The History of Plane Bearings

There's no federal regulation on plane bearings, but Association of American Railroads has banned them from interchange service as of 1991. Only time you really saw conventional rag bearings is usually on maintenance away equipment because that stayed internal. So they last forever and they were overbuilt because they're built during World War II or right after it. Some of the ballast cars I worked with were about as old as my grandpa.