One little correction. UP doesn’t have “DS”s. Just “TD”s that stands for Train Dispatchers, and the CAD computers call them “D” for Dispatcher for short. UP also has “TTD” for Terminal Train Dispatcher. BNSF is the only railroad that calls their Train Dispatchers “DS” and that remains from the Telegraph days when a station online Telegraphed the Dispatcher a message, they began their message with DS.