Get a look on the track topology on openrailwaymap:
https://www.openrailwaymap.org/?style=gauge&lat=62.774837258...
replies(4):
https://www.openrailwaymap.org/?style=gauge&lat=62.774837258...
Probably more to do with the fact that the first train in Spain was build in Cuba
bast copy of the Subercase report I could find: [1] https://www.agrupament.cat/documents/Informe%20Subercase.pdf