Early in his career, he received two Norwegian sport awards shared with his brother Frank.

Towards the end of his career in 1990, he was the inaugural recipient of the Thomas Keller Medal, the highest honour in rowing.

[4] He then changed boats and competed at the 1974 World Rowing Championships in Lucerne, Switzerland, in double sculls with his brother Frank; they won a silver medal beaten by a team from East Germany.

[4] In 1976, the brothers won a gold medal at the Montreal Olympic Games in the same boat class.

Alf Hansen continued his career and teamed up with Rolf Thorsen in the double sculls.

[2] At the 1989 World Rowing Championships in Bled, Hansen was part of a newly-composed quad scull team; they came sixth.