Gato Pumphouse explained *LINK* *PIC*

In the case of Gato pumphouse, looking at the piping in Bill Pratt's photograph, I see no provision for one. I linked again to Bill's picture below so I can describe the arrangement without readers having to flip back to Bill's message.
Some of the piping confuses me a bit; but it looks like the pump intake comes in from the top of the vertical boiler and goes to the intake of the steam engine end of pump in the center of the picture. The pump's exhaust appears to come from the bottom center of the picture, and goes to the exhaust stack of the vertical boiler, where there was probably a nozzle to induce a draft through the boiler (like a locomotive).
See the cover plate at the bottom of the pump end on the right? The pump's suction came in from the other side of the pump from a pipe through the wall of the pumphouse. (Having flanges on both sides allowed you to pipe the pump up from either side.) That tall silver pipe behind the pump is an air chamber. Air is trapped in it; as the pressure to the pump drops; the water level in the chamber goes down. As the pressure rises, the air is compressed again; this chamber helped to even out the flow to the pump.
The pump's discharge is on top. Clearly visible is the air chamber on top, which is typical for a Cameron simplex pump. The discharge pipe exits to the right in the picture; the fact that has more than one branch suggests that maybe a locomotive's tender could be filled directly from it.
The small pipe coming off the pump discharge and going to the boiler probably allowed the water pump to server as a boiler feedpump for the boiler. The oil drum behind the pump holds steam oil; a small line just visible in the picture injected oil into the steam line of the pump. There had to be way to force the oil in under pressure; there is probably a displacement lubricator either in the barrel or out of sight that did just take; I guess taking oil straight from the barrel.
Getting back to your original question; in order to allow a steam locomotive to run the pump; I would expect to see a "tee" off the pipe leading to the pump intake, with a hose that could then be coupled to the locomotive's steam turret or some other attachment point. I don't see anything like that in Bill's picture.
Anyway, that's how Gato Pumphouse worked, as far as I can figure out. It was probably more than most readers wanted to know. But it is a neat visual study in how a steam pumphouse worked. " />