Abstract: A cooling container vessel, comprises a vessel hull with spaced apart bulkheads which define a storage space therebetween and which includes substantially vertically arranged guide frames disposed in the space at spaced locations from the bulkheads alongside a vertically elongated manifold for the supply of cooling air. A plurality of horizontally extending double-walled cargo supporting structures are engaged with the frames and are supported thereby in a horizontal position. The double-walled cargo supporting structures are provided with an interior cavity which is supplied with cooling air by a connection carried thereby which may be engaged with a connection to the manifold and include at least one wall which has openings for the flow of cooling air into the cavity of the double-walled supporting structures and outwardly through the openings in the wall thereof.