Iron 'Arry, along with his brother Iron Bert, is a diesel engine that works down in the scrap yards and smelters sheds. As with most diesel engines, 'Arry feels that diesel engines are much superior to steam engines and enjoys breaking them down when he gets the chance. Because of his grim job of melting down engines, 'Arry is sometimes referred to as the "Grim Messenger of Doom" by the other engines.