Emett, a cartoonist and constructor of kinetic sculpture, completed the train in 1984. Titled A Quiet Afternoon in the Cloud Cuckoo Valley, it has been described as his finest work.
Emett created the Far Tottering and Oyster Creek Branch Railway, a fantasy line made for the 1951 Festival of Britain.
This sculpture of the train from that line was initially a commission for a shopping centre, but by the time the sculpture was completed in the mid-1980s, it was no longer required. It was then bought and exhibited in Spitalfields Market in London in 1992 but later put into storage before, nearly being scrapped.
It was luckily saved and restored with a digital control system added and displayed in 2014 at Birmingham Museum and Art Gallery.
Judith McNicol, director of the National Railway Museum, said: “It’s not every day you have the opportunity to acquire something which combines that seriousness of purpose, design, and skill with, well, such a sense of fun. Rowland Emmet’s work bridges the worlds of engineering, modelling and railway enthusiasm. And this kinetic sculpture is characteristic of his sometimes eccentric passion for railways, depicted in a whimsical and quintessentially English setting.”
Jon Baddeley, Bonhams global head of collectors’ department, said: “Rowland Emett regarded A Quiet Afternoon in the Cloud Cuckoo Valley as his finest work and I am delighted that it’s found such a prestigious home, and will be available for future generations to enjoy.”
The sculpture had been due to be auctioned on September 3 but was withdrawn from sale due to the private sale to the museum.