Navigating the S-curves at Frost, ironically located in the Mojave Desert, is BNSF Guaranteed Service Intermodal train Q-ALTSBD6-19, ferrying hundreds of shipping containers from Alliance, Texas, to San Bernardino, 44 miles ahead. The "usual suspects" – in other words, late-model General Electric diesels – are powering this train: BNSF ES44C4 8325, ES44AC 5863 and Dash 9-44CW 4168 are the cookie-cutter diesels on this train. They pretty much all look alike, but there are a few details (very few) to make them different. A bit.
As for this location … In the days when this line was signaled as double-track, current-of-traffic (Rule 251), the line between San Bernardino and Frost, over Cajon Pass, was laid out for left-hand running so that eastbound trains used the easier gradients uphill from San Bernardino. Santa Fe built a "natural crossover" just south of downtown Victorville, at a spot named Frost, where the westbound line climbed up and over the eastbound line as the tracks curve from northeastward to northward. Because there is no longer a real need for the "natural crossover", there is also a set of crossovers, with the usual signals, at Frost (MP 38.0), just at the north end of the ramp up to the crossover bridge. An upcoming program to triple-track this section of BNSF's Cajon Sub will, sadly, soon remove this distinctive, if archaic, track arrangement. And a new highway bridge being built has already rendered this view difficult, if not impossible, so access these days. Not to sound like an old fart (but I'm allowed to, as I am one!), but progress isn’t always a railfan's friend. (Victorville, California – April 21, 2021)