dear Mr. Rosenthal:
A few years ago, Clouth developed and successsfully tested a belt with an ST8200 rating for the Henderson 2000 project in Colorafo. Before producing the belt, however, they determined that a lighter construction woulod suffice and used that rating instead.
You can get information on that direct from Clouth (or ContiTech).
Most of the large belt manufacturers are willing to develop higher strength belts, if there is a need. If you require current status reports on what is posssible, contact companies such as Continental/Clouth (Germany) and Goodyear (USA).
Hope this helps.
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