The largest membrane forces are carried along the intersections between the forms, called the groins. This areas are thickened by creating hidden steel reinforced “V” beams. The rest of the structure has minimal reinforcing to address creep and temperature effects, but essentially works entirely in compression. The symmetrical plan and innovative use of “V” beams allows edges free of stiffening beams, revealing the radical thickness of the 4cm (1 ½”) shell.