Courtesy of the San Francisco Public Library
View this photo at sflib1.sfpl.org:82
BH Photo #483380
The original turntable isn't a pony truss, hence the two entries.
The later pony truss turntable is likely the more notable of the two, but both deserve an entry, considering John Marvig has proved that railroads liked to reused turntables as bridges, both on their mainlines and as road overpasses.
Was only just now making the other page anew - if you have better info, no need for two different pages for only a difference in turntables. Please just combine the pages.