Chuggington (2008)

Season 1: Episode 5

Wilson and Brewster are sent to get stone from the mountain quarry. Brewster is in a hurry to get the job done, so that he can get back and practise some new moves in the training yard with Koko. For once he doesn't slow things down by asking questions, and he doesn't hear Dunbar warning them to be extra careful on the way back, as going downhill with a heavy load is harder.