Complex sentence: The Iron Giant, which has lost its memory, accompanies Hogarth back to the house where he lives with his widowed mother Annie, and to sustain its energy tries to eat the rails off the ties of the nearby railroad tracks.
Split into simpler sentences: The Iron Giant, which has lost its memory, accompanies Hogarth back to the house where he lives with his widowed mother Annie. The Giant tries to sustain its energy by eating off the ties of the nearby railroad tracks.