Thomas & Friends: Season 5, Episode 4

5 - 4: Lady Hatt's Birthday Party

On his way to his wife's birthday, the Fat Controller's car becomes stuck in a pothole. He hitches a lift in Caroline, who breaks down, and then George, who loses control and crashes into a muddy pond. Thomas, luckily, is nearby and the Fat Controller is forced to act as his "relief" fireman to reach the party in time.