Could be that somebody who needed to be fired wasn't.
Rode up front on an Amtrak up to Sacramento, 'n' talked with the Engineer some of the way. The signals are regarded as God's Right Hand by railroad men; ignoring them gets you fired.
What puzzles me is that it didn't seem there wasn't any automated backup. The New York Central had automatic signal detectors on-board their loco's way back in the early days of diesel power. If an Engineer missed a "stop" signal, an alarm would sound immediately, requiring immediate response from the Engineer. If that response didn't come, the automatic detector would trip the brakes, and stop the whole train.
Another thing: signal control responds -- at least in part -- to what are called "block occupancy detectors"; sensors that govern a whole section of track, called a "block". If a train enters a block, that should cause the signals on both ends of the block to change "aspect"; from green to yellow, or from yellow to red, or vice-versa depending on direction of travel.
If my train's in "block 1", the crew of a train coming the other direction will have the green at end of "block 3" that is farthest from my train. They'll have the yellow at the end of "block 2" that is farthest from me, and they'll have the red at the far end of "block 1". All of that is triggered by the occupancy detection equipment in block 1 where my train is.
As my train moves from block 1 into block 2, the signals for oncoming traffic change two full blocks ahead of me. The signal at the far end of block 2 goes from green to yellow, and the one at the far end of block 2 goes from yellow to red.
In practice, it's more involved than that, and actual lamp colors vary on different railroads, and then there's radio, too, that enables more flexibility, but that's a basic description.
In order for two trains to meet in a head-on, one of two scenarios would need to happen:
If my train were in block 1 when the oncoming train was in block 3, the other crew would have to miss the yellow as they entered block 2, and I'd have to miss the yellow (caused by the other train being in block 3), as my train entered block 2. IF the other train entered block 2 before my train did, I'd have to miss the red (caused by the other train already being in block 2), as my train entered block 2. If either of those two situations happened, both trains would end up in block 2 the same time, and there wouldn't be any more signals between us that could give any indication that we needed to stop our trains. Furthermore, since both of us had missed the signals coming into block 2 from our respective ends, we'd both still be highballin' it when we finally got to where we could see each other. At that point there'd be some yellin' in both cabs (probably some real coarse language, and the Engineer shouting at the Fireman to bail out), brakes would get slammed into "Emergency", and -- at least in the old days -- both crews would probably make an honest attempt to "join the birds"; that is, leap out at the last moment and take their chances.
If my train were in block 1 when the oncoming train was in block 4, the other crew would see green as they entered block 3, and -- if I entered block 2 at the same time the other train entered block 3 -- I would also see green as I entered block 2 and BOTH trains would be going at maximum track speed. If I entered block 2 a bit after the other train entered block 3, I'd see a yellow telling me to slow down, but both trains would still be heading toward each other with just ONE remaining signal between them: the signal between block 2 and block 3. That signal would be showing a red aspect in BOTH directions. If I or the other crew missed that signal, there'd be a head-on with one train stopped and the other still going at the track limit.
That second scenario had railroads wiring block occupancy detection to trip signals to yellow TWO blocks ahead, not just one, so as to provide an entire block of additional "padding" between oncoming trains. For a train stopped in block 1, say, an oncoming crew would see green entering block 4, yellow entering block 3, yellow again entering block 2, and -- finally -- red at the limit of block 1.
I don't know how it's set up down there in Chatsworth, but someone definitely wasn't paying attention, and there'll be wrongful death cases coming out of this before it's all said and done.
I just hope Ike is nicer to the folks in Texas than the Laws of Physics were to those people on that rail line.
Thanks for the info. Typically as a condition for a commuter rail network to run on a freight line, the commuter rail indemnifies the freight line (UP I imagine) for all damages and legal liability.