What is the main conflict in Station by Eamon Grennan?

In "Station," the speaker and his young son are at the Hudson Valley train station in upstate New York. The boy's parents are divorced, and he is about to leave his father and go to visit his mother. The poem describes the scene at the train station and the thoughts of the boy's father, who knows this is a turning point in his relationship with his son; not only is the boy going away, he is also about to enter adolescence. This is a stage, a "station," along the boy's path to adulthood, and the father knows that things will never again be the same between them. He also realizes that he cannot find the right words to say to his son on this occasion.