truth is that it was to blame that shift if something went wrong. That is not how they phrased it but that's what it was for. they said it was to verify how many and what types of cars got moved down the line and not into the repair bays so that they could find out problems and correct them.
most of the inspectors had a different color wax crayon(yellow or red mostly) that they ticked of each sections operations. so if you see a yellow or red crayon mark on the interior behind the panels that's an inspection mark for that section of parts being put on. engone bays usually had white crayons or yellow depending on the color of the car. but all the rest had red or yellow check marks or circles or a line(check marks -=ok ,circles= repair bay line = done fixed from repair bay) it was the same at Trenton engine with the crayon markings for the engines too (at least in the late 70's when I got bumped out of the glass plant for 3 years)
each dark blue bin was about 4 ft. by 4 ft and 3 ft tall. with a white 6 inch tall number painted on it (all 4 sides and the top panel had the paper sticker with the same number on it) for each different part. I remember the shocks because a hi-lo driver knocked over a full bin of them and they jammed the assembly line for over 30 minutes. yeah the guy got time off right away too! Man the foremen were PISSED at him and some of the line workers were throwing them in a different bin when they got there and went ballistic. the foremen made them take down both bins and put 2 new ones up while the line was down and they had to sort by the little bitty part numbers on the shocks in BOTH bins, there were a LOT of shocks in those bins. I was glad I didn't have to sort them out.
I also saw them run the forks through a rack of 50 windshields, drop a pallet of engines off the railroad car and drive off the end of the loading dock without a truck being there to drive into the same day, I think they fired that guy. Hi-lo drivers got away with a lot in the mid 60's and early 70's.
72-ish till 2003 I worked at 3 different plants. McGraw glass plant (yup made them 64-66 barracuda rear backlights all they way till 1976) Trenton engine and last and least Jefferson assembly 10 years after i visited it as a dealership mechanic it still hadn't changed except to get ummm more dangerous to go to and from work (and that was inside the plant and parking lot.) I was pulled back to the glass plant in about 10 months. I would not have lasted much longer at Jefferson assembly.