Here's a photo I took on December 06, 1984, THIRTY-NINE YEARS AGO, of an Espee Shippers Special that ran from L.A. Harbor to the California Steel Industries plant in Fontana. This was when negotiations were in the works to bring imported slabs of steel into the harbor from Brazil and ship them by rail to the steel plant, which they continue to do to this day. I believe BNSF has since wrestled this business away from SP (later UP).
Here we see the train coming off the La Habra Branch from Slauson Jct. and is going around a transfer track that will get it onto what was then the Puente Branch where it will proceed to Bartolo. There, the train will run for 6.9 miles on trackage rights over the U.P. Los Angeles Sub. This is the former LA&SL route that was used by the "City of Los Angeles" and is used by Metrolink 400-series trains. At Puente Jct. the train will re-assume SP rails all the way to Fontana. UP now calls the Puente Branch the Los Nietos Branch.
When SP was still independent, the routing from Slauson Jct to D.T. Jct. and the Puente Branch to Bartolo was important as it kept Espee trains running from the Harbor area to Industry and West Colton out of downtown Los Angeles. After UP took over the SP, this routing lost a lot of its importance as trains could now proceed up the Alameda Corridor and use the UP's LA&SL line via East Los Angeles and Montebello and they can switch to former SP lines on the west side of Pomona. Consequently, the transfer "balloon" track that the train is proceeding around in the photo has been taken out of service.
When I took this photo, I was standing on an embankment of the 605 San Gabriel River Freeway and the bridge you see in the distance is Slauson Avenue where it crosses over what is currently the UP's Los Nietos Branch and the BNSF's San Bernardino Sub. The photo is looking west to northwest. That bridge had to be re-built as BNSF expanded their double-track subdivision to three tracks. A think forest of eucalyptus trees has since grown in the area contained within the "balloon" transfer track around the horse stables seen above the lead unit. You can also see the tall buildings of downtown Los Angeles above the first and second cars.