Abstract: Machine (10-110) to restore railway road beds with a continuous endless-conveyor riddle, the machine (10-110) comprising a frame (11) on trolleys (12-13), an excavator chain means (19), riddle means (25-125-47) with at least one continuous endless-conveyor riddle (25-126), discharge means (30), means (36-38) to distribute restoration material, and alignment grippers (39-40), in which machine (10-110) the continuous endless-conveyor riddle (25-126) sorts the material with its upper segment alone.