I'm not sure which locomotives the ones in the book are based on. According to Michael Farr's
Complete Companion, the engine that pulls the train on p3 is a BB type - if you search for "BB locomotive" you should find a few similar models. There's an image in the book which shows Hergé's original photograph used for the drawings, even with his pencil-drawn grids over the top of the photo.
As far as the British engines are concerned, I'm a bit stumped. I really don't know what kind of engine the passenger train's is - I looked up the Class 47, and it doesn't strike me as being close enough. As M. De Moor did all the sketches first-hand, I'd imagine that the engine existed at one point as we see it in the book.
For the goods train, I'm favouring the Metropolitan-Vickers 'CoBo'. There's a gallery of images
here, but if anyone wants to reminisce a little, it was the same model for Boco in the Rev W Awdry's
Thomas the Tank Engine books.
I didn't know that's when the blue colour scheme came into use, but I knew I'd never seen the green one as in
The Black Island. And as well as BR updating their rolling-stock's livery, colour television came into use in the UK soon afterwards. Poor Hergé - talk about raining on your parade ...
Edit : I've come across a photo which looks even more like the goods train than the BoCo.
This BoBo (to anyone who may not know about railways, I'm not making these names up) which was sadly scrapped in 1980, looks rather like De Moor's goods train. There's also
this Hymek Class 35 which bears a passing resemblance. The hunt goes on ...