Mitton directed 180 out of 182 episodes of the seven series made between 1984 and 2003, as well as writing the scripts once the original stories had been filmed. Mitton was able to move each engine's eyes in real time – not stop-frame animation– by using a radio control linked to a motor mounted behind them, and there was a sculpted mask that could be changed to give different facial expressions. The role of the narrator was played by Ringo Starr for the first two series in the United Kingdom and the first series in the United States. Ringo Starr was replaced by Michael Angelis in the United Kingdom and George Carlin in the United States.