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We are about a mile from the crossover at Sandcut. This section from Bakersfield to Sivert (later renamed Sandcut) had a second track placed into operation in August 1922. The double track was extended to Bena in 1928. Train 199 (Extra 5604 West) glides by the eastbound grade signal near mp324 on June 11, 1980. Train 199 was an expedited TOFC train that also handled UPS traffic. You can tell that the lead unit is staying close to Tehachapi from all of the accumulated grime. Note the circle G plate on the signal to the right. This is called a grade signal. Trains may pass a red grade signal at restricted speed without stopping. This lets trains keep rolling. You will see a train taking advantage of this later in this series on the east side of the pass.
It was rare to see a U25B or a GP35 in the Tehachapi Mountains. These units were common on the Coast Route and on the Sunset Route. On the morning of May 30, 1978 engine 6737 leads a short train of side dump ballast cars through the crossover switches at Sandcut. This is the beginning of CTC for the mountain. The work to installed CTC over the single track section between Bena and Tehachapi was completed in June 1943. CTC was extended from Bena to Sandcut in 1961. I think the CTC board in the Bakersfield depot for the mountain was upgraded at the same time from the older US&S machine with levers for every switch and set of signals to a new push button console style. The rest of the line from Bakersfield to Mojave was directional double track. The letter SA on the signal means semi-automatic. That is kind of a dumb name as the signal will not clear itself automatically. It is still under the dispatchers control and protects the motorized crossover switches. If this signal is red a train must stop and get permission from the dispatcher to pass. What it does tell the train crew is that they are moving out of CTC territory and entering automatic block signal territory. In the old days there would be a sign with the words "End CTC" to designate this change. On the back side of that sign would be another with the words "Begin CTC" to alert crews on trains moving into CTC territory that the signal rules are changing.
Extra 5105 West comes off the mountain and heads into the setting sun on June 10, 1980. The tracks are headed west by northwest and during the month of June the sun sets slightly to the north of this heading, so we get sunlight on the north side of this westbound train. Disk 40