Frank is a Diesel who works on the Arlesdale railway.
Frank arrived on the Island of Sodor in 1975 the same year he was built. He was a very grumpy diesel always doing maintenance around the railway. He crashed at the back of the shed not long before Jock was built he was later doing some maintenance near the shed, when he passed the engines he said he was overworked the Bert said that he only worked 5 hours a day and that they however worked 10 hours a day. he was then usually just seen doing classical maintenance around the railway.
- Toad the Lucky Brake Van (cameo)
- Oliver's Tiny Tale (does not speak, not named)