Bucyrus [snipped] Every engineer knows that even when he has a route lined up through an interlocking plant, he has to watch for, and expect that route to be taken away by a change in signal indication. . . .
Otherwise, your analysis and opinion of the facts and the NTSB's report seems to thoroughly explore all of the possibilities, and is well-reasoned and irrefutable to me. Thank you for the thought that was manifestly put into it, and the time to write it up and post it here.
- Paul North.
Paul_D_North_Jr Bucyrus: [snipped] Every engineer knows that even when he has a route lined up through an interlocking plant, he has to watch for, and expect that route to be taken away by a change in signal indication. . . . Taking away a route from an approaching train - also known in some places as "dropping or throwing a red in his face" - is supposed to be not allowed or prevented by the interlocking mechanism. Once an oncoming train has 'accepted' a signal indication that would permit a movement - such as by entering into an approaching block or passing a 'point of no return' - the interlocking system is supposed to prevent the signal from changing to a more restrictive aspect until either the train has left the block, or a clock/ timer has run some minutes (obviously, not a problem if the signal changes to a less restrictive aspect while the train is approaching). Unlike a highway traffic signal, the train signal can't suddenly go from yellow to red while you're still entering the intersection. Several articles have appeared in Trains over the years that are related to this, but the best explanation is in this one: "The accident that couldn't happen - collision between CB&Q and RI trains 9/25/64, Montgomery, Illinois" by Shaw, Robert B., Trains, October 1965, p. 23 (accident CB&Q Montgomery RI) Otherwise, your analysis and opinion of the facts and the NTSB's report seems to thoroughly explore all of the possibilities, and is well-reasoned and irrefutable to me. Thank you for the thought that was manifestly put into it, and the time to write it up and post it here. - Paul North.
Bucyrus: [snipped] Every engineer knows that even when he has a route lined up through an interlocking plant, he has to watch for, and expect that route to be taken away by a change in signal indication. . . .
I don't think the interlocking would prevent "dropping" a signal in front of a train. What it would prevent is changing the route (moving switch points) in front of a train until time has run down. I think the actual act of changing the signal would lock up the plant until it has "run time."
Currently, our dispatchers/control operators must ask a train if the engineer can comply with a signal being taken away. It's a bit comical when you're still 5 miles from the control point, but you're still in the block. If the engineer can comply they may drop the signal, but can't bend any switches until they know the train has stopped.
Jeff
Thank you for your comments Paul. That is an interesting point about the interlocking being capable of taking a route away once given. I don’t know if there are exceptions to this, but my understanding of interlocking plants correlates to what Jeff has mentioned above. That is, that a route can be taken away from an approaching train, but it cannot be taken away and replaced by a conflicting route. Specifically, once a train enters a plant that is lined for it, if the route is taken away, the plant locks up. This prevents a conflicting route from being lined up, which might lead to a collision course.
I did read that article in Trains about the wreck that couldn’t happen. In that case, a technical fault with the interlocking plant allowed it to grant two conflicting routes, which should normally be impossible with a properly operating plant. Wasn’t there some redesign of the track routes underway there that required a revision of the interlocking plant? I seem to recall that the technical fault accidentally introduced in that plant remodeling.
Regarding the OV-8, my point in mentioning the possible loss of a signal on approach is to address a possible argument that the engineer was momentarily distracted by the operator’s verbal highball, and that that was sufficient to miss the signal. In fact, the engineer and the fireman were both required by the rules to watch that signal from the time it came until view until the time they passed it. In this case that was a span of two minutes.
Bucyrus Therefore, this is the only explanation that I can imagine that would be directly related to the operator’s message playing a role in the wreck: When the train was four minutes from the bridge, the operator told the engineer that the route was lined for the train, and the engineer acknowledged. Because of that assurance of a lined route, before the home signal came into visual range, the engineer lost conscious free will, and remained in that condition until striking the counterweight. He either suffered a medical emergency, fell asleep, or was hypnotized by the operator’s message. At the same time, the fireman was also lacking conscious free will for some unknown reason. The only possible connection I can see between the operator’s verbal highball and the crew’s lack of conscious free will would be that the operator’s verbal highball put the engineer and fireman into a hypnotic trance. How likely is that? So overall, the investigation was willing to include the minor rules violation of the operator’s verbal highball as part of the cause without any actual proof. And yet, oddly enough, they were unwilling include, as partial cause, the fact that both the engineer and fireman had consumed alcohol while on duty prior to the accident. And yet, that too was a rules violation; arguably a far more serious rules violation than the operator’s verbal highball.
I think the operator telling them they were going to be lined up could very well have led the engine crew to let their guard down. They may have saw the approach before the home signal and figured the home signal would clear up before they reached it. Being under the influence I would think also played a part in either a full or partial loss of attention. Possibly, we'll never know, had they not been told they were going to be lined thru, they would have made more effort to remain attentive.
Reading the report, the discussions of signals being taken away is really moot. The operator never lined up the signals for them. It says the operator only verbally, over the radio, told them they would be lined. He never cleared the home signal, an eyewitness to a proceed indication on the signal not withstanding.
I've read criticisms by some people of some things that come from the NTSB. They seem to focus on some parts, while practically ignoring others. (I've read some reports where some important issues were down played.) To wit, the part the operator played, but not the part the alcohol played. They said someone under the influence indicated would have sufficient ability to avoid a collision. That's assuming they were awake and somewhat attentive. They seem not to think that impairment may lead to a dozing or hypnotic state.
Even though the operator violated the rules, the majority of the blame has to fall on the head end crew for not operating on signal indication. And they paid the ultimate price for their inattention.
Bucyrus [snipped] I did read that article in Trains about the wreck that couldn’t happen. In that case, a technical fault with the interlocking plant allowed it to grant two conflicting routes, which should normally be impossible with a properly operating plant. Wasn’t there some redesign of the track routes underway there that required a revision of the interlocking plant? I seem to recall that the technical fault accidentally introduced in that plant remodeling.
Perhaps I'm misunderstanding something, but I'm still troubled by the assertion that even after a train has 'accepted' a signal authorizing a move at some speed and is proceeding on that basis, that the signal could be changed to a more restrictive aspect without any advance warning or opportunity to brake the train in a controlled manner (other than emergency). I do agree, though, that didn't happen in this instance, so the point is moot or not applicable.
Properly, when a signal is taken down it should immediately indicate STOP. The time out clock should then be running for whatever timeout period it is set to....on most main track signals I have ever worked with, that timeout period is between 8 & 12 minutes....for the period the timer is running NO OTHER CONFLICTING ROUTE can be lined. In the operation of a Drawbridge, that would properly mean....once the signal was taken down the bridge could not be opened and no switches in the route changed until the timer has run.
Descriptions in the report, would make it seem that the Operator had never lined the signal in the first place after having told the crew that the route was lined; he then opened the bridge. Had the signal actually have been lined, he would have had to wait for the timeout to be able to line the bridge. If the signal had actually been lined and the timeout period run, the train - even not paying attention to the wayside signal would have crossed the bridge as the operator would not have been able to raise it during the timeout period.
I might add, during my career I have worked with the operator positions at this location while working with B&O interchange jobs that delivered cars to the Whisky Island interchange which locates about 15 car lengths West of the bridge.
Paul_D_North_Jr Perhaps I'm misunderstanding something, but I'm still troubled by the assertion that even after a train has 'accepted' a signal authorizing a move at some speed and is proceeding on that basis, that the signal could be changed to a more restrictive aspect without any advance warning or opportunity to brake the train in a controlled manner (other than emergency). I do agree, though, that didn't happen in this instance, so the point is moot or not applicable. - Paul North.
Never too old to have a happy childhood!
Paul,
Yes, as Jeff has mentioned, and as BaltACD has confirmed, having the signal being taken away is a moot point in that it did not actually happen in the wreck of OV-8. I did not mean to derail this thread by implying that a signal being taken away played any roll in this accident.
I only mentioned the possibility of signals being taken away in order to make a finer point about the fundamental reason why signals have to be watched continuously if they are clear. I am only trying to distinguish the degree of distraction from the lapse of attention because it is common to associate a distraction with a momentary lapse of attention. In the case of this wreck, the distraction was quite prolonged, as opposed to being momentary.
In this case, the home signal was not clear, but the crew must have assumed it was clear if they were conscious and under the influence of the operator’s message. So even if a remark from the operator caused the crew to have a lapse of attention, that lapse needed to be at least two minutes long. That was the time required for the crew to watch the home signal if they believed it was clear.
Regarding the issue of having no warning if a clear home signal is taken away: When a train approaches an interlocking with the route lined for it, it is possible to drop a red board in the engineer’s face. If that happens, the engineer may not be able to stop for the signal or even for the conflicting route, but he must make every effort to do so. Whether that would require stopping as quickly as possible, I am not sure. Perhaps it does because I suppose one way a route could be taken away from an approaching train would be for a conflicting train to run its red home signal and enter a conflicting route. So dynamiting the train that lost the route might prevent a collision if a conflicting train has run its stop signal.
Not only might the operator accidentally drop a red board against an approaching train after having lined up the route, but also some extenuating circumstance may compel the operator to do it intentionally. And then there is always the possibility of a broken rail or other type of signal fault that can take the route away from a train on approach.
Bucyrus Regarding the issue of having no warning if a clear home signal is taken away: When a train approaches an interlocking with the route lined for it, it is possible to drop a red board in the engineer’s face. If that happens, the engineer may not be able to stop for the signal or even for the conflicting route, but he must make every effort to do so. Whether that would require stopping as quickly as possible, I am not sure. Perhaps it does because I suppose one way a route could be taken away from an approaching train would be for a conflicting train to run its red home signal and enter a conflicting route. So dynamiting the train that lost the route might prevent a collision if a conflicting train has run its stop signal.
What made this incident memorable for me was that I watched the entire derailment happen. I was driving west on Hwy 20, and saw the locomotives go under the bridge just as I was approaching the turn for the frontage road, so naturally I turned off to watch the train go by. As I approached the crossing on the frontage road, I saw the show begin. It looked like a slow-motion ballet of wreckage as it happened. If I had been just a few seconds quicker, I would have been right at the crossing, which would have been not so good for me, as the crossing was buried in wrecked freight cars, and I would have been at the bottom of the pile.
To this day, you can still see traces of damage on the northernmost bridge support on the west side of the tracks, where a boxcar had wrapped itself partially around the pillar.
Instructions on my carrier are, when getting a 'unexpected' Stop Signal, DO NOT put the train in Emergency. Make a maximum service reduction to stop the train. Uncontrolled slack action is a big derailment cause.
zardoz That very scenario happened back in 1969 at Waxdale (Racine) WI. A college-educated idiot of a Trainmaster decided to do an efficiency test at the automatic interlocking on a southbound CNW train. The train had a clear on the distant signal to the interlocking, but after the train passed the signal, the Trainmaster pulled a fuse to drop the home signal to red. What that idiot didn't understand was that the southbound train was running at track speed (50 at that time), and that there was a curve not too far from the interlocking which prevented the engineer from seeing the signal. So when the engineer came around the curve and saw the red, he immediately plugged the train. Unfortunately, the slack ran in while the train was going around the curve; the buff forces caused the train to derail, spilling about 25 cars onto the right-of-way.
I've had a few control points drop right in front of me. (Unintentional glitches) We too are told in those circumstances to just bring them to a stop, "consistant with good train handling techniques."
Just tonight they were having signal problems at a control point. The dispatcher warned approaching trains that they may lose a signal, and if they did to just bring it to an easy stop and give him a call.
Ultimately, this investigation blames the death of the engineer and fireman on the bridge operator. The investigators state as unequivocal fact that, “the radio conversation caused the engineer to disregard the visual wayside indications.” And, yet their only evidence of this is that it could have occurred.
So, what the investigators have concluded is that because the verbal message from the operator came first, it was the act that set the events of the accident into motion. The investigation nearly forgives the engineer because he merely acted on false information from the operator.
And yet, the investigation found the engineer to have a blood alcohol level that is very near the point where it is illegal to drive a car. And this was a B.A.C. level was tested after the engineer’s body was removed from the wreckage of the cab, which probably took significant time. That time may have diminished the B.A.C. measurement from where it was at the time the engineer failed to respond to wayside signals. Moreover, the report asserts that both the engineer and fireman consumed alcohol while on duty the day of the accident.
It should be noted that the operator’s behavior in this matter, while a rules violation, did not arise from carelessness, lack of attention, indifference, impairment, dishonesty, recklessness, ill will, laziness, or malice, as is often the case with a rules violation. The company gave the employees radios and told them to use them to improve transportation. In his own mind, the operator was going beyond the call of duty to help the engineer of the train get it over the road. He was using the radio to “improve transportation.”
But the operator did make a mistake by breaking a rule that forbade the use of the radio to control train movements. And he seemed to have committed a greater error by not informing the crew that he had changed his mind, and was not going to have the route lined up for them.
That is perhaps the hardest action to understand. But was it really an error? He knew that the signals were the overriding authority, so logically; there would be no need to tell the crew that the signals would not be clear. He used the radio to improve transportation. Using the radio to tell the crew that the route would not be clear would do nothing to improve transportation. It is fairly easy to see that reasoning in the mind of a logical man.
Maybe he failed to inform the crew that he had rescinded his advice about the route being clear simply because he forgot. But that could not have been a rules violation since the creation of the subject of the retraction was against the rules in the first place.
In any case, whatever the reasons for the operator’s actions were, the actions per se do not explain the cause of this wreck, and they may not have been even connected to the cause. It may be true, as some have suggested, that the NTSB is free to speculate and use the experience of their best judgment in accident investigations. But to state as fact that the actions of one man directly caused the death of two other men without any proof strikes me as a supreme injustice.
Do not discount the ability of T&E crews to mistake communications as 'authority to pass a stop signal'.
A couple if nights ago we had a crew come on duty, board their train which was stopped facing a correctly displayed Stop Signal and operate by that Stop signal when they were told that 'when they could be moved' they had authority by a restriction that existed a couple of miles beyond the Absolute Signal. Crew mistook that verbal authority as authority to pass the Absolute Stop Signal - when the procedures to pass a Absolute Stop Signal are very involved and specific when issued by the Train Dispatcher. Review of the full radio communications between the crew and the Train Dispatcher revealed that at NO TIME did the Train Dispatcher give the crew authority to pass the Stop Signal
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