Good find. I especially like the photos from 1979 showing action on Belmont Avenue and around Reed Candy's plant a couple of blocks south on Lakewood.
My guess is that the train is using the track north of Belmont as a tail to then shove down the Reed spur. That covered hopper probably has sugar and the tank car corn syrup for either Reed or Peerless.
The tracks were cut back circa 1973 on the north end down to Racine Avenue and just south of Roscoe so that service could be maintained to a fuel oil dealer on the west side of Racine. Then they were cut back again to Melrose with just enough track left in place for use as a tail track to access to Reed spur. When Reed closed this plant in 1983 the tracks were once again severed, this time at Diversey. An isolated bit of track is still in the parking lot of the business at 1231 W. School.
Attached is a screen shot from Google Streetview showing the isolated track at School looking north as well as one from 1984 of the same spot, but looking south towards School Street. Hard to believe that 30 years later this short section of track would still be there! Note the remains of the wig-wag style crossing signal and evidence of at least one other track to the west. Finally, a shot of the tail track looking south from Melrose to Belmont from 1987 with the Best Brewing complex towering off in the distance on the right.