Thomas & Friends: Season 6, Episode 11

6 - 11: The World's Strongest Engine

Henry has an unfortunate accident, leading to Diesel returning to the railway. Diesel is insistent on proving that he is the strongest engine in the world, much to the trucks' amusement. They edge him on to pulling twenty trucks at once. Diesel pulls them so hard that he breaks loose, falls off the quay and lands on a barge.