The Most Powerful Locomotive in the World is a German book illustrated using photographs from the television series.
Diesel thinks he is the most powerful locomotive in the world. When Henry has an accident and Diesel has to fill in for him, he gets his chance to prove it. The trucks tire of Diesel's showing off and decide to play a trick on him. They tell him to pull them all at once, but when the coupling breaks, Diesel ends up in the sea.