A multiple purpose freighter, having cargo holds, in which there are bags to contain oil or the like. Each of the bags is joined with an in-outlet of oil. While the bag contains oil, there is a watermat between the bags and the hold's wall and bottom. Valves are provided at the hold's bottom to connect the two sides of the hold's wall and bottom, and are closed when the bags are being damaged. The oil could be removed from the bag through the in-outlet by pressing water into the hold with the valve. The invention provides a new method to overcome the problems of unsafety, environmental pollution, unitary function of transport and so on.