Southern Pacific Equipment Lettering

@HiramO posted:

When was Southern Pacific equipment lettered "Southern Pacific Lines"? It seems a simple question, but I haven't found the answer...

Prior to 1946, the "Southern Pacific Lines" was used on pretty much all rolling stock. Beginning in 1946, the SP began changing their steam locomotives to the large "billboard" 'SOUTHERN PACIFIC" lettering. Passenger equipment and freight cars also began using the "SOUTHERN PACIFIC" lettering.

Thank you!