In the old days of timetable and train order, a work crew would have been assigned to that location. The order would've read, "Order # 405 (Four Naught Five) to Yard, Yardmaster, All Starting. Period. ). Approach Milepost 615 (Six One Five), prepared to stop short of signal and do not proceed until notified the way is clear by Maintenance of Way Foreman, or Signal Foreman, (or Flagman if so designated) Wayne Strom. Signed REP, Chief Dispatcher, JO (signature of operator).
The Rules meant that trains were to expect restricted signals and approach speeds according to standard rule book. They would have received a copy of this order at the previous Open Station. This notified the trains, crews, station agents the line ahead was being worked on.
I seem to recall that Southern/NS did not allow signals (sidings and switches) to be open, except in switching yards. On NS, if I'm not mistaken, if mainline switch was tampered with or opened, the Dispatcher would SEE it, and the signal would go Red. It was designed to prevent a wreck such as this. If I read the story correctly, the signals on CSX didn't work that way. I heard of
signals being tampered with by outsiders, thinking they could "have some fun". More than once, I heard an engineer, "157 to dispatcher! What's happened? The signal just went RED in my face", making for a rather abrupt emergency stop.
The same was true if a train is setting off cars and fouling the main. When the train occupied the block the signal went RED behind him in the block, and the previous block before that would go to "Approach". This provided "blocked in" protection, prevented headlight meets, and 'run-ins" where a following train caught up and ran the rear block signal. In the old flagging days, that's what happened to Casey Jones. They were doing something called a "Saw-by" where a long train that couldn't clear up fully could take siding, (or shove back thru the whole siding) and occupy the entire track. When the rear of the train cleared the main, the engine would be out at the opposite end of the siding, "sticking" out (fouling) main track. When the rear flagman signaled the superior train, he was to proceed slowly by. When his cab cleared the rear of the inferior train, the sided train would back back out onto the main, fouling that switch and clearing the head end. This would allow Casey's train to proceed past at restricted speed. That didn't happen, and Casey missed the flagman and plowed into the other train before it could clear the switch.
The trouble with this current system, and the reason for the "modern" way of doing things is reduction in force. Cutting jobs, Cutting overhead. In the old days, of which I was a part, there would be someone there to stop this from happening. Such rarely ever happened. Southern rarely had major derailments; they simply were positively anal about track maintenance and preventing accidents.
We had more agents, more work crews, more operators who had direct contact with the train crews. Gradually people were cut off, retired, moved out. Less people, more profit, but less oversight, IMHO! Correct me if I'm wrong. It's been a long time since I cleared trains. (Over!) Shortly after I bid back in at the shops (Week DAYS & 7-3:30 shift--YAAAAAA!), they went to track warrants and Dispatcher-controlled operations.
In short, the passenger train that wrecked would have had a speed restriction in that area, or a RED signal. But they do it differently these days. I suppose it is "better", but they sure seem to have more wrecks!