A dewatering unit in the form of a railcar having bogies thereon to move the unit on rail tracks. The dewatering unit has first and second ends, first and second sides, and a bottom that bound and define an interior chamber. A conveyor is provided in the interior chamber and screens are located in the bottom and first and second sides. A grizzly is located below an opening in the unit's top and above the conveyor. Stabilizing assemblies are deployed to contact the ground and lift some weight off of the bogies prior to loading. A solid material/liquid mixture is dropped through the opening and onto the grizzly which partially fractures the solid material. Further fracturing is undertaken by conveyor drag bars and crushers located adjacent the conveyor. Liquid drains from the unit through the screens. The dewatered solid material is lifted out of the unit by the conveyor.