Airline Empties. On December 4, 2019, BNSF Railway 8420 (SD70ACe, EMD) leads an empty coal train across the St. Charles Air Line in Chicago, Illinois. Chartered in 1852 as the Chicago, St. Charles and Mississippi Air Line Railroad, it would eventually become majority owned by the Illinois Central and thus Canadian National Railway Company. Shortly after this photo was taken, the Air Line and its counterweight bridges were taken out of service for rebuilding by CN. Although there have been periodic progress reports, it remains out of service to this day with no date certain for return.