The first and original group was 847, 848, 1828, and 1829. The second group was in July which was 849, 850, 1830, 1831. This third group is 851, 852, 1832 and 1833. Unless they somehow didn’t number them in consecutive order, this is what the group numbers are. For each new group, just keep adding one to each digit and you’ll know the coach numbers that arrive. Although the third group, I saw last Friday aside track 1 mainline.