The UP Gila Sub is the ex-Southern Pacific Sunset Route that runs 255 miles from Yuma, AZ, to Tuscon, AZ. When I found out of a possible signal replacements coming this summer, I made plans to go get the remaining SP signals. Plus UP has been putting double track in along this route, and those plans also have replaced alot of the old SP signals too. Roughly only 85 miles of original SP trackage is left with old signals along the Gila.
Between Dome and Wellton, there is 16 miles of original SP double track. The 2nd track was built in 1926, with the original main built by the end 1879. While it shows 2 main CTC, the trackage is signaled basically in one direction like traditional ABS. Here a auto train from Benecia, CA, to Spring, TX, (Houston) splits a pair of ex-SP search light signals at MP 763, about 14 miles west of Wellton. The Gila Mountains are seen in the background. It is still old school here with the signals and code line, but don't worry, changes are coming too soon!
Photos showing the railroad pole lines. The pole line used four basic electrical circuits - telegraph, telephone, signaling, and power. Modern technologies of fiber optics, microwave, radio, satellite, and computers have been replacing the pole lines.