Abstract: A simultaneous twinsheet thermoforming system having a carousel rack to simultaneously move two sheets of thermoplastic together through a heating station and a forming station. The two thermoplastic sheets are vertically disposed on upper and lower tiers of the rack. The single heating station includes vertically disposed upper and lower ovens, which both sheets pass through simultaneously. The ovens each include upper and lower heating platens, the lower platens being movable to accommodate for sagging thermoplastic. The forming station includes upper and lower vacuum molds that are movable from an open position to a closed position. In the open position, the two sheets are moved in between the mold faces. The molds are driven together to contact the sheets and simultaneously form the two sheets to the two molds. At least one of the two molds is further moved to establish contact between at least portions of the two sheets, thus fusing them together.