A couple of corrections, Mr. "FF" are greatly in order...
The OA&B lines of the SP did not operate 500-series cars.. The 500's were used on the SP "red Electrics" in the Portland, OR area...
The only cars operated at one time or another on the old OA&B lines were the 300, 400, 600, 700 and 800 class cars. The 800-series (Cars 800-819) were the "SP Dinkeys" that ran between 16th St Station and Alameda via downtown Oakland, Franklin Street, and the old Webster St bridge.

"Ward Street" in Berkeley did not have a five track yard. Ward Street for the SP only had a spur into a freight station, switched by 0-6-0 steam locomotives. The FIVE tracks you mention did start at Ward Street in the middle of Shattuck Avenue and run uptown into Berkeley.
Only TWO were equipped with "catenary" (the SP). The Key System used single suspension type.
After a disagreement with the City of Berkeley, the fifth track was removed leaving FOUR.
In either case, the original FIVE tracks commenced at Ward Street and that is why I think you believe these five to be part of a Yard.

Henry