Train crash in Ohio 19

[spsalso]

https://www.cbsnews.com/news/ohio-train-derailment-causes-big-fire-evacuations/

Note the mention of extremely low temperatures.

I suspect that is the cause*.

And I suspect the train crew should have been told to operate at restricted speed, because of that possibility.

And/or the trackage should have been installed taking into account these temperatures.



spsalso


*I'm talking about the effects of rail contraction at cold temperatures. A rail joint could have failed. Or rail could have been pulled up on a curve. I suppose a rail could even have snapped.

Besides restricted speed, there's also the running of an inspection car ahead of the train.

 

[Factoter]

NTSB is saying car number 23, video of sparking truck, started the fire; Polypropylene pellets, that then spread to the other cars in the pileup. No specifics of the derailment itself, but suggesting emergency brakes?
One point is the HBD temp. of 253*F above ambient. The doorbell video that circulated showing light flashes from the wheels suggests the sensitivity is limited somewhat.

 

[TugboatEng]

Just to make an out of the box thought, there have been big changes in the engine of trains without big changes in the train itself. When diesel locomotives really started to catch in the EMD 16-567 engine and Alco 251 were the big power engines but both were only around 2000hp. Caterpillar shoved a 3616 engine in a few trains that made 10,000hp but they didn't catch on for a few reasons. Regardless, EMD and GE have engine options that exceed 6000hp but every mechanical component of the train is still legacy from the 2000hp days.

In the tugboat industry we have recently been spoiled with inexpensive high-speed engines that make huge horsepower numbers and they're coupled with 360 degree thrusters that can generate 100% thrust in all directions. Early constructions were fine due to conservative factoring but newer constructions are falling back on generalized rules and the hulls are failing.

There may need to be an evaluation of the power of each train relative to construction or configuration.

 

[dik]

I don't think that 253F is even close, judging from the glow...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[IRstuff]

https://www.npr.org/2023/02/23/1158...ailment-ntsb-preliminary-report-wheel-bearing

The 254 F temperature is simply what the last hotbox detector read, and since that was above 170, the train's operator attempted to stop the train, but a nearly 2-mile long train takes a lot of time and distance to stop, and by the time the train came close to stopping, the truck was already on fire.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[dik]

I realise that... but the increase in temperature would have run up a flag. The 103F would have prompted a concerned 'check'. That's why there should be a requirement for any significant 'change in temperature' readings. The criteria is faulty.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[spsalso]

"Regardless, EMD and GE have engine options that exceed 6000hp but every mechanical component of the train is still legacy from the 2000hp days."

Railroads run multiple locomotives. They can easily put 15,000HP on the front of a train. The Union Pacific has been doing so for upwards of 50 years.

EMD produced, in 1969, a 6600 HP locomotive, of which 47 were bought by Union Pacific. It was common to run two of these together, with another "regular" locomotive to achieve the nominal 15,000.

Union Pacific purchased 31 gas turbine locomotives that produced 8500 HP in 1958-61.

And just a wee bit earlier (1944), that railroad operated 25 steam locomotives producing 6200 HP. But rarely in multiple.




spsalso

 

[JohnRBaker]

Speaking of "turbine locomotives", in Ogden, UT, at the old Union Station, which is now a museum, they have on display one of the two remaining examples of a GE Super Turbine Locomotive:

September 2008 (Canon IXUS V)

September 2008 (Canon IXUS V)

September 2008 (Canon IXUS V)

September 2008 (Canon IXUS V)

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[FacEngrPE]

https://www.up.com/aboutup/special_trains/gas-turbine/index.htm

https://en.wikipedia.org/wiki/Union_Pacific_GTELs

Turbine powered locomotives cost less to operate than the UP steam engines they replaced, but are not economical when compared to the diesel locomotives that were put to work in the i960's.

All of the EMD (now progress rail / caterpillar)current offerings for North America are listed at 4300 or 4400 HP.
GE Rail (now WABTEC) most popular locomotives are also this size, but there is an offering at 6600HP

Relevant to our discussion, too much tractive effort at the head end can pull the car string apart. Hence locomotives are distributed along the length of the train to limit coupler tensile and compressive loads on the very long trains of today. I wounder how the NTSB will view distributed power? Did it help or hurt?

 

[TugboatEng]

How many cars had the hazmat vinyl chloride in them? 2? How many in total derailed? 50? It doesn't seem like reducing the number of cars derailed would provide much benefit in the overall picture. Maybe some thought needs to go into getting the derailed car clear of the tracks faster so the rest of the cars don't wad up into it.

 

[spsalso]

There were 5 cars with vinyl chloride, out of 38. Other loads that wrecked that could be a problem:

2 combustable liquid
1 isobutylene
1 butyl acrylate
2 benzene
2 polyethylene
4 polyvinyl
5 petroleum lube oil
1 paraffin wax


On the other hand, shortly behind the mess, there was 9 cars of malt liquor that remained non-derailed. FWIW.


You really can't get "the derailed car clear of the tracks faster so the rest of the cars don't wad up into it". It's pretty much like a crash on the freeway when everyones following WAY too close.


spsalso

 

[davidbeach]

That's why any train longer than X cars should be required to have EP brakes. Much of the derailment mess is because the front end of the train stops quicker than the rear end of the train.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[spsalso]

"That's why any train longer than X cars should be required to have EP brakes. Much of the derailment mess is because the front end of the train stops quicker than the rear end of the train."

There would have been a big mess anyway. The question is in what way would it be better.

What did happen is the first 22 cars stayed on the track, the next 39 went on the ground, and the remaining 79 cars stayed on the track.

How would EP brakes improve things? How many fewer cars would have crashed?


spsalso

 

[TugboatEng]

That is why the rail industry pushed to end the EP regulation. They estimated it would reduce derailments by 1.6 cars and cause many additional breakdowns.

In my personal experience, EP systems tend to be very reliable, I don't know where their complaint comes from. A refrigerated air dryer helps but they're very expensive because everybody puts them in the LP side of the system...

 

[spsalso]

Well, if it reduced this crash by 1.6 cars, that ain't much.

Of course, you can ask what happens when only one car crashes--does it then hop back on the track?



spsalso

 

[TugboatEng]

Re-railings have happened.

 

[spsalso]

Yes.

But I wouldn't want to count on it.


spsalso

 

[TugboatEng]

As an off-road motorcycle rider we always had the saying, "if in doubt throttle out". Hitting the brakes can make a lot of situations worse. Extra power usually pulls you out of that bad situation. Maybe increasing power during such a failure would prevent the buckling action that leads to derailment. The derailment did happen during full dynamic braking. Full dynamic braking may have been the worst choice of action to take.

 

[spsalso]

Since the engineer had no reason to assume the train would "buckle", there was no reason to add extra power to prevent it. By the time the train actually buckled, the air brake line was disconnected between those cars and the front of the train, and the engineer had no more input.


I would think dynamic braking would be an excellent choice for slowing a train, based on what the engineer knew. And didn't know. It is quite common for the problem to be sticking brakes; so staying away from brake usage appears to me to be the best choice.



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[TugboatEng]

Keeping the train with a little tension at the couplers prevents the buckling that lead to the cars turning completely sideways. Even if it doesn't prevent the derailment, having the cars derail inline with the tracks instead of wading up into a pile would be make the disaster response and cleanup a lot easier.

Just sharing a thought. Hitting the brakes isn't always the best remediation to a problem.

There was some complaint from truckers about governors a while back. In the event of a front wheel blowout you're supposed to accelerate at full throttle until everything stabilizes. Trucks running on the governor are not able to accelerate resulting in crashes after a front tire blowout.

 

[spsalso]

No. Not in this case.

The cars turned completely sideways because each of the preceding cars stopped abruptly, while the following cars did not. Until THEY stopped abruptly.

And etcetera...

When a freight car weighing 120 tons is no longer supported by its trucks, it falls to the ground, engages the ground, and tends to stop very quickly. The following cars keep rolling until they are also stopped abruptly by the various preceding now-stopped cars. The only reason the whole rear of the train did not pile into the crash is that the brakes automatically went into emergency when the crash happened. Plus there was one trailing locomotive which did whatever it automatically does in such a situation.

IF the entire train had been equipped with the previously mentioned EP brakes, several of the final "crash victims" probably wouldn't have.


spsalso