Just for completeness there are more spiral tunnels on the Gotthard route than have been mentioned so far.
In the Wassen area there are the Pfaffensprung (spiral-the track loops over itself), Wattinger (semi-circle full 180 degree reversal of direction) and Leggistein (semi-circle) Tunnels.
In the Dazio Grande there are the Freggio (spiral) and Prato (spiral) Tunnels,
In the Biaschina, perhaps the most spectacular of all, the Pianotondo (spiral) and Travi (spiral) Tunnels.
There are quite a few spiral tunnels in the French and Italian Alps, although, typically, I can't put my hands on the book I want to check in (Railways through the mountains of Europe in case anyone has a copy to hand). I think the Flam line in Norway has several loops, both open and in tunnel.
Hopethe above is of use
