'Feather I' was a British operation by the Special Operations Executive to halt production at the Orkla pyrites mines by destroying the machinery in the lift shaft or, should this prove impossible, attacking the rail line between Orkanger and Thamshavn (10 October/17 November 1943).
The Norwegian party (P. Deinboll, O. Nilssen, A. Wisløff, L. Brønn, T. Bjørnaas, P. Skjærpe and A. Hægstad) was delivered by air, and on 30 October undertook a co-ordinated attack against the locomotives at Løkken, Thamshavn and Orkanger, which provided the motive power for the transport of the mine’s output to the coast for loading onto ships. Five locomotives were destroyed or put out of action. Another attack, on 17 November, resulted in the destruction of a rail car. One of the team was killed and one captured, and the other five eventually escaped to Sweden.