NTSB Preliminary Report RRD23MR005 Norfolk Southern Railway Train Derailment

[Hiawatha Pete]

Reposted from LBN as per recommendation from forum hosts:

Source: National Transportation Safety Board
https://www.ntsb.gov/investigations/Documents/RRD23MR005%20East%20Palestine%20OH%20Prelim.pdf

Issued: February 23, 2023

"On February 3, 2023, about 8:54 p.m. local time, eastbound Norfolk Southern Railway (NS) general merchandise freight train 32N derailed 38 railcars on main track 1 of the NS Fort Wayne Line of the Keystone Division in East Palestine, Ohio. The derailed equipment included 11 tank cars carrying hazardous materials that subsequently ignited
Train 32N was traveling about 47 mph at the time of the derailment, which was less than the maximum authorized timetable speed of 50 mph.

Train 32N was operating with a dynamic brake application as the train passed a wayside defect detector on the east side of Palestine, Ohio, at milepost (MP) 49.81.
The wayside defect detector, or hot bearing detector (HBD), transmitted a critical audible alarm message instructing the crew to slow and stop the train to inspect a hot axle. The train engineer increased the dynamic brake application to further slow and stop the train.
During this deceleration, an automatic emergency brake application initiated, and train 32N came to a stop.

On the Fort Wayne Line of the Keystone Division, NS has equipped their rail network with HBD systems to assess the temperature conditions of wheel bearings while en route. The function of the HBD is to detect overheated bearings and provide audible real-time warnings to train crews. Train 32N passed three HBD systems on its trip before the derailment. At MP 79.9, the suspect bearing from the 23rd car had a recorded temperature of 38F above ambient temperature. When train 32N passed the next HBD, at MP 69.01, the bearing's recorded temperature was 103F above
ambient.
The third HBD, at MP 49.81, recorded the suspect bearing's temperature at 253F above ambient.

NS has established the following HBD alarm thresholds (above ambient temperature) and criteria for bearings:
Between 170F and 200F, warm bearing (non-critical); stop and inspect
A difference between bearings on the same axle greater than or equal to 115F (non-critical); stop and inspect
Greater than 200F (critical); set out railcar"

Read more: https://www.ntsb.gov/investigations/Documents/RRD23MR005%20East%20Palestine%20OH%20Prelim.pdf

________________________________________________________________________________________________

Key points & takeaways in the NTSB preliminary report:



1) The train was operating within allowable speed limits (paragraph 1 above)

__________________________________


2) The train was operating in dynamic braking mode (paragraph 2 above). Dynamic braking is an additional braking system over & above the airbrakes and involves the use of the electric traction motors on a diesel-electric locomotive to slow the train.

In many cases dynamic braking alone will just about hold back what tonnage a locomotive can pull, with conventional airbrakes being "blended-in" at lower speeds to bring the train to a complete stop.

Furthermore, the NTSB Chair has issued a statement indicating that the use of conventional airbrakes was not the root cause of the derailment:
(Per my prior post at: https://www.democraticunderground.com/10143035850 )

__________________________________


3) The rail car that initiated the derailment had an overheated wheel bearing (paragraphs 3 & 4 above)

A device that can play a role in preventing derailments is the wayside hot-box detector. It uses infrared sensors to detect bearings, axles or other components of a rail car that are overheating, then uses radio signals to flag rail crews of any overheated components.

Train 32N passed three HBD systems on its trip before the derailment, and these hotbox detectors appeared to be working.

At Mile 79.9, the suspect bearing from the 23rd car had a recorded temperature of 38F above ambient temperature.

At Mile 69.01, the bearing's recorded temperature was 103F above ambient.

At Mile 49.81, the HBD recorded the suspect bearing's temperature at 253F above ambient.


Between 170F and 200F above ambient temperature the rules state for the crew to stop and inspect the train and greater than 200F the crew must uncouple the defective railcar from the rest of the train.

As per the operating rules, the bearing temperature threshold that would invoke stopping the train and remedial action by the crew was not reached until Mile 49.81 - right at the east side of Palestine, Ohio

__________________________________


4) The report also indicates that the partners in the investigation include:

The FRA,

Norfolk Southern Railway,

Trinity Industries Leasing Company,

and GATX Corporation among others.


In most cases, the companies that own the railcars are the ones responsible for railcar safety inspections. Norfolk Southern does not own the railcars but owns the locomotives & right of way.

____________________________________

Summary:


The root cause of the derailment was not brakes, but an overheated bearing on one of the railcars owned by a third party.

The wayside sensors appeared to be working correctly and the crew following the operating rules

The NTSB investigation is still ongoing and will be up to them to determine whether the 3rd-party railcar owners, &/or Norfolk Southern & other parties bear - or share - in the responsibility.

It will also be up to them & the FRA to determine if required, and recommend & enforce, any changes to the operating rules such as lowering the temperature threshold (recorded by the hotbox detectors) at which to stop a train

[Disaffected]

1. It is quite striking how the official report findings differ

from most of the debate/rumors/innuendo/false information seen on many forms of media.

Perhaps the most striking - faulty/antiquated brakes were not the cause of the accident.

ETA: Now let's wait for the official report on the S Carolina balloon. It will be interesting to see how right or wrong the "pundits" were on that one.

[Hiawatha Pete]

4. Agree 100% . Too bad hotbox detectors only understand empirical & don't understand political. n/t

[Disaffected]

6. Another case in point; when some of the attention shifted to hotbox issues,

there were even claims that the detectors were not working and, which was a result of shoddy/downgraded maintenance regulations.

[W_HAMILTON]

7. Most informed people were not claiming that the brakes were the CAUSE of the accident.

They were claiming that with a more modern advanced braking system in place, the accident wouldn't have been as severe due to that system having much better reaction time in the event that derailment of another car does take place.

[Hiawatha Pete]

9. There are already advanced brake systems in place. See point #2 above.

2) The train was operating in dynamic braking mode (paragraph 2 above). Dynamic braking is an additional braking system over & above the airbrakes and involves the use of the electric braking to slow the train.

Are you saying that the Siemens, GE & Mitsubishi-designed IGBT-based traction inverters which control the dynamic braking on US diesel-electric locomotives are not advanced?

https://studylib.net/doc/18490874/igbt-based-inverter-system

If so, do explain.

[W_HAMILTON]

11. I was clarifying what most of the claims actually were.

I don't claim to know the various brands and models of brake systems, but you seem to, since you were the one that was commenting on it several times in the past and were making definitive claims one way or the other (example: https://www.democraticunderground.com/100217645420), so you tell us: were the brakes used here the "electro-pnuematic braking system" -- your words -- that were referred to in the regulation that was frequently cited?

[Hiawatha Pete]

12. Dynamic brakes & EP brakes are two different systems. Air brakes a third.

I know what I said.

[W_HAMILTON]

14. I am asking you to clarify.

When I referred to the more modern advanced braking system, I was referring to the ones in the regulation that everyone was referring to at the time.

So, are the brakes mentioned in this report of that same type that were called for in the regulations being discussed -- yes or no?

It sounds like your answer is no, in which case, no, then the braking system was not the more advanced type I was referring to when you first asked me about it.

Glad to clarify!

[Hiawatha Pete]

15. All US diesel locomotives have both dynamic & air brakes. The NTSB is aware of that.

Not sure if the resident experts at LeverNews and David Sirota are, though.

In addition to these two systems, the EP (electro pneumatic) system is used on passenger trains & transit.

Very few systems anywhere in the world use EP brakes on freight trains. Australia experimented with one on a very long test train recently.

It will be for the NTSB to decide if EP (or ECP as the media is calling it) brakes are the way to go.

[WhiskeyGrinder]

3. how can we be mad about it if it doesn't have something we can pin on a political figure

[Hiawatha Pete]

5. Too bad hotbox detectors only understand empirical & don't understand political. n/t

[lapfog_1]

10. Between 170F and 200F, warm bearing (non-critical); stop and inspect

and the 10 to 11 miles between the HBDs would seem to be the main problem.

Not to mention that there is video of the train passing a crossing with flames shoots out from underneath at least 1 car.

The threshold for HBD warnings is too high.
The frequency of such detection needs to be more...

Finally... having a camera on the train to visualize all of the cars, whether such cameras are ground based (included with the HDB) or on every train car and wifi'd to the cab, might have given the train crew more warning that there was a serious problem BEFORE the car derailed.

And, in general, rollback of regulations was inviting this SORT of disaster (even if the specific regulation on modern braking systems was not involved). The criticism of the Trump admin's rollback of regulations is well deserved.

It would seem that we need way more regulations, not less.

Finally, another regulation that I would propose (that DID make this disaster worse) is how the train was put together and how many various chemical tanker cars it consisted of and how many should be allowed. Limiting the number of tanker cars that make up a train might cost more money, but the size and scope of future derailments and crashes (there will always be accidents) needs to be limited.

[Hiawatha Pete]

13. "The criticism of the Trump admin's rollback of regulations is well deserved"

Last edited Thu Feb 23, 2023, 07:25 PM - Edit history (3)

Yes, by all means do so. Just make sure you have the facts in hand.

And please do not conflate the terms root cause with mitigation
The root cause was a bearing. The mitigation method was brakes.

Was the solution to the Ford Pinto problem to issue every driver and passenger a fire extinguisher?
And unlike the Ford Pinto, in this case we have a system (air & dynamic braking) that's worked for decades.

Also it seems you missed the fact that I did, in fact, mention HBD thresholds. It's the very last point in my OP.

[lapfog_1]

22. I don't believe I missed anything

The root cause was a bearing.
The failure was DETECTION.
The mitigation was to stop the train.

However there was a meta problem... the makeup of the train itself. Caused by not classifying the dangerous cargo correctly and having to much of different dangerous cargoes that made up the train. And these WERE regulations relaxed by Trump.

I didn't say anything about the brakes.

And I didn't say anything about you including or not including the spacing or threshold setting of the hot box detectors.

My point is that even if tougher regulations about HBDs and other detection methods are adopted, these sorts of accidents will still happen and devastate communities. One possibility is that we find substitute chemicals instead of these dangerous chemicals. Failing that, spend the extra money to limit the amount that is carried by one train, thus limiting the amount of damage when the inevitable accident happens.

[Hiawatha Pete]

23. Railroads carry dangerous goods because they are required to by law.

FYI bearing temp is a function of speed - speed goes up, temp goes up. At about 50mph a normal temp could well be around 100F above ambient.

What isn't mentioned is the fact that after a stopping to inspect, crew must proceed at restricted speed until a favorable reading is reached.

Also, wrt detector intervals, it's about the same as Europe: https://publik.tuwien.ac.at/files/pub-bi_5916.pdf In many instances detectors are only a few miles apart.

The NTSB will determine the best course of action - whatever that may be. They have an entire team of extremely well qualified specialists & engineering professionals.

__________________

PS: My wife & I have traveled in excess of a quarter million miles on Amtrak & VIA.

Rail, whether freight or passenger, is one of the safest modes, period.

Ref: According to the United States Department of Transportation, more than 500,000 truck accidents occur each year.
https://www.friedgoldberg.com/truck-accident-lawyers/common-types/tanker-truck-accidents/#:~:text=According%20to%20the%20United%20States,truck%20accidents%20occur%20each%20year.

[WarGamer]

16. Everyone should read this... very illuminating.

[Hiawatha Pete]

19. Thanks!

[rgbecker]

17. What I heard was there was something on the track that knocked the cars off...

Hunter Biden's laptop?

Probably

[Hiawatha Pete]

18. I heard from MTG that it was Hillary's emails n/t

[Takket]

20. so if i'm reading this right...

Train 32N was operating with a dynamic brake application as the train passed a
wayside defect detector on the east side of Palestine, Ohio, at milepost (MP) 49.81.4
The wayside defect detector, or hot bearing detector (HBD), transmitted a critical
audible alarm message instructing the crew to slow and stop the train to inspect a hot
axle. The train engineer increased the dynamic brake application to further slow and
stop the train. During this deceleration, an automatic emergency brake application
initiated, and train 32N came to a stop.5

5 An automatic emergency brake application is the full application of a train’s main air brakes.
An automatic emergency brake application can occur when a train experiences a separation that
disconnects the air brake hoses between railcars.

~snip

The report doesn't come out and say this but implies it in the footnote..... they were in the process of stopping the train, and then the emergency air brakes engaged because, and I'm assuming here, the derailment BEGAN at this point which caused a "separation that disconnects the air brake hoses between railcars". Is that correct? The derailment began while they were already slowing, but it simply did not happen fast enough to stop before the derailment.

[Hiawatha Pete]

21. It sounds plausible

Last edited Thu Feb 23, 2023, 07:39 PM - Edit history (1)

(that some cars had separated and dumped the air, putting the train into emergency brake)

But I'll wait for the NTSB final report before making any assumptions... n/t