I know this is going even farther into the world of railways than some here would care to see, but I have been a fan of my own country's (US) railroads since I was very small and saw some of the last steam locos in service in my part of the US.
I am always amazed that so many freight types without leading trucks made it into passenger service in Europe. Leading trucks (bogey wheels) are necessary for high speed stability and ability to negotiate curves at the speeds typical of passenger (or high speed freight) operation.
The 0-8-0 type was first built in the US in 1844 and was relegated to slow freight work only. In the latter part of the 20th. century this type was mostly used as a switcher (shunter) for yard work.
Sorry for "derailing" the conversation.
Great work you are doing Foo'bar.