The latest train hymns continue:
"Kumbaya, Mother Thomas, Kumbaya..."
which is, of course, a spoof of
"Kumbaya, Mother Goddess, Kumbaya..."
So I'm not quite sure what imagry is going through Arthur's head -- The Goddess in her manifold train aspects (how Marija Gimbutas), or if Arthur is imagining Thomas the Tank Engine running a shelter for the poor in Calcutta.