KINGSPORT — Kingsport City Manager Chris McCartt has made some adjustments to the responsibilities of three staff members, a restructuring of duties that he says is a step toward helping the Model City’s push toward greater economic development. In addition, the city plans to fill two more key positions by the end of September: hiring of an economic development director and a leisure services director. “Kingsport has always had a rich history in being a business-friendly city.