I had seen this model railway video some time ago,

https://www.youtube.com/watch?v=FZy9kQhg-iI (45 minutes 5 seconds)

Yesterday, the following video was on the title page of YouTube here, it is marvellous, perhaps especially now from a perspective of 2024 looking back at experimental work from over seventy years ago. This was an era from just before nationalisation of the main railways of Great Britain (in 1948) to the few years after, when locomotives that had started as projects of the private railway companies became projects of the nationalised British Railways.

https://www.youtube.com/watch?v=doBPp3ZfgLc (15 minutes 7 seconds)

There is the following wikipedia page

https://en.wikipedia.org/wiki/British_Rail_10100

William