Gabriella Flori

Span Systems International, Inc. (New York, NY) has been a world leader in the field of tension membrane structures since 1965, and currently expand its market presence into overseas from its Europe Office.

To get an overview of the broad variety of fabric structure projects that we have completed, please visit our web-site www.spansystems.info. Our work starts by taking the concept of the Owner or Architect, and converting it into a sound structural design, in accordance with all applicable specifications (ASTM, ASCE, BS, or other, local codes). After the Building Permit has been issued, we manufacture the components (fabric membranes, cables, steel and aluminum members, etc.) and erect the structure on foundations built by others to our design.

Our web-site also describes our Spandome system, one of the world's most successful fabric structures system. Although very large areas can be covered with these lightweight structures, the clear span of Spandomes is still limited to about 250 meters, which is the span limit of all known technologies. The reason for this limit is that nature's unsymmetrical, random loads (snow, wind) cause both compression and bending stresses in the structure's supports. With increasing clear spans the increases in compression remain linear, but the bending moments increase exponentially, and that makes dome structures with more than 250 m spans too heavy to carry their own weight. The only way to eliminate bending moments would be to somehow force nature to distribute its loads evenly and symmetrically. Nobody has been able to do that.

But this is exactly what our latest invention, the Spantheon system, enables us to do. For a detailed description of how it is done, please see our other web-site www.spantheon.com, or International Patent WO 2006/136867 "Roof Arches Without Bending Moments". The first Spantheon will have a 500 m clear span, (covering 120,000 m2), but giant domes of much greater spans can be built, paid for by the savings in what they cover. Under such transparent domes, new evergreen cities can be built for those societies, which will be displaced by global climate change, rising sea-levels, desertification, heavy air-pollution and energy shortage.

We see a great future for our work, and you can be the part of realizing that future.