John Brown Frederikstadt 1885

gday all, i am trying to find information on my great grandfather details below: name: John Brown (doesn't quite sound Norwegian) Birth: 5th August 1885, Fredrikstadt, Norway Landed in Australia: 1906 on the Barque Hermes in Rockhampton, Queensland from Bristol England Naturalised: 14th September 1915 Enlisted WW1: September 1915 Died: 9th October 1917, Belgium his children born in Australia: John Brown, Alfred John Brown (my father named after), Frederick Brown on his enlistment papers he has put that he served 3 years in the Navy USA all the above information is from his enlistment/naturalisation papers... many thanks for any help, really appreciate it, oh we will be over to Norway/Sweden June 2016, it would be great to find where he lived and if any living relatives....