Mini electric train for tunnel construction - photos and video

Mini electric train for tunnel construction.

https://diqn32j8nouaz.cloudfront.net...1_fullsize.jpg

https://diqn32j8nouaz.cloudfront.net...n_fullsize.jpg

4:38 video:
https://www.youtube.com/watch?v=bgeOR6X7lmQ


Previously:

https://www.homemadetools.net/forum/...498#post181965
https://www.homemadetools.net/forum/...224#post180709
https://www.homemadetools.net/forum/...541#post173999

at about 4 mins in, the engineer demonstrates the equipment for adjusting the elevation of the track. I liked that. At about 0.47, he tells us that the gauge is narrower than the standard width, I think 27cm or it could be 57. Anybody know?