Alfred is carrying lifejackets over the dock to the Wilhelm Gustloff. As he works he imagines how he would react if the U.S. Army bombed him. He imagines he would fight back impressively.
Alfred is delusional. Although at no point has he demonstrated any physical strength or any courage, he nonetheless believes that, in the right situation, he would prove himself a hero.
Alfred prides himself on his self-perceived powers of observation, which he thinks are especially important considering Hitler’s love of order and documentation. Alfred has invented a song to help him remember “the Reich’s racial, social, and political enemies.” It bothers the other sailors when he sings it, but Alfred believes they are merely “jealous of [his] archival facilities.”
Alfred’s song soothes him like a lullaby or nursery rhyme would. The act of repeating it is a kind of meditation, which calms him, as does the content itself. The song reaffirms Alfred’s self-perceived racial superiority as a member of the German “master race.”