From the article it sounds like the fixed platforms themselves were built out of spec.
From the article it sounds like the fixed platforms themselves were built out of spec.
This - sometimes - simply doesn't happen, I can remember at least two similar cases, a "big" one in France:
https://www.cnet.com/news/engineers-blamed-as-france-orders-...
And a "smaller" in Italy (no English source I can find, sorry):
https://www.ferrovieabbandonate.it/linea_dismessa.php?id=226
https://www.comune.roma.it/PCR/resources/cms/documents/Incon...
basically the tunnel didn't allow enough clearance for a double track in certain points, so a single track was placed (temporarily, for Itala 90 world championship, some 30 years ago, the tunnel was used - with single track - for a few days and then closed, it will probably be reopened in 2022).
https://en.wikipedia.org/wiki/Structure_gauge now go procrastinate.