A containerized portable shelter which is small and light enough for helicopter transport but which can also travel through container channels and has increased expandability of the floorspace is provided. It has a fraction (e.g. one-half) the standard ISO width, so that a plurality of modular units can be joined to form a standard ISO container. Two or more modular units can be joined side-by-side and/or end-to-end to form a compound shipping container preferably having ISO freight container characteristics.