Bethlehem San Francisco was founded as Union Brass & Iron Works in 1849, by Peter Donahue, one of San Francisco's three Donahue brothers, who were known as the "iron men".  It was sold to Bethlehem Steel in 1906 but continued to use the Union Iron Works name until 1917, after Bethlehem acquired Quincy, Sparrows Point and a number of smaller yards, and standardized the yard names and the hull numbering system.  The San Francisco shipyard was expanded in 1911 by the acquisition of the adjoining Risdon Iron Works, which had built locomotives, and this facility was used in WWI for destroyer construction.  The yard remained in continuous operation throughout the inter-war years and was the only major shipbuilder on the West Coast prior to WWII.  Bethlehem Steel sold the yard to the City in 1982, for a dollar.  It was then leased to Southwest Marine under the name San Francisco Drydock and continues today as a division of BAE Systems.  See it from the air on Google here.

The Alameda shipyard, formerly United Engineering Works, was added in 1916, at the onset of WWI, to build standard cargo ships for the U.S. Shipping Board.  After WWI, the yard was converted to ship repair, although it built 10 troopships and 21 tugs in WWII.   The Alameda yard closed in 1956.  In the table below, the ships that were built in Alameda are identified by an A after the hull number. 

There is some confusion with respect to this company's hull numbers, particularly as they relate to which vessels were built where: if anyone has a definitive list, please send a copy to timcolton@aol.com .