@Charred - I think that’s a fair analogy, although I am no mechanic myself.
The thing that I wonder about is the use of compressed air instead of steam to provide the locomotion. I would think that steam boilers would deliver greater power and the steam would act as a better lubricant to the pump’s metal parts.
I believe it would take a lot more compressed air to deliver comparable force. I bought compressed air in a can once to dust off my computer monitor, and while it can be very forceful, it tends to run out in a hurry.