The Coalbrookdale locomotive was an early steam locomotive built by Richard Trevithick. It is now heavily regarded as being the first steam locomotive ever invented.
The Coalbrookdale locomotive first appeared in The Railway Series: Surprise Packet, and in the 1979 annual. A replica appeared in Thomas and the U.K. Trip when Gachapin and Mukku were visiting several heritage railways and a Thomas & Friends Japanese documentary, Hashire! The "Thomas the Tank Engine and Friends" Steam Locomotive is Alive.
- The Coalbrookdale locomotive was mentioned on The Official Website's Twitter. 
- The spare cogs were later used to give Theo a more experimental appearance in Journey Beyond Sodor.
- Coalbrookdale Locomotive on Wikipedia