From a 1926-vintage issue of Railway Signaling Magazine comes this reprint (courtesy Google) by Charles H. Lay, General Construction Foreman for the PE, entitled” “Pacific Electric Moves Electric Interlocking Machine ‘Ensemble'”. It shows the physical relocation of the interlocking machine from the old wayside tower to the steel bridge spanning the Four Tracks.
“Pacific Electric Moves Electric Interlocking Machine ‘Ensemble'” (1926)2017-07-022018-05-27https://www.pacificelectric.org/wp-content/uploads/2018/05/peryhs-logo-350.pngPacific Electric Railway Historical Societyhttps://www.pacificelectric.org/wp-content/uploads/2018/05/peryhs-blank.jpg200px200px
The article explains why Amoco Tower had to be relocated from a typical interlocking tower to an addition on a signal bridge. This has probably puzzled many PE observers who were curious about the unusual structure. It might even be seen as a harbinger of things to come, with railway facilities being pre-empted by street and highway construction.