john BROWN ?? arrival in australia

gday guys/gals, I am trying to find information on my Great Grandfather details below: name: John BROWN (doesn't sound Norwegian) birth: 5th August 1885, Fredrikstadt? Fredrickshal? landed in Australia: 1906 on the Barque HERMES in Rockhampton from Bristol. naturalised: 14th September 1915 enlisted WW1 sept 1915 killed in WW1 9th October 1917 apparently he served in the United States Navy for 3 years (on his service record) his children names: 1st born John BROWN 2nd born Alfred john BROWN 3rd born Frederick BROWN many thanks for your time I really want to trace this line back..appreciate all help steve