Calm Down Caitlin by Postman Pat, Dennis & Gnasher and Rastamouse writer Davey Moore, aired today on Channel 5 milkshake! in the UK.
The episode introduced viewers to Caitlin the Mainland Engine who couldn't contain her excitement to be working on the Island of Sodor, despite it being night time.
O'Mara, who graduated from LAMDA, has largely worked in the theatre industry acting in plays such as Macbeth, The Way of the World, Far from the Madding Crowd and Mrs. Warren's Profession.
She has had a limited time in television with roles in the BBC's Doctors, ITV's The History of Mr. Polly and of course, Thomas & Friends.
Unlike O'Mara, Forbes has had an extensive career participating in theatre shows alongside the Royal Shakespeare Company with King Lear, Hamlet and Romeo & Juliet to name but a few.
Playing parts in two films, Forbes has also lent his voice to many BBC Radio productions and has been on the small screen in The Bill, Casualty, Foyle's War and more recently in Charlie Brooker's Black Mirror on Channel 4.
LEARN MORE ABOUT THE TWO VOICE ARTISTS' WORK ON THEIR ONLINE CV'S