Northeast Regional 188 - Accident In Philadelphia

litz wrote:Specs on the sprinter available online seem to indicate about 150 seconds to take an 8 car train from 0 to 125 ...

Based on that, my "back of the envelope" math says it's marginally possible to make that acceleration point in the time and distance available after coming out from the speed zone ... really depends on the actual real-life distance and time figures ...

He would have to have been accelerating TO speed, however, at the time he went into emergency prior to the derailment ... and not been AT speed (and maintaining that speed) ...

If he was AT that 100+ speed, and maintaining it ... if I understand things correctly, that train would have to have been blasting through either an 80mph zone ... in an area with actual speed controls in place. Which shouldn't be possible.

(all theory and speculation, of course)

ACSES ("true" speed control/PTC) is NOT in service in this portion of track. There is no speed enforcement other than what may have been kludged together by the cab signal system.

I am not qualified on any portion of NEC, and I will happily defer to advice or corrections made by others. That said: I have been made to understand that certain speed restrictions are enforced by the "old" cab signal system, thru code-line drops. Old cab signal system is only equipped to enforce "normal", "limited", "medium", and "restricted" speeds: that is to say, respectively: MAS, 45, 30, 20-max-prepared-to-stop. And the only way in the engine cab to forestall cab signal penalty is to go right to "suppression" - between 15 and 30 psi of brake pipe reduction, depending on configuration of brake stand. In any event, it is a big wad of air, and it will slow a short passenger train "right now".

Prior to ACSES, certain high-profile civil speed limits were enforced by coded cab signal drops (limited to the above four speed options) - the "closest" speed to what was desired might have been chosen; or else, code zones were strategically placed to enforce "some" braking, but to allow it to let go after a certain "safe" distance, ensuring speed compliance at the permanent restriction.

As was stated earlier in this thread; a cab drop was evidently in place for WWD trains prior to the wreck curve, but such was not in place for EWD trains.

boomer wrote:This incident will be the poster child for more rapid deployment of positive train control.

188's engineer might be become this generation's Ricky Gates, much as the latter resulting in major drug policy changes.

PTC would obviously prevent the type of accident that this seems to have been and prevention is obviously the best solution.
however talk so far in the thread about designing for future crash-proof design has concentrated on the cars. How about designing catenery posts to shear at ground level in this type of impact? There's certainly been a move towards this design for posts for road signs. Obviously it wouldn't be a fast process, with the lifespan of the PRR posts being what it is.

Noel Weaver wrote:I'm going to make this pretty short. The fact that there were not many more fatalities than there were I think says something about the design of this equipment.
Noel Weaver

7 fatalities is still more than there should have been. If the design was so superior, why were there more than 80% injury rate? Over 200 of the 243 riders of the train had to go to the hospital or get medical treatment from the emergency medial technicians. 200/243 = 82.3%
How many riders were injured by airborne missiles caused by other riders or by luggage? A better designed railcar should be able to significantly reduce the number of flying missiles - I realize it will be impossible to eliminate all of them. How about some netting to keep the baggage in the racks, or enclosed racks with doors like we see on jetliners?

Let's not get lost in the idea that there aren't any improvements that could reduce the number and severity of the injuries because there was a relatively low fatality rate.

boomer wrote:It is believed that the engineer thought he was elsewhere along the route. How he became unaware of exactly where he was can only be guessed at this point. More details will obviously become available in time.

I've often wondered about this. Rail ROWs have no lighting and minimal signage, compared to a traditional highway. It seems like something that could happen pretty easily at night? I know I've had it happen to me driving on the highway at night some times, and even riding my bike at night. It certainly seems plausible? Any engineers here want to chime in on this specific subtopic? I'd be curious to hear.

If he thought he was clear of the Frankford curve and into 110 mph territory, then that begs the question, would the cab signal system allow him to accelerate to 100+ mph? The prior posts seem to indicate that he should have been held to 80 at least until that .3 mile stretch before the curve. Hope there's no issue with the ACS-64's in any case!

I am thinking many people don't realize that there are two whole catenary H towers out of action, one having been totally destroyed and on the ground & the other partially collapsed with the cross beam propping it up. The news was not at all mentioning the towers, just that the wires are down. Does amtrak have materials on hand to rebuild these? How long will it take? Surely concrete foundations take time to cure before they can put any kind of tension on the wires? It is on a curve after all...

And what of the signal system? Even if the wires are re-mounted to the undamaged towers and trains could pass, would they not need some form of signal system and power for it?

Has anyone noticed the amount of arching that took place in the surveillance video after the passing of the train? It seems to insinuate that there could possibly have been more going on then simply striking a total of two catenary poles. I'm wondering at what point did the arching start in the video relative to where the train came to rest? Seems that the wires might have already started to be yanked down by the locomotive that was leaning heavily onto one side. If that was the case, it was a miracle that the train didn't impact several more poles along the way before coming to a complete stop.

Like I said in my earlier post, the pics reminded me very much of the derailment in Spain, and had speed written all over it. The two accidents will be remarkably similar. What made the crash in Spain so tragic was that indeed the train derailed right into an embankment holding up an over pass. Had that not been there, maybe the amount of fatalities could have been considerably less. My parents being Spaniards, I have been in Spain many times, and have traveled on numerous Talgos, and from my most recent trip, the construction of the cars did NOT at all appear to be anywhere as sturdy as an Budd Amfleet coach or even a NYC subway car at best. Talgos were designed for speed with a very low profile designed to significantly reduce the center of gravity. HS trains like the TGV, ICE, and Talgos are light weight in nature and are not designed to be tanks as some might think. That being said, the false impression of what is perceived to be built like a tank needs to be addressed here. I was always under the impression that the M7's on the LIRR and MNR were quite tank like. Then the accident at Valhalla shot that notion out. But then again, did the FRA and NTSB imagine having the third rail pierce a rail car from underneath? Most likely not. Likewise, when Budd designed the Amfleet cars, they wanted it to be able to withstand certain levels of impact, but I'm quite sure that there is only so much you could incorporate into a rail car that would protect it from a steel catenary or rail piercing it at speeds of over 100mph. Unfortunately, the brute physics involved in a rail accident are extreme, and quite frankly, you will not ever have a 100% safe design able to withstand every type of impact that can occur. I actually am one who wondered as well, how would have an Acela faired in this accident? It could have very well done worse, or better, who knows. But derailing at 100mph+ on any type of train will most likely yield disastrous consequences.

On a side note, someone asked here if it is possible for an engineer to become suddenly disoriented? Absolutely. In fact, anyone driving a car could suddenly be disoriented. It happens. Could be as a result of being sleepy, or preoccupied with either thought or sadly as it happens these days, our cell phones. I have had 2 occasions where I became disoriented when my stress level jumped to max level. At this point, everybody will speculate as to what happened, but the NTSB will eventually determine whether it was human error or mechanical.

There was talk also about speed control, and why didn't the speed control reduce the train's speed before the curve. As mentioned by a few, speed control does NOT always control permanent speed restrictions. The particular RR has to set it up that way, and many will be surprised to know that on many RR's that do have speed control in place, will have many of it's speed restricted areas unprotected. Such as an example, on the LIRR, the curve on the mainline located just east of woodside, has a speed restriction, If memory serves me, at 55mph. However, the mainline beginning from end of the curve east to Kew Gardens is MAS 80 MPH. when west bounds approach this curve, the speed control will still read 80MPH, but engineers are required to know EVERY speed restriction on the entire property. Therefore, all west bounds will begin to reduce their speed to the required limit before entering the curve even though the cab signal will still read 80MPH. But on other parts of the RR, such as the curve located east of Lynbrook station, the cab signal will drop to 60MPH matching the permanent speed limit through this stretch of RR. The technology already has existed for many years but RR's can not apply this feature into every location where there is a speed limit simply because of the extreme cost associated with it. I don't know how Frankford junction is set up, but by what many say here, it sounds like we have a situation like what we have by Woodside. So obeying the speed limit in that location falls squarely on the engineer.

electricron wrote:

Noel Weaver wrote:I'm going to make this pretty short. The fact that there were not many more fatalities than there were I think says something about the design of this equipment.
Noel Weaver

7 fatalities is still more than there should have been. If the design was so superior, why were there more than 80% injury rate? Over 200 of the 243 riders of the train had to go to the hospital or get medical treatment from the emergency medial technicians. 200/243 = 82.3%
How many riders were injured by airborne missiles caused by other riders or by luggage? A better designed railcar should be able to significantly reduce the number of flying missiles - I realize it will be impossible to eliminate all of them. How about some netting to keep the baggage in the racks, or enclosed racks with doors like we see on jetliners?

Let's not get lost in the idea that there aren't any improvements that could reduce the number and severity of the injuries because there was a relatively low fatality rate.

How many passengers were buckled in? There is a reason why airlines recommend you stay buckled in while in your seat.

Is that going to be a suggestion / requirement on Amtrak now?

SCB2525 wrote:The MAS doesn't increase to 110 just before the curve; it's 80 Clearfield to Shore (2&3) then 50 at the curve, but that 0.3mi section preceding the curve is not cab signal enforced below 110.

There was someone on TV last night who suggested that there is a switch in the cab which allows the engineer can turn off the cab signaling system, but it wasn't clear why one would do this unless it just wasn't working properly.

Regarding the discussion of safety design, I think we've had enough right now. That will all come out in the investigation. It's a bit premature right now. Let's give it a short rest. It is related, of course, e.g. as to how it performed. I think some of the comparisons have been a little far afield. At this point, we know the speed, and the capabilities and characteristics of the track in the area, and see the damage. More forensic analysis will surely be forthcoming.

AlexC wrote: How many passengers were buckled in? There is a reason why airlines recommend you stay buckled in while in your seat.

Is that going to be a suggestion / requirement on Amtrak now?

There are no seat belts on trains...

mark777 wrote:Has anyone noticed the amount of arching that took place in the surveillance video after the passing of the train? It seems to insinuate that there could possibly have been more going on then simply striking a total of two catenary poles. I'm wondering at what point did the arching start in the video relative to where the train came to rest? Seems that the wires might have already started to be yanked down by the locomotive that was leaning heavily onto one side. If that was the case, it was a miracle that the train didn't impact several more poles along the way before coming to a complete stop.

The wreck took down the wire over all four tracks; and, if the PRR-installed catenary is the same as the NYNH&H-installed catenary that I'm more familiar with, taking out an entire catenary structure will also rip down at least one high-voltage transmission tower attached to the structure. That would explain why there is so much arcing.