An apparatus for storing or transporting flowable materials or other materials, such as diesel fuel, includes a container and a support. The container is supported by the support. The support sits on or is mounted across an upper part of an open top railway wagon or open top truck or truck trailer used for transporting bulk commodities (such as coal or iron ore). The apparatus is movable between an expanded configuration in which the container is expandable into a lower part of the open top railway wagon or open top truck or truck trailer used for transporting bulk commodities, and a collapsed configuration in which the container is collapsible to the support. In use, a railway wagon is filled with coal or other bulk commodities and the apparatus is placed on top of the railway wagon in the collapsed configuration. At the port, the coal is emptied from the railway wagon and the container of the apparatus is filled with fuel. The support supports the apparatus on the railway wagon and the container extends into the railway wagon. The fuel may then be transported back to the mine, where the apparatus is removed from the railway wagon and the container decanted. The railway wagon is again filled with coal or other bulk commodities and the apparatus is placed on top of the railway wagon in the collapsed configuration and the cycle continues to meet the fuel requirements of the relevant mine.