For several years in the early 1990's, the LTL Trucking Co. I drove for had a terminal @ 50 Quint St. ( More recently this facility was / is used as a bus yard. ) This is right on the corner where Quint turns @ Islais Creek; the track then heads kinda East across 3rd St. During my many trips there, I only saw Espee switchers on this line; never any Santa Fe. The First Quarter, 2011 edition of The Warbonnet from Santa Fe Tech has an excellent Espee map of the rail lines in the area circa 1926. This map lists the trackage in the Quint St. Stockyards area, coming down Illinois St. from China Basin & crossing the creek on 3 St., as joint SP / SFe trackage. This same map is also in the WP Timetable book - 'Track & Time' by Jeff Asay.
I would agree with the assessment of the general area, as it was not uncommon to have to remove the natives who had taken up residence in & under empty trailers we left around the corner. I would often take a Sunday night run up from Orange Co., arriving early Monday AM before the dock crew. Although I became quite adept at looking like a cop, with my 4 cell Maglite held over my shoulder, several other company drivers refused to go to this yard due to the local indigent population. Also, Espee used to send a gumshoe & a large tow truck ahead of the switcher to clear any parked trailers from the R of W, which was the signal for all the drivers to hurry out & move the equipment before it was towed away. All in all, I enjoyed the challenge of pulling doubles across the Bay Bridge & down the small streets in the area; the sight of an Espee crud pulling 89' container flats loaded with Dirty Dirt around the curves on the Quint St. lead was a huge bonus.