Season 12 of Adventures on Rails contained ten episodes that aired from April 5th to June 15th, 2013.
The 1960s was quite a decade for the North Western Railway and Skarloey Railway. With new projects, engines being built or restored, and lines. The Skarloey Railway opened the Lakeside Loop, and the North Western started Project 11001, along with the return of an 'ol' friend. Percy also... you must read the stories for yourself to find out.
- Diesel Does it Again- Diesel revisits Sodor, but proves to be more devious than ever.
- Project 11001- Robert Means introduces a new, expansive project for the North Western Railway.
- David's Restoration- In 1958, the Fat Controller saved a J11 from scrap, four years later, he is restored.
- Bowled Out- When a Diesel visits Sodor and is rude to the engines, they plan to get back at him, but the solution comes sooner than expected.
- Percy's Important Job- Percy is assigned an 'important' job.
- Dirty Percy- Percy realizes the tough work in the Mines.
- A Surprise for Percy- Percy finds life boring at the Mines, but is in for a surprise.
- Freedom at Last!- At last, Percy can go back to Ffarquhar... maybe...
- Clever Thinking- David's BR expirence saves a nasty accident.
- Centenary of the Skarloey Railway- The Skarloey Railway celebrates their 100th anniversary, along with Skarloey and Rheneas' 100th anniversary.
- Donald and Douglas
- Diesel 10
- The Diesel
- Sir Handel
- Peter Sam
- The Truck
- Sir Topham Hatt
- The Thin Controller
- Delete (non-speaking role)
- David *- a J11 rescued from scrap used for goods on Edward's Branch and the Main Line.
The season will have ten episodes taking place from 1960-1965. It will show David's restoration, the plan to build the Bulleid Diesel, Mavis and BoCo's arrivals, and opening of the Tidmouth-Arlesburgh Branch Line. It will also see Diesel's return to Sodor in 1961. Percy at the Coal Mines Marathon is now confirmed to be a stand alone marathon that takes place during this season. However, it was then announced that it would be back on to the season.
- This is the first season or now called 'books' that have a foreword. It will also have an afterword.