Arry and Bert (also known as Iron 'Arry and Iron Bert) are two diesel shunters from The Island Of Sodor.

'Arry and Bert are unquestionably devious and scheming. They feel superior to steam engines and working at the scrap yards, they enjoy the chance to break up engines or at least make their lives more difficult. Due to their grim task, they have earned a reputation on Sodor as "The Grim Messengers of Doom".

However, despite their prejudices, the diesels have cooperated with steam engines on occasions and when they are in trouble, steam engines often come to the rescue.