I really love Snowpiercer series. I think the Tallie did board from all the trains but were forced to move to the tail section. I'm not sure though.

Thankfully its available on netflix in my country and the season 3 is out too. Each episode comes out every week. I'm waiting for all the episodes to be out before I start watching it. Can't be waiting week by week. I really hope Melanie survive in season 3, her character has come to grow on me.