Abstract: A vehicle is provided with a plurality of refuse collection units one of which is compactor unit mounted transversely across the vehicle. The vehicular mounted waste compactor includes a hollow body having opposed open ends each having an intake opening for receiving waste to be compacted. Divider walls within the interior the hollow body divide the interior into a receiving chamber and a compaction chamber with a passageway communicating therebetween. To reduce the length of compaction stroke and the space needed for the ram, it includes a sliding cover wall movable back and forth for selectively closing and opening the passageway. One end of the hollow body has a door against which the ram compresses the waste material. When opened, the compressed material is discharged in the direction of ram travel. To reduce the stroke needed for compaction and the space needed for hydraulic cylinders to move the ram, the cylinders are mounted diagonally to each other and to the direction of ram travel.