Rolling Stock

Rolling stock, that's not something you ever hear today, but once I thought about this shot the words popped into my mind. Better that than them being stuck on tip of my tongue (ie not being able to remember them)! And what is 'rolling stock' you ask (let's just pretend you did, hmmm'kay?) Why, Wiki says it's "the collective term used to describe all the vehicles that move on a railway. It usually includes both powered and unpowered vehicles, for example locomotives, railroad cars, coaches and wagons." That's the third new thing I've learned today. You?