I've noticed during visits in the summer that many times there is a lot of wheel squeal when trains are pulled around this curve. If the squeal is because the flange is being driven against the rail, then that would exert a lot of lateral force on the rail. This check was happening around 4pm. The last photo was the last check he did. Maybe the checks he did had good enough results that he could assume the rest of the curve was OK. According to a satellite map, he was checking the end of the curve since this track normally carries eastbound trains.
Then on my way home from this field trip to Lemont, IL, I saw three vehicles and two men working on the BNSF/CB&Q signals at Forest Avenue, Downers Grove, IL. Every since they switched to the new signals, the crossing gates at Washington, Main, and Forest have been known to go down when they shouldn't and to stay down when they shouldn't. After monthis of false gate closings, I do hope they can figure out what is wrong and fix it. It really ties up traffic on Main when they "bounce." One time I saw them go down three times for the same train because the first closing was way too soon. The new signalling equipment has been a good example of "it takes computers to really foul things up."