The aims of the project were to improve the internal and surface qualities of the billets, and to increase the production capacity by 20 percent. This was achieved by installing a new machine head, which included DiaMold molds and a retractable DynaFlex oscillator, as well as by optimizing the secondary cooling. The new plant has a modular design, and was pre-assembled to keep installation and downtimes short.The five-strand continuous billet caster owned by ESF in Riesa was installed in 1994 by a third-party supplier. It had an annual production capacity of around one million metric tons of billets with square cross-sections of 130×130, 140×140 and 160×160 millimeters. The plant has a machine radius of six meters and reaches casting speeds of up to 3.8 meters per minute. It casts low and medium-carbon steels, which are further processed in a wire rod mill in the Riesa plant. Retractable DynaFlex mold oscillators were installed to increase capacity. This solution enables the mold on a strand to be exchanged without interrupting the casting process, increasing both the productivity and the flexibility of the casting plant. All mechanical connections are released hydraulically at the touch of a button. The complete machine head, including mold and oscillator, is moved from the casting position to the maintenance position on a mobile platform. The time between stopping and restarting the strand to change a mold is between just 15 and 20 minutes.