A trailer for a dumping vehicle, the trailer comprising: a front end, where the front end is curved; a rear end, where the rear end is narrower than the front end; a bottom floor extending between the front end and the rear end; and a pair of opposed sidewalls extending between the front end and the rear end. The sidewalls may be taller at the front end than at the rear end, may arch uniformly from the front end to the rear end, and may arch uniformly from the top to the bottom. The trailer may further comprise a top rail with an oval cross section.