A tethermast and frag wall includes a fabric device having a fill volume fillable with a fill material on a flexible or compliant mast system. The fill volume may be a chambered curtain. The tethermast and frag wall is self supporting, easily deployed, and may be used in connection with a structure or may be deployed stand-alone. A tether system for an air beam structure utilizing a flexible tethermast, an external frag wall or frag curtain, soft couplings, air beam slings, or combinations thereof to reduce the effects of pressure waves, such as blast waves, onto and into an air beam structure and any inhabitants.