I saw some amazing work done in Melbourne on the SkyRail between Caulfield and Oakleigh. They kept the surface lines operational while the built the elevated rail up above. Still had closures but probably not as much there would have been if they were not innovative. I still think there will be significant closures for LGCFR. The thought has crossed my mind in that they might go for block closures and go all out for some sections. I also hope they aim to finish before 2031 (the present announced completion date).
Interesting blog article by Daniel Bowen: Building skyrail while the trains keep running
