Before my forced career change, I used to work in a bearing factory.The ones we did were called plain bearings, like whats used on rod ends,, and hydralic cyinders. We acutually made them for Catapiller, and we had just started to make "maintence free" for EMD, before the company moved to Pennsylvainia.But we shared the plant with a ball bearing manufactuer.
Plain bearings: the outer races are cut from thick wall steel tubing, depending on the size. The biggest we did was 16" in diameter, to the smallest which was 1/4 of an inch. These were done at another plant. Machines called "grinders" would then machine the inside diameter to specified dimensions. Another machine would drill the lube hole, and a lube groove on the outside. Inner "Balls" would be machined from rough castings. Everything was sent to be heat treated, hardened and plated. They would come back, and the machine that I set-up and operated would mark the outside race, put a notch in it and crack it. This was to aid in assembly of the inner ball in the outer race. Using a hydralic press, the inner ball would be pressed into the outer. Sometimes the outer would be heated to 300 degrees to soften them.
Ball bearings start out from coils of steel wire, or steel rod, depending on the size, The company that shared our plant made them as small as 1/32" to as big as 2" balls. A machine called a "header" would cut the wire or rod and form it into a ball all in one operation. The rough balls would then be brought to a "Plate room", where huge steel plates with grooves machined in them. Here they would be spun in the grooves, under pressure til they were the correct size. This usually took hours, sometimes days to do. Then they were sent to be polished using the same method. After which they were sent out to be heat treated, hardened and plated. Cages and assembly were done at another plant.
Concievably Gary, a plant that size could do all the manufacturing right there, from heading, heat treating, plating, stamping the cages and assembly.
Possible loads in would be, boxcars of coiled steel wire, gondola of steel rods(Depending on the size) and tank cars of chemicals for the hardning and plateing process. And a flatcar with a "new" header or press.
Outbounds would be boxcars of finished products.
I know I rambled on...But I hope this helps.