Need a Swedish sailing term "dunkie"

Hello, I am not a sailor but I am writing a bio for a man who spend ten years sailing on dry bulk carriers in the 1950s. At the time, he was living in Germany and sailed on both German and Swedish ships. In 1954, he sailed as a bosun with a Swedish ship called[I] Windar[/I]. He became very good friends with the head stoker. He uses a term to refer to his friend’s position that, to me, sounds like [I]dunkie[/I]. It means ‘someone who is the head of the stokers’. Is anyone familiar with this term and know its proper spelling? I can’t find a reference to it anywhere I have tried searching. Thanks!