Southern Pacific Railroad Company

Although this business doesn't appear as a separate listing in the 1925 Chandler City Directory, 

Chandler resident George Gann is listed as an agent for the company.

The 1929, 1930 and 1931 directories  said H. M. Hale was the agent and that SP was located at Delaware, at the corner of 
Commonwealth Ave.

Southern Pacific R R Co. Station is listed in the 1932 Phoenix Telephone Directory, Chandler section, with the phone number 9.