Career
Tangen chaired the trade union Norwegian Union of Building Workers from 1935, having been deputy chairman from 1933 to 1934. He chose Ludvik Buland as deputy chairman. Tangen cooperated to a certain degree with the Nazis, and visited Germany in January 1941.
He became unpopular with some, but never became popular with the authorities either.
Following the milk strike in September 1941, the Nazis took a tighter grip on society in general, usurped the Confederation of Trade Unions completely and installed Odd Fossum as new leader on 10 September. Tangen was arrested and imprisoned in Grini concentration camp from 10 September 1941 to 27 February 1942, and then at Møllergata 19 for one week.
After his release, he fled to Sweden, where he played no political role. Ludvik Buland was imprisoned and died in Germany, whereas the head of the judicial office in the Confederation, Viggo Hansteen, was executed.
After the war, in 1946, Tangen was excluded by the Congress of the Confederation of Trade Unions for collaboration.
His personal secretary, Martin Brendberg, was excluded as well. However, Tangen was acquitted of treason by Oslo City Court in 1949 as a part of the legal purge in Norway after World World War World War II The court found that his degree of cooperation was acceptable.