There's a museum in Sheffield (Kelham Island
http://www.sheffieldontheinternet.co.uk/kelham.html ) and they have a steam engine from a steel rolling mill - they actually run it to show you how it worked.
It's absolutely HUGE, and because you have to roll the steel while it's still hot, it's VERY fast - and it changes from full speed forwards, to full reverse, in about half a second - very scarely to watch!. Probably used in the same plants as the APE gear?.