The term "fat controller" has since been adopted in various contexts in the English language, beyond the sphere of the original stories, usually in reference to someone who runs a railway.

When Henry refused to leave a tunnel, the story says that "A fat director, who was on the train, told the guard to get a rope".

The name Sir Topham Hatt is first mentioned in the foreword to Henry the Green Engine and also appears on his luggage trunk in the same book in the story "Percy and the Trousers".

These events are an opportunity for children to meet characters from the books and television series (or at least, engines that have been "dressed up" to resemble them).

These events are invariably presided over by a Fat Controller, played by a railway volunteer of appropriate age and build.