The roof is a circular array of four curved-edge hypar saddles that intersect at the center point, resulting in an eight-sided groined vault. The plan is radially symmetric with a maximum diameter of 139 feet. Groins spanning 106 feet between supports. Trimmed at the perimeter to form a canted parabolic overhang, the shell simultaneously rises up and out at each undulation. The force paths from these overhangs act in the opposite direction from forces along the arched groin, reducing outward thrust.