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prrjim posted:

Well, the header for this thread is somewhat misleading like the journalists.   the Amtrak train did not derail and kill two people in the process.      The guys on the backhoe drove in front of the Amtrak train and caused the derailment, and were killed in the process.    

Are we starting to split hairs????

It was Amtrak.

Train did derail.

Two people were killed.

It was just outside Philly.

??? thread header pretty close in my book.

I do not know the rules for Amtrak, but I do for CSX. That was a very small work zone, minimal amount of people. IF MEN and EQUIPMENT are in the clear, then there is not harm. Dusty, probably with this type of work. With that distance traveled, and at the amount of work being done over that distance, your minutes lost, would turn into hours lost. 

With PTC in place in some areas, and ERAD, you can not make up time, without getting into a heap of trouble and possible fines.  

Rules may change, and that should not happen. Why make more rules, when the ones in effect are not being followed. We had a case where a train got by a red signal. Everyone, including the union thought and said the red signal was hard to read and could have been mistakenn for another signal. Several in a row.  Fact was, this was an experienced engineer, been over that line several thousand times. He did not obey the signal 1.5 miles back that told him he would have a red signal. Even with the rules stating he and the conductor, had to communicate each signal aspect and announce on the radio what the signal was. Again, why change them, when the rules in place will save them.

NTSB, will release findings. I feel for all families involved on the RR. Something that will live with them forever. Been there, done that, and it scars you.

Gene posted:

With PTC in place in some areas, and ERAD, you can not make up time, without getting into a heap of trouble and possible fines.  scars you.

This just shows that PTC isn't the end-all-be-all answer to safety. No computer or comm channel will keep you from smashing into something that just got onto the rails that the hogger had no way to know was there. Especially at those speeds.

Gene posted:

PTC was not designed for that. It takes the human error out of controlling a train with the signals, and rules. That, when implemented will do that. Nothing else. 

 

Yeah, I know that but I know of people in the industry who apparently don't. I keep hearing about PTC as the end of every problem they'll ever have, which happens with companies. People like to think that the new process will solve everything...

I understand what AMC Dave is trying to get across to us. The headline is ambiguous, and lets the reader draw an incorrect conclusion as to the cause and effect.  It should have read "Construction equipment on track causes derailment of Amtrak train and deaths of two workers."  But most reporters have the "advantage" of a public school education (Motto: "Just send 'em through and let society set them straight later."

Every day in the NYC area, traffic reporters say that "a commercial truck 'wandered onto' a parkway." (our local system of parkways has very low clearances).  Really? The truck "wandered"?  The driver had nothing to do with it?

Nearly every day, one can hear minor and major gaffs in news reporting.  Here's a recent example: Dale Earnhardt is reported as admitting that he has had at least 5 concussions over the length of his career as a race car driver. In order to help scientists understand the effects of concussions, "He plans to donate his brain, posthumously, for research."  Really??? He's not willing to donate it while he's still alive???

 

Last edited by Arthur P. Bloom
jim pastorius posted:

The Wall Street Journal is saying that a basic safety rule was violated by not putting in a "shunt" ??  Is this a signal  piece or track ??  I don't subscribe so couldn't access the whole story. Anyone know ??

Sounds to me like a" lock" a train dispatcher might put on his  signal panel upon issuing work permits. Just my opinion not  a fact.

Jim, I don't know what a "Shunt" would look like, but the purpose of a shunt, would be to provide an electrical path from one rail to the other, so the signal system would detect the presence of the equipment on the track.

 Hirail vehicles typically have a wiper or contact system to provide a good shunt, because of the light weight of the vehicles, and limited contact surfaces of the Hirail vehicle's wheels. with a train, there is more weight to help insure a better wheel/rail contact, and so many more axles to shunt the electrical current, that there is rarely a problem with electrical continuity.

 A portable shunt could be as simple as a rigid bar, or a cable with rail clamps at each end to allow an electrical path between the rails.

Doug

Some are straight DC. Some are, for lack of a better term, pulsating. That is, they are transmitted from one end of the block at a very slow oscillation, and the relay at the other end of the block is part of a tuned circuit.  The way it works, in very simple terms, is the relay coil / capacitor circuit will operate and stay operated as long as the transmitted frequency is continuously received.  A tuned circuit of this type will send a pulse to a relay that is "slow release." The relay circuit is designed to drop after a certain (short) time period.  Just as it is about to drop, another pulse is transmitted. As long as the pulses are received during the correct time cadence, the relay stays operated.  Any change in the track circuit, which consists of the rails, line wires and relay, such as an open circuit (broken rail or wire,) or a shunt (caused by wheels or a foreign short circuit in the wires) will cause the relay to drop and its N/C contacts will activate whatever device is designed to operate.

Here's an example of how it DIDN'T work, to illustrate the concept:  The Amtrak crash at Big Bayou Canot in 1993 could have been prevented, or at least rendered a lot less serious, had there been break-away joints in the track where it crossed the bridge. The boat whacked the bridge out of alignment, but the continuous rails just bent, rather than breaking. (They were continuous because the swing bridge had been taken out of service permanently and had been bolted/welded shut.) Had the the rails broken, a track circuit would have detected the problem, and POSSIBLY alerted the crew to stop in time.  It's easy for us arm-chair electrical engineers to second guess the railway management, but it seems a very simple concept that might have saved some lives. 

This is a very basic explanation, and I have left out some other info, so I suggest that you read up some entries on-line that describe the concept in more detail.

(PS:  I enjoy your tag line. However, I live in the Serene Socialist Peoples' State of Nueva Yok, where we do NOT enjoy the protection of the 2nd Amendment. It has been rescinded by Our Supreme Leader, Comrade Governor Cuomo.) 

Last edited by Arthur P. Bloom

Thank You again Arthur, I was aware of shunting and open circuit detection, but I learned more than I already knew.

I appreciate your reply. I wasn't aware of break away joints near bridges, but once mentioned, the idea makes perfect sense.

It is a shame that break away joints weren't used on the Big Bayou Canot bridge, sadly many lives may have been saved, but there is that old hindsight is 20/20 issue.

Doug

The machine shown mostly was the Loram Ballast cleaner. The Backhoe was strewn in pieces all along the ROW. 

Arthur P Bloom. Your description about track shunting is good. The only thing I took exception to is not all broken rails will drop a track circuit. There are several areas that are dead areas. I can remove the rail and the circuit stays up. Also a broken rail in the summer time may not drop the circuit either.

The Big Bayou accident was a freak accident. The track and signals worked as designed. The only was it could have been prevented was all in the hands of the boat captain and his employer, not CSX. If you really think break away joints needed to be there, then what at the Dodge City derailment?

     Seeing as the news media must continue to confuse things, I have reconsidered my position about waiting on the NTSB.
     My dad is a rail-transit consultant. One of his coworkers worked on Amtrak PTC and, as a result, has connections at CTEC.
    As my dad was told, initially both tracks were out of service. The fault is with the MOW crew's foreman, who gave permission to the dispatcher to put the one track back in service without first making sure that his crew was clear of it.

Last edited by spwills

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