a storage tank having a unique geometric shape and adapted to contain a liquid or a compressed gas at pressures above atmospheric pressure . the tank can be made of special materials for low temperature applications . the weight of the tank and its contents is carried on an integral supporting structure advantageously located at the lower corners of the tank . since the tank is a single walled , pressure - type vessel , it can be utilized in the transportation of liquid natural gas without the need for a secondary liquid - tight barrier .