Last weekend Amy and I took the TranzAlpine train from Christchurch to Greymouth. We left on Saturday morning at 8am and returned on Sunday at 6pm. There had been fresh snow on Arthur's Pass on Friday night, so we stomped around and threw snowballs on Saturday morning.
The railway line goes through the Otira Tunnel, which at the time of its completion (1923) was one of the longest railway tunnels in the world. It's just over 8.5 km long and takes 12 to 15 minutes to traverse, depending on whether you're going downhill or uphill. There are 19 tunnels in total between Christchurch and Greymouth.
Greymouth was stormy and cold when we got there. Our host Sandie from Jivana picked us up from the train station and had hot mushroom soup ready for us! We enjoyed our stay in Greymouth but probably would have liked another full day there.
On the way back, we again had lovely clear weather over the Southern Alps. On the return trip we spent some time on the open air viewing platform ("fully air-conditioned!" as they say, and it was cold) and got some better pictures. It's really hard to take pictures from inside a moving train, because of the unwanted reflections.
Train travel really is a civilised way to travel. It takes about as much time as a car for the same trip, and you don't have to worry about driving, road conditions (which were treacherous that day), or other drivers. You get to sit back and relax, and enjoy the scenery. Some of it is scenery you can't even see from a car, because in this case the railway takes a different route from any roads. There is food available on board, at reasonable prices. The important thing is that the speed is still "human-scale"—the distance and terrain is respected and not made to vanish as it does when traveling by air.
I have a few pictures from the trip online.