Ravenglass and Eskdale Railway's Northern Rock
Jock is the newest steam engine on the Arlesdale Railway, and the strongest.
After Rex's steam-pipe began leaking one day and Frank had to take his train, the Small Controller began thinking they needed another engine and so he arranged for Jock to be built. When Jock first came out for testing he was still unnamed. Jock's paint colour reminded Douglas of his days on the Highland Railway and suggested the name "Jock" for the new engine. The Small Controller and Jock liked the name so it stuck. Later, he pulled a doubleheader with Mike.
Jock was very cocky when he was first built, as a result of being rather strong, but soon learned the value of teamwork when Mike's injector failed and he had to pull Mike and his train single-handed.
Jock is painted in a Highland Railway chartreuse yellow livery with red lining. He has a brass dome, red nameplates with yellow writing mounted each side of his boiler and "Arlesdale" written on his tender in yellow.
- Season 1 - Oliver and the Snowstorm (cameo)
- Season 2 - Quack!, Miniature Engines, and Mike and James (cameo)
- Season 3 - Superior Designs
- Season 4 - Duck and the Coaches (cameo) and The Wrong Sort of Coal
- Season 5 - Bert Tries His Best
The Adventures on Sodor
- Thomas and the Storm (cameo)
Adventures on Rails
The New Adventures on Rails
- Volume one - Ryan and the Boats (does not speak).
- Volume three - The Re-opening, The Trouble with Ballast Trucks.
- Season 1 - Frank and the Rolling Thing