All franchises heretofore granted by the City of Negaunee and now in operation , shall continue until the expiration of such franchises. All irrevocable public utility franchises and all renewals, extensions and amendments thereof shall be granted only by ordinance. No such ordinance shall be adopted within thirty (30) days after application for the franchise has been filed with the Council, nor until a full public hearing has been held thereon. No exclusive franchise shall ever be granted and no franchise shall be granted for a longer term than thirty (30) years. No franchise shall be transferable, directly or indirectly, except with the approval of the Council expressed by ordinance.