Heated Bunker C

Jim,

Southern Pacific used oil (Bunker C) for the vast majority of its steam loco fleet from the early Twentieth Century on to the end of steam.  Only the modest piece of former El Paso and Southwestern in Arizona and New Mexico used coal due to purchase contract requirements.  Most other railroads that burnt "oil" also used Bunker C--a very heavy, tar-like substance at the bottom of the oil barrel.  Bunker C needed to be heated to flow.  

With that background, the basic fueling arrangements on the SP included an oil storage tank (often quite large) and a boiler supplying steam for heating the oil as it was moved from the storage tank to the standpipe on the service track.  The steam heat often was supplied by a boiler that supplied steam to the overall engine facility, often from a boiler house located near the machine shop and roundhouse/service bays.  The helper station at Oakridge, Oregon, (Cascade Line) which I model was a prime example of this.  So also was the more modest facility at Alturas, California on the Modoc Line.  Dunsmuir, California (the south end of the Shasta-Cascade Line) had the same arrangement--boiler at the machine shop.  ALW Lines makes a great HO scale model kit for a standard SP boiler house--patterned after the one at Oakridge, but also very similar to the one at Alturas.  

The other major consumables that had to be accounted for were water and sand.  Water was also delivered via a standpipe at the service track, while sand often was supplied from a sand house with an elevated sand bin for gravity feed.  

You are correct for the location of the oil bunker in a tender.  The oil bunker was located forward on the tender in the same space coal (or wood in early days) was stored.  The much greater volume of water carried in a typical tender was aft of this bunker with a small extension under the fuel bunker for easy connection to the locomotive.

Bill Decker, McMinnville, Oregon

Oil

A large tank, typically the large diameter storage tanks.  The tanks could be next to the service track or 1/4, 1/2 mile away.

Small pump house, 10x10 or so.  Could be brick or metal.

Underground pipe.

ATSF Argentine Yard, KC :

San Bernadino :

And many tenders ...

And many (all) tenders in at least cold climates had flexible pipes from the locomotive supplying steam to circulating heaters to keep the water and oil warm so it would flow freely.

SP Port Costa Terminal

Here is a plan of SP's Port Costa yard and engine terminal. Port Costa was one of the ferry landings for the ferries SOLANO and CONTRA COSTA which crossed the Carquinez Straits until the bridge at Martinez was built. http://cprr.org/Museum/Solano/images/I_ACCEPT_the_User_Agreement/Solano-PlansModelPckg/OtherSources/Port_Costa_Plan.gif

And a photo looking towards Oakland. http://3.bp.blogspot.com/-fta9cUpLMaY/UrXPd-75iUI/AAAAAAAAGr8/lw9he7f5baY/s1600/P+Costa+56.jpg

Ron Plies built a diorama that was featured in RMC if I recall correctly. Here are photos: https://www.pbase.com/tracktime/wpm2005
/> One photo is to the right in the bottom line and further four in the first line of the next page: https://pbase.com/tracktime/wpm2005&page=2

I hope this helps a bit.
Regards, Volker