I soon had booked my ticket (soft seat for 55000 vnd) for 8:30 a.m the following morning and i went back to the hostel and played pool with the hosts for a little longer before retiring for an early night.
This morning I walked the 20 to 30 minutes to the train station and was there about 20 minutes early . I checked I have the right ticket before I got on the train. It pays to do this with a with a few people . On the train I met a nice family of vietnamese people who had a young child with them I found a place on the train that I could walk to, and open the window as most windows were absolutely filthy . With the window open I was able to try and get some good photos of the mountain pass (Hai Van Pass) as we went over it is.
Apparently a very popular scenic route. Its a 3.5 hour trip, but the train stopped a few tines to give priority to others coming the other way.