Murdoch is Sodor's orange tender engine.
Murdoch is a mighty engine with 10 drive wheels. He was brought to the island to help with the heavy workload and pull freight on the mainline. As shy as he is strong, Murdoch can often be found seeking peace and quiet. 
Murdoch was brought to relieve the engines of their heavy workloads. He was big and strong, so the other engines were eager to learn more about him. Murdoch, however, disliked the noise of their chatter and got cross at Salty and Harvey when they inquired about his past exploits. The next day, Murdoch finally had a chance to pull a train in the quiet countryside, but his journey was interrupted by a flock of stray sheep. Murdoch had to wait with the noisy sheep until Toby could bring the farmer to lead them away. That night, Murdoch found Salty's and Harvey's company a relief.
On one windy autumn day, a large red carpet landed on the back of Murdoch's goods train, unbeknownst to Murdoch. Percy briefly chased after it, until the heavy winds blew it away again.
Emily once needed Murdoch's help when she became stranded in the mud and near the end Emily asked him which track should she take; Murdoch told Emily that the tracks on Gordon's Hill were being cleared and told her to take the valley route instead.
In spite of his size, Murdoch is gentle and shy. He prefers peace and quiet, also he can work very hard with any job he has, and his favourite hobby is to have a quiet run through the countryside.
Murdoch is based on a BR standard class 9F goods engine, the last make of steam engines to be built for British Railways, in 1960. That is, before "Tornado" was built in 2008.
- Bob Golding (UK; coming soon)
- Tom Kenny (US; coming soon)
- In the UK, Murdoch gains a Scottish accent in the twelfth series.
- He is the first engine in the to have Television series Smoke Deflectors.
- The TOMY Road & Rail System merchandising used to spell Murdoch name as "Murdock."