Hans Kalt won the 1948 coxless pairs silver medal with his brother Josef and the 1952 bronze medal with Kurt Schmid. They started for the See-Club Zug and were coached by Kurt’s father Karl Schmid. At the 1948 Olympics at Henley there were only three boats in the final. Hans and his brother Josef had won the preliminaries and the semi-final ahead of the Australians. In the final they were beaten by the British pair of Jack Wilson and Ran Laurie, whose son, Hugh Laurie, later became a movie and television star (Dr. House). At the 1950 European Championships Hans Kalt and Schmid won the European Championship, adding a bronze medal in 1951. At the 1952 Helsinki Olympics they again advanced to the final, losing to the Americans and Belgians, winning a bronze medal. Domestically Hans Kalt was the Swiss coxless pairs champion with his brother in 1943-1945 and 1947-1948, while being second in 1946 and with Schmid in 1950 and 1953, while being second in 1952. Hans Kalt also won single sculls silver at the 1949 Swiss championships.
In 1966 Kalt was among the founding members of the Curling Club Zug and became an Honorary Member in 2000. He was also one of the founding members of the Panathlon-Club Zug and later became Honorary President. He and his brother Josef worked in the family owned printing company Kalt-Bucher Druck AG in Zug. Hans later married Thea Mathilde Jans and changed his surname to Kalt-Jans.
Switzerland