Christians Ostenfeld

Christen Ostenfeld (born November 27, 1900 , † February 19, 1976 ) was a Danish civil engineer, founder of COWI

Ostenfeld was the son of the professor of civil engineering Asger Ostenfeld . He graduated from the Technical University of Denmark in 1924. He then gained six years of experience abroad in France and Switzerland, where he continued his studies. In Switzerland he was at EMPA, then at the French engineering company Geleff and then at the French branch of the Danish engineering company Christiani and Nielsen. In 1930 he returned to Copenhagen, where he did his doctorate and founded his own engineering office. Notable buildings were the reconstruction of the National Scala in 1931 using reinforced concrete, the Aggersund Bridge over the Limfjord (inaugurated in 1942) and the KB Hallen in 1938. During World War II he played a leading role in the Danish resistance (treasurer of the Danish Liberation Council). After the war he relied on prestressed concrete and contacted Eugène Freyssinet , whose methods he adapted, among other things, to the colder climate in Denmark. In 1948 he developed a prestressed concrete silo based on the Ostenfeld system, which was a great success. In 1946 he took on Wriborg W. Jønson as a partner. In the aegis of Ostenfeld was the expansion into bridge construction with the prestressed concrete suspension bridge in Uittamo in Finland (1960) and Ny Lillebæltsbro, built between 1965 and 1970 . In 1972 he retired.

Ostenfeld wrote a book about French civil engineers. He was impressed by Freyssinet, his willingness to take risks and his intuitive approach and worked with him as early as 1941 on a (unrealized) bridge to Fanø . Ostenfeld was instrumental in spreading the knowledge of prestressed concrete in Denmark, as was the Belgian Gustave Magnel , who, unlike Freyssinet, was a good communicator and gave lectures in Denmark in 1948. The German (especially Emil Mörsch ) and Swedish writings and design regulations influenced Ostenfeld (whereby the Swedish practice was strongly influenced by the German), but they were sometimes too complicated for him. In 1949 the new Danish standard was issued, which also dealt with prestressed concrete. The first application in Denmark came from prestressed concrete beams from a Swedish company (Strängbeton), which was producing in Denmark from 1947. The first major application of prestressed concrete in a building structure was made by Ostenfeld in the roof of department store 47 in Copenhagen's free port (1948/48). Other early prestressed concrete structures from Ostenfeld's engineering office were smaller bridges with prestressed concrete using the Freyssinet method and the grandstand of the stadium in Esbjerg .

The later COWI board member, Klaus Ostenfeld, is his nephew.

literature

• Niels Gimsing, Klaus Ostenfeld : Eminent structural engineer: Dr. Techn. Christen Ostenfeld (1900–1976), Structural Engineering International, Volume 3, 2012, pp. 424–428
• Jorgen Burchardt: From invention to production: The introduction of prestressed concrete, in: Wouters u. a. (Ed.), Building Knowledge, Construction Histories, 6th ICCH, Brussels, CRC / Taylor and Francis 2018, Volume 1, p. 413

Individual evidence

1. ↑ East field Franske broingeniorer og videnskabsmand, Lyngby: Polyteknisk Forlag 1975