface defining a cavity for receiving a payload comprising earthen material; the longitudinal surface is in the form of a contoured panel, formed from a plurality of plates (31, 31a), incorporates one or more curved sections, and provides a floor section and a front wall section; one or more of the plates are curved, such that they take the form of a portion of a side of a cone or bicone, and cooperate with adjacent plates to provide the curved sections; plates providing the bottom of the front wall section are common with the plates providing the forward end of the floor section such that the transition between floor section and front wall section is seamless; the side surfaces flare outwardly from the front wall section to the rear of the body (11, 111); the front wall section is divided into three sections across the width of the body (11, 111): a right, middle and left section, the right and left sections are angled rearward; the transition of the left and right front wall sections with the left and right side of the bottom section forms a conical shape; such that the payload is self-centering as the body is loaded, such that once loaded, the load exerted on each axle is substantially independent of the volume of payload received in the cavity such that the load is evenly distributed across tyres of the vehicle, and such that the variation in payload distribution on each of the at least two axles is less than 5% between a first payload having a first volume or density and a second payload having a second volume or density, neither payload resulting in the gross vehicle weight limit being exceeded, the body (11, 111) comprising a canopy (41, 141) to protect the cabin during loading of the body (11, 111), characterised in that the canopy (41, 141) is formed from a plurality of plates, one or more of which are curved, wherein the canopy (41, 141) transitions into the front wall section of the contoured panel with curves which are reversed to the curve of the front wall section transition into the floor, wherein a surface of the canopy is angled rearwardly toward a central area of the body such that a central portion of the canopy is lower than a front edge of the canopy, and wherein the sides of the canopy are angled downwardly toward the centre of the canopy such that the central portion of the canopy is lower than the sides of the canopy. two side surfaces interconnected by a longitudinal surface keeping the side surfaces in spaced apart relation; the longitudinal surface and the side surface defining a cavity for receiving a payload comprising earthen material; the longitudinal surface is in the form of a contoured panel, formed from a plurality of plates (31, 31a), incorporates one or more curved sections, and provides a floor section and a front wall section; one or more of the plates are curved, such that they take the form of a portion of a side of a cone or bicone, and cooperate with adjacent plates to provide the curved sections; plates providing the bottom of the front wall section are common with the plates providing the forward end of the floor section such that the transition between floor section and front wall section is seamless; the side surfaces flare outwardly from the front wall section to the rear of the body (11, 111); the front wall section is divided into three sections across the width of the body (11, 111): a right, middle and left section, the right and left sections are angled rearward; the transition of the left and right front wall sections with the left and right side of the bottom section forms a conical shape; such that the payload is self-centering as the body is loaded, such that once loaded, the load exerted on each axle is substantially independent of the volume of payload received in the cavity such that the load is evenly distributed across tyres of the vehicle, and such that the variation in payload distribution on each of the at least two axles is less than 5% between a first payload having a first volume or density and a second payload having a second volume or density, neither payload resulting in the gross vehicle weight limit being exceeded, the body (11, 111) comprising a canopy (41, 141) to protect the cabin during loading of the body (11, 111), characterised in that the canopy (41, 141) is formed from a plurality of plates, one or more of which are curved, wherein the canopy (41, 141) transitions into the front wall section of the contoured panel with curves which are reversed to the curve of the front wall section transition into the floor, wherein a surface of the canopy is angled rearwardly toward a central area of the body such that a central portion of the canopy is lower than a front edge of the canopy, and wherein the sides of the canopy are angled downwardly toward the centre of the canopy such that the central portion of the canopy is lower than the sides of the canopy.