ruderunnerTimeline question, so Sperry found the defect roughly 24 hours prior to the derailment. How quickly did Sperry inform CSX of the track problem? Did CSX track crews/dispatchers get the warning in time to have stopped the train? Or did the track report show up the next morning?
As I understand it, the defect that caused the derailment was found the day before the derailment. It was then scheduled for replacement to take place two days later. However, derailment occurred one day later.
From this, I must assume that CSX was informed of the defect one day before the derailment by virtue of the fact that the repair work was scheduled at that time. I also assume that the defect did not require the immediate halting of train traffic and repair, and that the repair being scheduled for two days later was within the rules. Apparently, the derailment proved that the rules were defective.
This is part of why I want a more exact accounting of all the defects and all the times and actions in a coherent framework. The first question I would ask is 'which defect do you mean' out of the several that were there... the reverse detail fracture not being critical enough to 'flag' by even the RSAC revised guidelines (it being out of the rolling-contact failure zone the guidelines concerned, but the 20% transverse fracture definitely being).
What I think went on here was: there was a bad piece of rail in a track that was not as heavily used by intent as the 'other main'. There were several defects here, one of which was actionable and about to incur a remediation procedure when the decision was made to replace the whole affected section of rail directly rather than put on a 'patch'. That was scheduled more or less 'right away' but there was a lag associated with the time to deliver the new rail to the place and coordinate the (larger and different, perhaps) crew that would do rail replacement rather than field welding. That lag was approximately two days, and in that time the UNRELATED reverse-detail fracture went abruptly from 5% to 100%, perhaps entirely under the train (since we have neither a definition of what 'slight' meant to the investigators nor a picture of the 'batter' involved, even assuming the reference is to the reverse-detail fracture edges) and caused the reported wheel damage and then derailment.
What I want to see is the timeline of actions and priorities that the various people involved at CSX did, and see if there are other interpretations or areas where valid 'better policies' or improvements could be made.
Wizlish The thing is that the fundamental ambiguities are being augmented, not reduced, when you confuse the cause of the accident with one of the ambiguities that were confused in the report. My complaint is not about the number of words so much as it is all the words that only contribute to the confusion, and require more work to extract the point than was needed to comprehend the situation before the post was made. My apologies too, because this is not about words or posts or even that there are 'ambiguities' (I think they are in some places actual errors) - it is about figuring out where the actual problem was, and whether there are better ways to act to prevent recurrences in the real world. A simple observation that the RSAC committee's revised methodology 'would have prevented this accident' is simply wrong, as I think I have demonstrated, because the actual break that caused the failure was not in the RCC zone that methodology 'flagged' for more prompt response. What is needed (and by default provided, I think, in the CSX response mentioned in the Richmond paper's article) is increased attention to other potentially critical failures -- reverse detail fractures, in particular -- and a better set of procedures to check for these and respond to them appropriately, if that is possible.
The thing is that the fundamental ambiguities are being augmented, not reduced, when you confuse the cause of the accident with one of the ambiguities that were confused in the report.
My complaint is not about the number of words so much as it is all the words that only contribute to the confusion, and require more work to extract the point than was needed to comprehend the situation before the post was made.
My apologies too, because this is not about words or posts or even that there are 'ambiguities' (I think they are in some places actual errors) - it is about figuring out where the actual problem was, and whether there are better ways to act to prevent recurrences in the real world. A simple observation that the RSAC committee's revised methodology 'would have prevented this accident' is simply wrong, as I think I have demonstrated, because the actual break that caused the failure was not in the RCC zone that methodology 'flagged' for more prompt response. What is needed (and by default provided, I think, in the CSX response mentioned in the Richmond paper's article) is increased attention to other potentially critical failures -- reverse detail fractures, in particular -- and a better set of procedures to check for these and respond to them appropriately, if that is possible.
Timeline question, so Sperry found the defect roughly 24 hours prior to the derailment. How quickly did Sperry inform CSX of the track problem? Did CSX track crews/dispatchers get the warning in time to have stopped the train? Or did the track report show up the next morning?
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Wizlish Euclid Finally, the report states that said ultrasonic testing found a 20% reverse detail fracture, but does not say where this was located, or whether it had anything to do with the one or two (unclear which) defects found near the point of derailment. You're not doing your job right. The 20% was a transverse fracture, not a reverse-detail fracture. This may look like a jargon difference to you, but it is assuredly not to people who understand rail failure. For heaven's sake stop using all those words and just make the points. (And I speak as someone who uses far too many words most of the time.)
Euclid Finally, the report states that said ultrasonic testing found a 20% reverse detail fracture, but does not say where this was located, or whether it had anything to do with the one or two (unclear which) defects found near the point of derailment.
You're not doing your job right.
The 20% was a transverse fracture, not a reverse-detail fracture. This may look like a jargon difference to you, but it is assuredly not to people who understand rail failure.
For heaven's sake stop using all those words and just make the points. (And I speak as someone who uses far too many words most of the time.)
tree68It would be imprecise at best. By the time the crew says to themselves, "boy, that was rough," and reacts by hitting the "mark this spot" button, they may well be a significant distance beyond the actual location, especially at higher speeds.
The reason for using a 'separate color' is that the responding crew would know that the defect would be displaced a distance corresponding to reaction time and (reported) train speed back from the point marked, rather than close to the site as the Sperry-car marks are. The direction would be inferred from which 'side' has the marked rail. And yes, the thing would have to be maintained, and Murphy or Finagle would ensure some problem in an actual accident situation, but it's not that complex a set of requirements; a glorified paint spray can with long nozzle is really all it would take.
Not that I'm actually advocating it, but it would be one added thing simplifying a track car crew's realtime work 'process'.
EuclidFinally, the report states that said ultrasonic testing found a 20% reverse detail fracture, but does not say where this was located, or whether it had anything to do with the one or two (unclear which) defects found near the point of derailment.
This is one of the important details that needs to be distinguished in that '40 feet' - one of the critical reasons in my opinion that the decision (a major proximate cause of the accident, as things turned out) to replace the whole piece of rail as defective rather than field-welding the defects was taken.
The 20% was a transverse fracture, not a reverse-detail fracture. This may look like a jargon difference to you, but it is assuredly not to people who understand rail failure. I will leave it up to experts like mudchicken to explain this in more credible terms, but the transverse fracture observed WAS in the rolling-contact fatigue zone, and it was at 'actionable' extent. It was also NOT the defect that proceeded to failure to cause the accident.
1) The first is a break in the railhead.
2) The second is an in-service rail failure found in January 2014.
3) Item #1 was 30 inches east of item #2.
WizlishLeads me to wonder -- tongue only partly in cheek -- whether there ought to be some apparatus on the engine that can mark the rail with a different color than that used for any of the Sperry cars, to identify the precise location of an issue and perhaps allow recognition as a complication or new problem among perhaps-already-recognized issues even before the MoW people can get there to check things.
It would be imprecise at best. By the time the crew says to themselves, "boy, that was rough," and reacts by hitting the "mark this spot" button, they may well be a significant distance beyond the actual location, especially at higher speeds.
On the other hand, their knowledge of their territory can lead to a more precise location, both by milepost and perhaps a physical characteristic. Odds are the restriction would be for the next nearest mileposts in both directions anyhow, at least until something more specific is found.
Then we get into maintenance of the marking devices...
NORAC defines restricted speed as already noted, but with a limit of 20 MPH. We use 20 MPH on the main, but 10 MPH in "Rule 98" by timetable rule.
Remember, too, that a 5% crack may not "register" with the crew at all. Even a completely broken rail, if still properly secured, may pass unnoticed. And speed can make a difference. Track that is downright nasty at 15 MPH may seem relatively smooth at 40 MPH. Been there.
This is why track is regularly patrolled, and inspected with devices like the Sperry cars.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Wizlish BaltACD Current procedures - Crew reports track anomally - Dispatcher puts out Restricted Speed Slow Order for the location of the anomally, automatically - The location of the anomally gets reported to MofW for inspection. After inspection, MofW will change the slow order as they see fit, or take the track out of service. Does the dispatcher have some idea of how serious a 'track anomaly' is from the description he gets and the questions he subsequently asks?
BaltACD Current procedures - Crew reports track anomally - Dispatcher puts out Restricted Speed Slow Order for the location of the anomally, automatically - The location of the anomally gets reported to MofW for inspection. After inspection, MofW will change the slow order as they see fit, or take the track out of service.
Does the dispatcher have some idea of how serious a 'track anomaly' is from the description he gets and the questions he subsequently asks?
When the crew mentions 'rough track' - that is all that is needed to issue a Restricted Speed train messages until the track is inspected. Dispatchers are not qualified to make decisions on how serious a track situation is - that is what MofW personnel are trained for. The ONLY thing the Dispatcher needs to know is that the train crew took exception to the track quality at a specific point - the rest is up to MofW. Train crews don't necessarily know that track has been Sperry inspected or when the inspection occurred, nor do they really care - it isn't their job.
Remember the requirements of Restricted Speed - 'proceed at a speed that will permit stopping short of obstructions or track anomallys, within 1/2 the range of vision, not exceeding 15 MPH'.
Never too old to have a happy childhood!
BaltACDCurrent procedures - Crew reports track anomally - Dispatcher puts out Restricted Speed Slow Order for the location of the anomally, automatically - The location of the anomally gets reported to MofW for inspection. After inspection, MofW will change the slow order as they see fit, or take the track out of service.
Leads me to wonder -- tongue only partly in cheek -- whether there ought to be some apparatus on the engine that can mark the rail with a different color than that used for any of the Sperry cars, to identify the precise location of an issue and perhaps allow recognition as a complication or new problem among perhaps-already-recognized issues even before the MoW people can get there to check things.
Something I'm still not quite seeing: the discussion clearly indicated that a 10 mph restriction was discussed for the rail section we're concerned with, but was not imposed (the 25 mph constituting 'slow enough' for their procedures). The problem is that too many 'foresight' 10 mph restrictions are going to cripple the railroad. Does the dispatcher have some idea of how serious a 'track anomaly' is from the description he gets and the questions he subsequently asks?
Hey, another potential use for those octos! Drop in and get some high-resolution pictures and scans...
Wizlish Something else that needs to be covered if we're going to start a shoulda-woulda-coulda blamefest on the part of the engineer noting the 'oscillation and noise' is the procedure by which those observations would work themselves 'quickly enough' up the chain of notification and down the chain of command to get quick remediation. Perhaps there needs to be some procedure (within CSX, or perhaps NORAC/GCOR more formally) for implementing the equivalent of a "911 call" that puts an automatic slow order out (via the PTC system, most probably, and presented as more a civil restriction than an operating one so it's understood clearly) - this would have some specific 'rapid response' checking with the database of track defects referred to in the testimony and ideally some feedback on this to the engine crew(s) concerned so they know what they might be experiencing. (Do I think that's practical to implement, or that crews would pay much attention to it if it generates 'cry wolf' slow orders too often? don't ask too often... but someone like Sarah might)
Something else that needs to be covered if we're going to start a shoulda-woulda-coulda blamefest on the part of the engineer noting the 'oscillation and noise' is the procedure by which those observations would work themselves 'quickly enough' up the chain of notification and down the chain of command to get quick remediation. Perhaps there needs to be some procedure (within CSX, or perhaps NORAC/GCOR more formally) for implementing the equivalent of a "911 call" that puts an automatic slow order out (via the PTC system, most probably, and presented as more a civil restriction than an operating one so it's understood clearly) - this would have some specific 'rapid response' checking with the database of track defects referred to in the testimony and ideally some feedback on this to the engine crew(s) concerned so they know what they might be experiencing. (Do I think that's practical to implement, or that crews would pay much attention to it if it generates 'cry wolf' slow orders too often? don't ask too often... but someone like Sarah might)
Current procedures - Crew reports track anomally - Dispatcher puts out Restricted Speed Slow Order for the location of the anomally, automatically - The location of the anomally gets reported to MofW for inspection. After inspection, MofW will change the slow order as they see fit, or take the track out of service.
EuclidMy thought was that the oscillation and rattling noise that the crew experienced when passing over the defect was an indication that the defect had evolved past the 5% fracture range where it stood the day before.
Where is it documented in the record that the oscillation and rattling were caused at the reverse-detail fracture site?
That's not to say it wasn't, but there is no smoking gun to indicate there wasn't in fact a catastrophic progression and break at the 5% reverse-detail fracture site somewhere back in the particular train, perhaps right at the point the evidence appears to indicate the first sign of wheel damage to a car (around the 33rd car, if I remember correctly).
If I remember there was a 20% transverse fracture present right in the vicinity, and this was the thing that 'tipped the balance' over into removing the whole 40-foot piece rather than putting in another set of joint bars and field-welding things. In the 2014 report, in fact, the accident was directly attributed to RCC-related failure, which would have to be something at the gauge corner or head/flank contact surfaces, and this assumption was the reason for the initial claim that the RSAC 'recommended procedure changes would have prevented the accident'.
As you noted, we need a careful timeline, and a carefully-done diagram showing all the defects organized east to west or vice versa, probably best in the direction of the derailed train's movement, within the context of how the track was aligned. There won't be any sense out of this except bandying claims forward and backward until we have distinguished the failures, and the propensity of each to have caused the particular derailment observed.
BTW, I did not find the level of detail in the parts of the interviews I read to be 'stunning'. In fact I find it astounding that the NTSB people either did not pick up on, or deprecated for some reason known best to themselves, the observation that Track 1 was preferentially underloaded relative to Track 2 (they say explicitly in the 2014 report that both tracks were approximately equally used, which was in one of the testimonies but not from the person responsible for track assignment...)
Something I do not know is whether the 'friendliness' of the investigators to some of the people called in was genuine, or the sort of technique used to 'gentle' potentially hostile or dissembling witnesses into letting their guard down and 'volunteering helpful information'. I like to think it was the former.
dehusman If they had dispatched somebody out to the scene how would they have : a) Found the 5% defect. b) Determined it had progressed to a larger state The rail had broken prior to the passage of the train that derailed, why hadn't the signal system indicated a track occupancy? I have a feeling that unless the rail was broken, any person inspecting the track would not be able to determine that there was a defect in the rail or its extent. It is entirely possible that they may have "determined" the noise, etc. was caused by some other factor (probably related to the previous repairs) and, depending on what the rest of the track looked like, might have at most put some sort of additional slow order on the track (10 mph?) which would have meant that the derailment would have probably still happened but at a slower speed. Unless the rail is broken, any noise or wobble would not be caused by the defect in the rail.
If they had dispatched somebody out to the scene how would they have :
a) Found the 5% defect.
b) Determined it had progressed to a larger state
The rail had broken prior to the passage of the train that derailed, why hadn't the signal system indicated a track occupancy?
I have a feeling that unless the rail was broken, any person inspecting the track would not be able to determine that there was a defect in the rail or its extent. It is entirely possible that they may have "determined" the noise, etc. was caused by some other factor (probably related to the previous repairs) and, depending on what the rest of the track looked like, might have at most put some sort of additional slow order on the track (10 mph?) which would have meant that the derailment would have probably still happened but at a slower speed. Unless the rail is broken, any noise or wobble would not be caused by the defect in the rail.
Dave H. Painted side goes up. My website : wnbranch.com
EuclidI think it would be an interesting challenge to rewrite this whole sequence about the development of the defect in a way that it could be understood. Certainly, the facts are available. They just have to be rearranged and presented without the smokescreen.
I second this motion. As part of that discussion, it seems to me that the noise and 'oscillation' reported had nothing to do with either the particular reverse-detail fracture or its timing as far as the "preventability" of this accident is concerned. However, it would be a fine demonstration of an 'enhancement' of the policy of the RSAC group about prompt action in cases of actual RCF involvement (particularly transverse gauge-corner fractures) OR to bump up priority in the 'automatic defect tracking system' in as close to realtime as possible when a crew reports common-sense signs of track damage on a section with other known (but not yet 'critical enough to prioritize') defects -- as appears to have been the case for the rail on Track 1 in Lynchburg.
Much of the discussion is going to hinge around two things: the defect-detection timeline and the physical defect types and locations in that "40' section' of rail that was scheduled for changeout on what turned out to be not-quite-just-in-time scheduling...
BaltACD Euclid Whatever was going on with the defect, it was felt and heard by the crew on the engine as they passed over it. I wonder if the previous train noticed any sound or oscillating movement when passing this defect. I wonder if the investigators asked that question. It would be interesting to ask the engineers of all trains that passed since the day before when the defect was scheduled for repair two days later. I also wonder if they asked the engineer of the derailed train what he thought when passing over the defect and noticing side to side oscillation and a rattling sound. And I wonder what caused the rattling sound. The only thing I can think of would be the truck wheel flanges snagging on the misaligned nature of the broken rail as if trying to climb the rail, but falling back down into proper position before being able to fully climb the rail. If T&E crews feel something about the track structure - they report it. If there was no report made to the Dispatcher about 'rough track', no rough track was felt. Since all radio communications between Train Dispatchers and field personnel are recorded - any period of time can be searched, and I am sure the NTSB in their investigation did review all radio communications on the territory.
Euclid Whatever was going on with the defect, it was felt and heard by the crew on the engine as they passed over it. I wonder if the previous train noticed any sound or oscillating movement when passing this defect. I wonder if the investigators asked that question. It would be interesting to ask the engineers of all trains that passed since the day before when the defect was scheduled for repair two days later. I also wonder if they asked the engineer of the derailed train what he thought when passing over the defect and noticing side to side oscillation and a rattling sound. And I wonder what caused the rattling sound. The only thing I can think of would be the truck wheel flanges snagging on the misaligned nature of the broken rail as if trying to climb the rail, but falling back down into proper position before being able to fully climb the rail.
If T&E crews feel something about the track structure - they report it. If there was no report made to the Dispatcher about 'rough track', no rough track was felt. Since all radio communications between Train Dispatchers and field personnel are recorded - any period of time can be searched, and I am sure the NTSB in their investigation did review all radio communications on the territory.
Euclid The rail defect is discussed in detail on page 8-11 in this NTSB report: http://www.ntsb.gov/investigations/AccidentReports/Reports/RAB1601.pdf I have read this several times, and find it to be incredibly confusing. Here is the text quoted from the report. I have revised the formatting and removed the foot notes. The following is quoted from the report: Reverse Detail Fracture The derailment occurred at a sudden break of a rail originating from a reverse detail fracture on the gage corner of the railhead of the high rail in the curve. A CSXT contractor performed ultrasonic testing in the area of the derailment the day before the accident. Investigators reviewed the ultrasonic test data for the failure location. The data confirm that the test equipment functioned properly and responded to known rail features that would normally be detected by the ultrasonic test probes within the area of the failed rail. The data showed defects discovered during the ultrasonic testing including a 20 percent transverse detail fracture; this was noted as number 151 on Sperry report number 119A, dated April 29, 2014. CSXT Petroleum Crude Oil Train Derailment and Hazardous Materials Release NTSB/RAB-16-01 9 The size of a rail defect determines if mitigation is required by FRA regulation. The suspected rail defect that failed at the point of derailment was a 5 percent reverse detail fracture. Historically, regulations have not considered 5 percent reverse detail fractures to be a defect subject to complete failure prior to progressing to a larger size. These types of defects cause a stress concentration on the surface of the rail and may cause a complete rail failure at a much smaller size than typical detail fractures. Rolling Contact Fatigue Rolling contact fatigue results from the cumulative effects of railhead wear and rail surface conditions, such as shelling, head checks, or flaking. The detrimental effects of rolling contact fatigue can occur before a worn railhead profile or side wear is noted. Rail wear on the gage corner and side of the rail are easier to find and manage; however, the detection of fatigue in the lower corner of the gage face of the rail is more difficult. That part of the railhead it not easily scanned by ultrasonic equipment, and a regulatory remedial action was not mandated to address these flaws. A stress concentration, often called a stress riser, is a location in an object where stress is concentrated. Shelling is a progressive horizontal separation that may crack at any level on the gage side, generally at the upper gage corner. It extends longitudinally—not as a true horizontal or vertical crack, but at an angle related to the amount of wear. Flaking is a progressive horizontal separation on the running surface of the rail near the gage corner, with scaling or chipping of small slivers. Flaking should not be confused with shelling, as flaking takes place only on the running surface near the gage corner of the rail and is not as deep as shelling. Head checks are transverse surface cracks on the gage corner of rails resulting from cold working of surface metal. These are sometimes referred to as gage cracks. The FRA Track Safety Standards do not address this type of rail defect at the size that failed in the Lynchburg accident (5percentreverse detail fracture). The FRA remedial action chart addresses transverse detail fractures, but does not mandate remedial action until the defect is 20 percent or four times the size of the defect that caused this derailment. At that time, the railroad owner would be required to reduce speed to no more than 30 mph and apply joint bars within 20 days to the defective rail condition. Post Accident Actions CXST Prior to the Lynchburg accident, if a transverse detail fracture had been20percentof the cross-section of the rail head, CSXT engineering standards required that the defective rail be changed out within 5days or joint bars be installed to the rail at the site of the defect. Since the ultrasonic testing data indicated a transverse detail fracture near the location of the derailment, CSXT planned to replace the rail on May 1, 2014. Since the operating speed for that area was 25 mph, the rail defect did not require a speed restriction in accordance with CSXT maintenance procedures or FRA regulations. FRA Rail Failure Working Group Recommendations The NTSB derailment investigations in New Brighton, Pennsylvania; Columbus, Ohio; and Ellicott City, Maryland, led the FRA to determine that each of the accidents resulted from rail failures. In September 2012, the FRA established a Rail Safety Advisory Committee (RSAC) Rail Failure Working Group to address rail wear issues such as rolling contact fatigue. The working group studied the effects of railhead wear and resulting rail surface conditions (better known as rolling contact fatigue) and how such rail conditions can adversely affect the results of ultrasonic rail testing. The Rail Failure Working Group met four times beginning in January 2013, and completed its task on July 31, 2013. The group proposed new performance-based recommendations for determining rail wear and internal rail inspection criteria. These criteria ensured the FRA’s ability to effectively monitor rail integrity programs that require track owners to quickly identify and remediate areas that could lead to a derailment. The FRA’s efforts and industry’s acceptance of these best practices should significantly reduce rail accidents caused by broken rails resulting from rolling contact fatigue and improve the industry’s rail risk management programs. The RSAC adopted the Rail Failure Working Group recommendations on April 16, 2014. The final recommendations developed with industry and other stakeholders formed a consensus document of best practices or guidelines to manage the risks related to rail wear and rolling contact fatigue. Before the guidelines were implemented by CSX, the Lynchburg accident occurred; if they had been implemented, this accident would likely have been prevented. [End of quote]
Hindsight is always 20/20 - foresight is generally 20/400 or worse.
Euclid I don’t see how it can be concluded that a 5% fracture does not require immediate action.
I would opine that perhaps 5% fractures have been found to last some period of time before getting worse. In fact, I'd imagine that if railroads had found that a 5% fracture was a significant problem, then they would have policies in place for immediate replacement.
It could also be that a change in the type of traffic might, indeed, exacerbate the issue. And that result may not have become apparent in the MOW crystal ball.
Wizlish Euclid There was policy in place that allowed the defect repair to be delayed after discovery. So they scheduled the repair for two days later. The defect caused a train wreck one day later. Is it not logical to conclude that there was something wrong with the policy? I'm sure for you it's logical. I don't have that good 20/20 foresight.
Euclid There was policy in place that allowed the defect repair to be delayed after discovery. So they scheduled the repair for two days later. The defect caused a train wreck one day later. Is it not logical to conclude that there was something wrong with the policy?
I'm sure for you it's logical. I don't have that good 20/20 foresight.
Apparently some of the dates of these 'reports' vary depending on the agency involved. I managed to track down something potentially relevant, that the origin of the specific RSAC working group (in 2012) was related to issuance of a specific recommendation from an earlier accident (the ethanol train in New Brighton, PA). The history of how this recommendation came to be 'closed by alternative means' is probably highly relevant to the current discussion.
http://www.ntsb.gov/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=R-08-011
Note the association of defects with 'wear' -- I am still looking to see if there is a specific association between 'special treatment for reverse-detail fracture defects' and specific levels of observed wear or markers of fatigue.
I continue to think there is another aspect in here somewhere that has not been completely brought out. This is supposition based on testimony, but y'all can fact-check it against the source material to some extent. There were two tracks, on a line that essentially had 'single-track throughput'. The two tracks in the section involved were not utilized equally, with Track 1 receiving far less MGT/year than Track 2, apparently at least partly through preferential dispatching of empties on that track. It might follow that preferential dispatching of HHFT or hazmat might be done on this track because it would (presumably) have lower average wear or RCF defect probability.
Meanwhile, we also find that because of the lower loading, the maintenance cycle for rail inspection was much longer (123 days vs 31, was I think the figure given) and, at least prospectively, defects not immediately identified as critical would have a longer 'response time' (due to the lower expected average loading?).
I have the suspicion that the different priorities resulted, here, in a 'catch' situation where a more unsafe condition was produced by efforts to produce a safer one. I do not think it would be fair either to tar CSX maintenance for making this mistake or to assume that rules for correcting RCF-related defects more quickly would necessarily have caught this particular one, and it would appear (from the CSX representative's comments in the News-Leader article) that CSX has voluntarily adopted a far more rigorous standard for repairing defects in this general situation than the Federal rule (that supposedly 'would have prevented this') calls for. However, I wonder whether there should be a wider recognition of the general principle that routing 'key' trains on less-utilized parts of the track structure, in order to expose them to a lower probability of wear-associated track defects, needs to be matched with a higher level of detection and response corresponding not to average track-related measures but to the 'key' nature of the trains themselves. If I am not mistaken, some of the recent safety recommendations and legislation do call for this, but I am still not sure that the specific RSAC rail integrity group's report specifically addresses how the reverse-detail fracture was to be detected and remediated in a short timeframe (vs. the circumstantial observation that it would have been removed in track scheduled for remediation 'by other means' for other defects). And I would repeat that the discussion involves only reverse-detail fracture in this context when discussing anything that 'would have prevented this accident' in any meaningful context that is a useful predictor for future prevention of similar problems.
EuclidThere was policy in place that allowed the defect repair to be delayed after discovery. So they scheduled the repair for two days later. The defect caused a train wreck one day later. Is it not logical to conclude that there was something wrong with the policy?
I am not altogether sure, having looked over a couple of the interview transcripts, that the thing is as 'open and shut' as finding defects and ordering them all fixed ASAP (which is what appears would have been required to 'prevent' what happened for this specific defect). If I understand correctly, they made a decision to replace a full piece of rail rather than patch a defect for two days and then remove it. An interesting thing is that they talk about imposing a slow order (10 mph) before fixing a defect 30" from a bad weld, but I don't get the impression that is that same defect elsewhere described as a reverse detail failure that was the supposed proximate cause of the derailment.
Reading between the lines, there may have been a bad batch of rail involved in this section, and it may be interesting to see how that 'angle' develops. Look at this transcript of how the testing was done on this segment and compare to a couple of the other interviews.
I was particularly interested to see how the discussion of MGT wear on the double track developed between the questions asked in the first interviews and the information between Track 1 and Track 2 use that came up in this one.
EDIT - let me find exactly what the working group changes involve regarding reverse detail fractures and then see how this would affect systematic predictive repair. I find I misunderstood what you were saying and will correct that before commenting further on this aspect. Out of curiosity -- are you using Martz' article in the Richmond paper as source material, or have you looked at the actual working-group study?
FURTHER EDIT: I came across this .pdf of an earlier state of the NTSB report, which has some highly interesting 'conclusions' in it. Among other things, they apparently get the MGT of Track 1 wrong, they attribute the rail failure to rolling-contact fatigue damage wrongly, and they quote the findings of the RSAC rail failure working group in their Appendix B ... noting that the results of the study would have prevented the accident if its cause had been rolling-contact fatigue. With that not being the case, I have to review the actual RSAC material to see what is different.
Incidentally, there is something else valuable in this report that has not been discussed at all adequately: the specific mode of failure for the 1232 car that was so radically breached. Note that this was not a 'puncture', but caused by something that 'scraped' across the car until it 'picked' a circumferential weld, and then apparently followed the weld (either by failure or preferential 'guiding') leaving what was described as curls of metal inside the tank. Remember that this occurred from a speed below 25 mph.
You're picking the wrong nits again.
The first point: Reverse detail fractures are difficult to detect. An associated point, not entirely made clearly (and buslist is better qualified to address this specifically) is that disambiguating ultrasonic or other test detail to produce evidence of an early case of RDF is difficult.
The second point: it's 20%, not 5%, that constitutes the 'threshold' for the usual kinds of transverse failure, the point at which the railroad would have (promptly!) dispatched a crew to put on just the sort of 'remediation' they did 30" west. Now, your point about the potential importance of a 5% reverse detail fracture is well taken; the report does note that this kind of failure is notable for quick catastrophic progression from even slight extent (or so I understood the report to say). Your first 'rubrics' are addressing the perception in the industry that RDFs were not considered more critical at very early stages than more common kinds of transverse failure, most notably those more directly attributable to RCF.
How the second point concerns this is not quite clear. I do not know, although I presume buslist and others do, whether the 'recommendations' you are describing in the second red passage specifically involve a requirement to repair RDFs promptly whenever detected at 5% or greater level ... which necessarily presupposed a requirement to detect them and then characterize them accurately in the first place, with minimum latency. Perhaps we'd better look at and discuss the specific passages and context of the 'recommendations' before addressing whether the conclusions are even at all germane to this specific failure ... let alone something that would have produced definitive preventation if applied.
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