Prototype Railroad Galleries > UP's Cal-P line - Hercules & Pinole (05/10/07) (66) > dscf3487.jpg
Looking east to Sacramento and Roseville along the westward main. The closest signal on the left side of the track controls eastward movements through the CTC plant. The switch to the siding has it’s own signal controlling movements from the siding to the main. The siding signal is located behind my position on the left side of the siding.
Eastward movement on the left hand main to the signal ahead protecting the crossover is controlled by the signals behind me, around the curve at Pinole. If the siding switch is thrown for the siding, the signal at Pinole will go red protecting movements toward this siding switch.
Why not just control the siding by moving the crossover signal closer to the camera to the other side of the siding switch where I am standing? The most likely reason is signal visibility. By controlling eastward movement on the main over the siding switch with the signals at Pinole, the Hercules crossover signals are located further away from the curve behind my position and crews have more time to see and respond the crossover signal.