I've decided to take a weeks holiday in May, flying into Oslo. The reason is that I would like to do a railway tour and from my research it seems there are 5 railway journeys to do. They are The Bergen Line, including the Flam Railway, The Dovre LIne, The Rauma Line and the Arctic Nordland Line. I think I should purchase an interrail pass if I'm going to do all these, is that the right decision? Also I'm aware that the Bergen, Dovre and Rauma all start in Oslo, which means I will need to keep returning to the capital to take the next train. Also it means doing the journey twice. Is it feasible to do all these journeys in 7days? Would appreciate any help and advice, air tickets booked but nothing else at present. Oh, also apart from booking my first nights accommodation before leaving, would I be ok to get a bed for the night easily for the other 6nights?