A very quick heads-up and a link to the wonderful website, RAYLWAY WONDERS OF THE WORLD.
The website collects material from the 50 monthly installments of the two-volume Railway Wonders of the World, an encyclopedia / travel book / railway book published in the UK between 1935 and 1936.
The website is a treasure trove of information about railways, trains, foreign countries, and famous lines like the Orient Express and many other lesser known services. The pages are fully indexed and include external links to Wikipedia and other sources.
It is an absolutely indispensable resource for anyone writing (or reading) historical fiction.