Clive Spong was born in 1947, and was the only illustrator born after the original publication of the Railway Series in 1945. Spong received the first three or four Railway Series books when he was six in 1953. Like many boys in the 1950s he had quite an interest in steam trains, and had model railway layouts until his early teens.
Spong attended first Leicester College of Art, like predecessors C. Reginald Dalby and John T. Kenney, and then Coventry College of Art. After working in various advertising agencies for some years, he decided to go freelance and specialize in illustration. In 1982, his agent, Linden Artists asked if he would like to do some sample pictures for a new train book, following the existing style. The book turned out to be 'Really Useful Engines' and it all went on from there.
Until 2007 with the publication of Thomas the Tank Engine: The New Collection, very little information about the working relationship between Christopher Awdry and Spong was known. It was then, however, that Christopher commended Spong's "superb" work. And because of this, Spong remained the sole illustrator of Christopher's books and provided artwork for more Railway Series books than any of his predecessors. This was likely out of enthusiasm for the characters which he had appreciated in childhood, boldly coloured and strongly drawn, which the Rev. W. Awdry himself observed as being "accurate and consistent", even if they were emulating Dalby's work to some extent.
Co-operation also appeared to be high on Christopher's agenda, as he tried to provide new viewpoints and angles for Spong to illustrate to avoid making them overused and become dull and repetitive.
Spong seemed to evolve his style throughout his time as illustrator. First using solid and bold work to portray the scene to a more water-coloured style were engine's faces were more sand in colour than their normal grey. The further Spong went into the series, the further he went to making his own style in the Railway Series instead of emulating previous works.
After the Railway Series was put on hiatus in 1996, Spong primarily worked on illustrating educational books and did little in the way of fiction. However, in a September 2006 interview with Sodor Island Fansite, he stated he would return to the Railway Series if given the chance. He was as good as his word when the Railway Series returned in 2007 with Thomas and Victoria. And again, four years later, he was confirmed as the illustrator for the final book, Thomas and his Friends.
Spong has illustrated many pop-up books and other Railway Series spin-offs such as Thomas and the Evil Diesel, Thomas's Christmas Party, Thomas and the Missing Christmas Tree, and a rewrite by the Rev. W. Awdry of Thomas Comes to Breakfast. He also provided illustrations for the BoCo story library book with Jerry Smith in 2008.
- Really Useful Engines
- James and the Diesel Engines
- Great Little Engines
- More About Thomas the Tank Engine
- Gordon the High-Speed Engine
- Toby, Trucks and Trouble
- Thomas and the Twins
- Jock the New Engine
- Thomas and the Great Railway Show
- Thomas Comes Home
- Henry and the Express
- Wilbert the Forest Engine
- Thomas and the Fat Controller's Engines
- New Little Engine
- Thomas and Victoria
- Thomas and his Friends
- Thomas and the Evil Diesel
- Thomas's Christmas Party
- Thomas and the Missing Christmas Tree
- Thomas Comes to Breakfast
- Railway Map of the Island of Sodor (1983 edition)
- The Island of Sodor: Its People, History and Railways
- BoCo (with Jerry Smith)