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Good evening, watching the evening news and NS has had a derailment around 3:30 this afternoon.

The accident happened in Westmoreland County.

Looks like a east bound train was involved along with a west bound double stack.

It was reported no injury's to the train crew, which is great news.

 

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mlavender480 posted:

Westbound empty oil train Z7X rear-ended stack train 21V, which then derailed into eastbound 20Q.  No injuries reported.  It happened at about MP 319 on the Pittsburgh Line.

It will be interesting to read the accident report.  I find it difficult to understand how a train can run into the rear of another with today's technology.  Did the train run a red signal?  This rail line must not have positive train control installed or the technology failed.  NH Joe

 

It has had PTC since this past summer.  Now; whether the oil train was operating with PTC operational or cut out probably wouldn’t have mattered.  As with the CSX accident in Ohio this past summer; PTC essentially doesn’t do anything when a train is operating at restricting speed as is likely with the empty “oil cans” yesterday.  

And this last assumes the signal system was functioning properly.  There was a post on Train Orders last night indicating crews had been reporting signal problems through this area in recent weeks.

Curt

New Haven Joe posted:
mlavender480 posted:

Westbound empty oil train Z7X rear-ended stack train 21V, which then derailed into eastbound 20Q.  No injuries reported.  It happened at about MP 319 on the Pittsburgh Line.

It will be interesting to read the accident report.  I find it difficult to understand how a train can run into the rear of another with today's technology.

Everyone seems to overlook just exactly what "restricted speed" really is. Once a signal displaying "Restricting", is passed, the Engineer must be prepared to stop within one half the distance of his/her visibility, but not to exceed 15/20 MPH (depending on the specific railroad). Crews not following the rules tends to result in such "rear-enders".

 Did the train run a red signal?  

No. The train that rear-ended the first train, was running on  "Restricting" signal.

This rail line must not have positive train control installed or the technology failed.  

Positive Train Control would NOT have prevented such a collision.

NH Joe

 

 

I think the “fatal flaw” in the PTC system is that is lulls the crew into a false sense of security. It’s human nature to think that if PTC has everything covered, I don’t really need to pay attention to the line side signals, or keep up with situational awareness regarding other trains near me. If there’s a problem, PTC will alert me to anything and keep me out of trouble. Not always.

The dumbing down of a once great industry continues...

Rich Melvin posted:

I think the “fatal flaw” in the PTC system is that is lulls the crew into a false sense of security. It’s human nature to think that if PTC has everything covered, I don’t really need to pay attention to the line side signals, or keep up with situational awareness regarding other trains near me. If there’s a problem, PTC will alert me to anything and keep me out of trouble. Not always.

The dumbing down of a once great industry continues...

Not to mention GE's "Trip Optimizer" and similar locomotive autopilot type control systems which, when engaged, essentially takes the throttle out of the engineer's hands......

Reliable sources tell me that the preliminary cause is the empty tank train crew failed to fully comply with conditions required when operating on a Restricting signal indication and restricted speed. Impact was at 16 mph.  Restricted Speed on NS operated property is defined as  "A speed that will permit stopping within one-half the range of vision, short of train,................but not exceeding 20 MPH" 

C.J.

Last edited by GP40
GP 40 posted:

Reliable sources tell me that the preliminary cause is the empty tank train crew failed to fully comply with conditions required when operating on a Restricting signal indication and restricted speed. Impact was at 16 mph.  

C.J.

And there you have it! Failure to control your speed in order to be able to stop within half the distance of your visibility.

Dominic Mazoch posted:

Correct me if I am wrong.  PTC would not have stopped the train running at Restricted Speed? 

Correct. Plus, PTC has no real idea of what is ahead of you, as it depends on track circuits (pretty much just like signal systems), and thus has no idea where the rear end go the train ahead is (at least until the new/future FRED units begin to transmit that information).

OK, the engineer was not operating the train according to the rules. 

Correct again.

And I agree, one should not fully depend on PTC to get one out of trouble.  But if PTC cannot stop a train running RS, then what other safety issues are out there with this system?

None that I'm aware of. The proper compliance with the "Restricted Speed" rules has always been EXTREMELY important. Apparently the newer generation of operating crews are depending WAY TOO MUCH on the technology? 

 

So, in terms of operations at restricted speed, are trains operating too slowly for PTC to kick in? Or is the signal aspect set differently and thus PTC dosen't kick in? My understanding is that PTC is supposed to activate the breaks if a signal is past at red.

Here’s another question: what are the features of the North American cab that make it safer, precisely? Is it that the wider cab spreads out the impact force more? Or is it because it is isolated?

No one technology is a panacea, the danger is always present. Sadly most rulebooks are written in blood.

Norm posted:

I drove over to check it out yesterday.  The derailment was  3 miles east of Greensburg.

We also had a pedestrian fatality yesterday.  A person was struck and killed at our Station Square area in Pittsburgh.

Norm

Thanks for the precise location and sorry to hear about the death. I'm always somewhat mystified by pedestrians being hit by trains. Trains are really quite large and have flashing lights and REALLY noisy horns. 

Redshirt214 posted:

So, in terms of operations at restricted speed, are trains operating too slowly for PTC to kick in?

No, that's not the issue in play here. The problem in this situation is that even if the PTC system was active and working, it could not know where the REAR of the preceding train is. The system has to rely on the ENGINEER (remember him?) to comply with RESTRICTED SPEED operating rules.

What exactly is "Restricted Speed?" It is a speed not to exceed 15 or 20 mph (depending on the railroad) that will allow an engineer to stop his train within half the range of vision. How far is that? It depends. I have run trains in fog where the visibility was only about 400 feet. That required me to run at walking speed in order to be able to stop within half the range of my vision.

The same holds true on a curve. If you are running a long straight stretch of track under restricted speed and you can see a mile ahead of you, then 15 or 20 mph is fine. But when you get to a curve that is lined with trees on both sides of the track, what  do you do? You may only be able to see 5 or 10 car lengths ahead of you in the curve. If you can only see 5 car lengths ahead of you, you have to be able to stop in 2-1/2 car lengths! 15 mph in that situation ain't gonna cut it. 2 or 3 mph would be about right for 5 cars visibility ahead.

...My understanding is that PTC is supposed to activate the breaks if a signal is past at red.

The train did not pass a RED signal. It passed a RESTRICTING signal. There is a difference. The brakes (not "breaks") would not automatically apply when passing a Restricting signal because the Restricting aspect does not require you to stop.

Last edited by Rich Melvin

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