Long been one of my favorite movies, and having grown up in the Greater Bay Area, I am familiar with many if not most of the scene's locations!
Not so hard to turn a steam engine into a pump, especially if you are only pumping air. Low volume to be sure, but in the situation depicted, you'd not want more than a small volume anyway.
I'd love to have an E-Type done like that one in the movie ..... even though it is a bit morbid and generally I avoid such things, but really .... WOW!!!