Travel time from Oslo to Hamburg in 1878

My great grandfather, Carl Olaf Carlsen and his mother Caroline Elisa Carlsen travelled from Oslo to Hamburg on 2 November 1878 on the SS St Olaf. I believe they may have then travelled on the ship Charles Dickens from Hamburg to Rockhampton, Australia on 6 November 1878. How long would it have taken to sail from Oslo to Hamburg? If this journey took longer than 4 days it would seem then would not have been able to sail on the Charles Dickens. Any information would be greatly appreciated. Lisa