Down the Mine is the original 1983 test pilot of Thomas the Tank Engine and Friends before the first episode aired in the United Kingdom in 1984. Prior to 2025, the pilot was never broadcasted on television.

Produced in 1983 by Britt Allcroft, this pilot episode was seen for the first time since its creation on the official Thomas and Friends YouTube channel to mark the brand's 80th anniversary.

Thomas, a small steam-engine, loves to brag to and tease Gordon about how hard he works, but strong, powerful, self-important Gordon decides to take him on a ride he'll never forget.

Gordon gets stuck on the hill and old Edward proves that he can still be a really useful engine when he comes to Gordon's rescue.

Henry, a big green engine, doesn't want to risk paintwork being ruined by rain, so refuses to leave a tunnel he enters on a trip. But he may end up being there longer than he wants as he ends up being bricked up.

Thomas is jealous of those who get to pull coaches so jumps at the chance when Henry is sick, but ends up starting up unattached in his hurry.

Thomas is offered to switch jobs with Edward for a day since he wants to do more important things, but doesn't take the warnings seriously that freight-trucks are troublemakers.

James' brakes catch fire and his freight-trucks push him out of control, forcing Thomas to use a breakdown-train to help him and to deal with the trucks that he has gotten used to.

James' showing off results in anger and others avoiding him, but he thinks he's being put below Gordon and takes out his frustration on the freight-cars...and ends up stuck when they can't run anymore.

James wants to be able to prove he's still a good worker once he's released from the shed, but it won't be easy since the freight-trucks he's been given are determined to ruin his plans.

Gordon loves to tease James like Henry does, and to brag about how he knows the rails so well, until he and the express are put on the wrong route by mistake and James gets his wish to pull it instead.

Thomas is so impatient after waiting for Henry's train that he leaves without his guard.

Thomas always dreams of going fishing - until river-water is forced to be used to refill him.

Thomas meets Terence, a tractor, but doesn't see the point of his way of doing things. In the winter they meet again when Thomas purposely damages his snowplow then gets stuck in a drift.

Thomas strikes up a good-natured rivalry with a bus named Bertie who remembers how much Thomas relies on others and they decide to have a race to see who's faster.

Gordon, Henry, and James hate the extra work without Thomas and they decide to rebel after Gordon and James each have an embarrassing experience with the turntable their size requires them to use.

With the biggest three engines going on strike, the Fat Controller gets Edward to help out and hires a new tank engine, Percy. But with Gordon, James, and Henry giving the others a hard time, they remain the biggest problem to the railway.

Percy, Thomas, and Edward enjoy some free time for helping out, but Percy enjoys himself too much to be careful and is almost run into by Gordon - then has a delayed reaction and takes off backward.

The other engines don't believe Henry when he says he's sick, but soon even the crew notices and try to figure out what to do for him. It turns out the problem can be solved if a special kind of coal can be gotten for him.

Henry collides with a goods train while pulling "The Flying Kipper". The Fat Controller sends him to Crewe for repairs and he comes back with a new shape and a larger firebox meaning that he no longer needs special coal.

Gordon is jealous of Henry's restructure so tries to spoil his good mood by saying he shouldn't whistle. He also has to put up with a group of children attacking him.

Toby, a tram-engine with little work, gets a chance to spend time with people who truly appreciate him, like the Fat Controller whom he doesn't know, but soon faces his railway's closing down.

Thomas has unknowingly been illegally going down the public quarry way without equipment, so is considered a problem. But it may be a second chance for Toby, the unused tram.

James calls Toby and Henrietta "dirty objects" because of their shabby look. He tells them that you will never see his paint dirty. However, it's Toby who has the last laugh when James collides with some tar wagons.

Gordon scorns Henry for the accident that wasn't his fault, but Henry still gets to pull the Express, to his jealousy. Gordon doesn't want to pull freight-cars, so tries to jam the turntable, and sinks himself.

Thomas still likes to tease Gordon for forcing himself into the ditch. When he disobediently decides to explore a mine past the Danger zone and falls, Gordon is called in to dig him out.

At Christmas, Thomas remembers a friend who saved him and Toby a year ago, so decides with the others to throw her a party in return. But he and Toby have the hard job of trying to help her out of her snowbound house.