en Cuevana 3. Two Furnaces for Udarnik Josip Trojko follows the disassembling of the famous Siemens-Martin furnace, which once stood at the heart of the huge Yugoslavian iron industry. As we watch the old making way for the new, we hear off-camera archive recordings of political speeches, full of enthusiasm and ideological optimism, from the period when the old furnace was in operation.