Affectionately known as a Standard class 4 clank, 'cos that's the noise the coupling rods make, at least on all the ones I've seen over the years.
Joe Brown the musician was a locomotive fireman in his early days, and a few years ago he was reunited with one of the class that he actually worked on, number 80079, a resident of the Severn Valley Railway.
How's that for trivia, (may come up in a pub quiz sometime.)
Gordon.