Kaplan born 1876 in Austria to railroad worker family. Graduated high school Vienna 1895. Studied mechanical engineering at Technical University Vienna specializing in diesel engines. Drafted military 1900-1901 in Pula. Worked on motors in Vienna then researched civil engineering in Brno. Appointed head of water turbines institute 1913. Published Kaplan turbine 1912 with four patents 1912-1913. First 26 kW Kaplan turbine built 1918 in Lower Austria used until 1955. Kaplan turbines adopted worldwide as major water turbine type. Received honorary doctorates 1926 and 1934. Died 1934 of stroke in Austria. Featured on 1961 1000 schilling banknote. Honored on Austrian stamps 1936 and 1976.