Southern Pacific Shops in Sacramento

One day my school took a field trip to the SP 'shops'.  While there, I remember passing some big railroad car wheels... just stacked up there in the area.  I also remember seeing some kind of glowing furnace.  Somewhere in the course of the visit, I saw my grandfather, Victor Lo Forte, Sr.  I don't remember what he was doing, just that he was in that area.

Have a picture of my grandfather and his co-workers titled Bob Koker Retires, 1937.  I haven't been able to locate where on the Shop site it was taken.  Anyone able to help?  According to the 1930 census, Robert S Coker was an Core-maker at the Southern Pacific Foundry and my Grandfather was an Iron-molder at the Shops.   I would love to know who the other folks in this image are as well.