RULES WRITTEN IN BLOOD. In September of 2002, a Norfolk Southern (NS) train derailed near Knoxville, Tennessee. There was a hazardous material spill and an evacuation that didn't quite chase Insta Pundit. The November issue of CTC Board reports the main points of the National Transportation Safety Board investigation, which is available as a .pdf file here. (The mother lode of train wreck reports is here.) Why the derailment? Earlier in the day, an eastbound train crew discovered a problem with a track switch. As the switch was a spring switch, and the train was making a trailing point move, the dispatcher allowed the train to proceed. The train pushed the switch out of the way in such a way that it appeared normal to a cursory inspection. A maintainer made such a cursory inspection, oiled the switch points, then stuck around for the next westbound train, which pushed the switch points out of alignment. Result: derailment. NTSB finding: "The signal maintainer’s initial visual examination did not reveal a problem, but he did not operate the switch before train 15T passed over it. NS operating rules did not specify that an inspection of a possibly defective switch should be completed before trains are allowed to operate through the area. NS procedures also did not address the reduction of train speeds after receiving a trouble call about the condition of a switch."