Career
He was mayor of Stolberg for 10 years. Kaltenborn moved to Stolberg in 1946 and began working for the Social Democratic Party of Germany. In 1979 Kaltenborn was elected as mayor of Stolberg and succeeded Bernhard Kuckelkorn. Kaltenborn took care of restoring the ancient part of the city.
In 1989 he lost the position as mayor to Wolfgang Hennig.
Kaltenborn died on March 29, 1999.