2 Causal

There’s a small town in the U.S. state of Ohio called East Palestine.

A small house in this town might look like this:

Midjourney House in East Palestine

Imagine you live in this house, and one winter’s night you’re sitting at home scrolling on your phone when you hear screaming metal followed by a huge explosion.

You go outside and see this:

Smoke_from_the_2023_Ohio_train_derailment_taken_during_the_night,_February_3_(cropped)

(Wikipedia)

Your first question might be, “What happened?”

That would be a factual question along the same lines as, "Is the Bigfoot video real?"

The answer is that a 150-car, 3km-long train, carrying hazardous chemicals, derailed outside your town and caught fire.

The accident causes total chaos: people have to be evacuated, chemicals leak into the waterways and kill thousands of fish, people say their pets died from the gases, other people say they’ve been poisoned, and the whole thing takes weeks to get cleared up.

2023_Ohio_train_derailment

(Wikipedia)

Your next question, as somebody living in the middle of this, might be, “How did this happen?”

You would ask that because you wanted to know if someone was responsible for the crash, or if it was bad luck, and if it could ever happen again.

“How did this happen?” is a causal question.

Why don’t you take a guess? Describe a chain of cause & effect that might have caused the train to derail. (You can make it up so long as one thing leads to another.)

Here’s an article published 3 weeks after the accident, describing how experts identified a single overheated wheel bearing as being the cause of the problem.

Can you see any words and phrases that explicitly link causes & effects?

As the train approached East Palestine, a wheel bearing on its 23rd railcar rapidly overheated, its temperature soaring to more than 250 degrees Fahrenheit above the ambient outdoor temperature of 10 degrees.

The overheating triggered an alarm, which caused the train's engineer to immediately apply the brakes to bring the train to a stop. An automatic emergency braking system also came into effect.

But when the three-person crew exited the train to inspect the bearing, they saw fire and smoke, an indicator of a possible derailment, the report said. Ultimately, 38 cars derailed, 11 of which carried toxic chemicals.

Here's the most thorough explanation yet for the train derailment in East Palestine

One of the challenges with causal arguments is deciding how much detail you need to go into in order to provide a convincing explanation.

For example, are there any holes in the explanation above?

Are there any questions you would ask here? Any more info you would want? (Remember, it was a big explosion with a lot of bad smells and dead fish!)

One question you might ask is, "If there was an alarm, why did it go off too late to do anything?"

The same article addresses that by explaining how the “sensors that detect and report problems with signals and axles as trains pass by” are spaced on the railroad track.

Can you see any words and phrases used to link specific causes & effects?

Three such sensors, also called hot-box detectors, were located along 30 miles of track near East Palestine. They recorded increasing temperatures in the suspect wheel bearing, investigators said.

The first detector recorded a temperature of 38 degrees Fahrenheit above the ambient temperature, the report said.

By the time the train reached the second detector 11 miles later, the bearing had reached 103 degrees above the ambient temperature.

The third and final detector, located 19 miles later just east of East Palestine, recorded such a high temperature — 253 degrees Fahrenheit above ambient temperature — that the train's crew was alerted to stop the train and inspect the bearing in accordance with Norfolk Southern safety guidelines, the NTSB report said.

Only the third reading was high enough to trigger an alarm, according to the report.

On hearing the alarm, the engineer "responded immediately" to begin bringing the train to a stop, Homendy said, but as the train decelerated, the wheel bearing failed.

Here's the most thorough explanation yet for the train derailment in East Palestine

That sort of explains what happened, but we could keep digging: if the wheel was already too hot by the third detector, why didn’t the second detector send an alarm?

Norfolk Southern safety guidelines do not require train operators to take action until wheel bearings reach 170 degrees Fahrenheit above ambient temperature, the report said. Once a critical level of 200 degrees Fahrenheit is reached, Norfolk Southern requires its train operators to stop a train immediately and remove the affected car from the train.

Here's the most thorough explanation yet for the train derailment in East Palestine

So the company policy told the crew to stop the train once the bearing (in this instance) was already too hot, and the sensors that measured the overheating were spaced too far apart to catch it in time.

Let's keep digging! What causes a wheel bearing to overheat?

For that, we have to go to a different article:

There are several causes for overheated roller bearings, including fatigue cracking, water damage, mechanical damaging, a loose bearing or a wheel defect, according to the NTSB, and the agency says they’re investigating what caused the failure in East Palestine.

“Roller bearings fail, but it is absolutely critical for problems to be identified and addressed early so these aren’t run until failure,” Homendy said. “You cannot wait until they’ve failed. Problems need to be identified early, so something catastrophic like this does not occur again.”

Hot box detectors didn’t stop the East Palestine derailment

If the wheel bearing was damaged, why wasn’t it found and replaced earlier?

Jason Cox of the Transportation Communications Union testified that since 2019, Norfolk Southern has slashed the number of expert car inspectors it employs, and that it had been exploiting a loophole in Federal regulations by having train crews do a 12-point inspection on railcars instead of the 90 to 105-point checks done by an expert carman. He also testified that the defective car had passed through three railyards without being inspected by on-duty qualified personnel. He said that the 12-point inspections are "just supposed to be a stopgap to get the freight car to an inspection point," but they were increasingly becoming the primary method across the industry.

2023 Ohio train derailment

Do you notice how that last snippet doesn't have any words that explicitly link cause & effect?

Instead of spelling out "this caused that", the snippet only implies a causal relationship.

The reader needs to infer that if the company slashed inspections, then it's more likely that a damaged wheel-bearing would be left in place for too long.

It seems like we've got to the bottom of the story!

Though, knowing what you now know, you might want to ask, what if sensors had been placed closer together along the train line? Would that have helped?

More frequent sensors may have helped.

But with 19 miles between detectors, the wheel bearing heated beyond the train operators' ability to stop the train safely, the NTSB said.

"Had there been a detector earlier, that derailment may not have occurred. But that's something we have to look at," she said.

Here's the most thorough explanation yet for the train derailment in East Palestine

Notice how in that last snippet we’ve changed from explaining past cause & effect to speculating about the future?

This is a prediction, which is also a kind of causal argument.

In this next snippet, a safety researcher predicts that adding vibration sensors would also have helped:

The vibration of a failing bearing, Tarawneh says, often begins intensifying thousands of miles before a catastrophic failure. So his team created sensors that can be placed on board each rail car, near the bearing, to continuously monitor its vibration throughout its travels.

“If you put an accelerometer on a bearing and you’re monitoring the vibration levels, the minute a defect happens in the bearing, the accelerometer will sense an increase in vibration, and that could be, in many cases, up to 100,000 miles before the bearing actually fails,” he said.

“It would have detected the problem months before this happened,” he said. “There wouldn’t have been a derailment.”

Hot box detectors didn’t stop the East Palestine derailment

Should we add vibration sensors to all the trains?

That would be a proposal argument, which we'll talk about later!

To recap

Causal arguments explain how and why something happened in the past, or will happen in the future.
Causal arguments rely on cause & effect reasoning about the links between events.
The language and presentation of those links can be explicit or implicit, but the underlying reasoning needs to be there.

Some events are caused by a sequential chain of earlier events.

Other events are caused by multiple factors that contribute at different times and to different degrees.

What do you think was the case with the train derailment?

It's a mix of both:

You could argue that reduced maintenance, spacing of the hot-boxes, corporate safety policy, and a lack of vibration sensors were all factors that contributed to the derailment.
Among those factors, you could then argue that reduced maintenance led directly to a damaged wheel-bearing going into service, which led to overheating, which led to mechanical failure, which led to the derailment.

So you can see that this particular situation involved a complex combination of linear & factorial cause & effect.

To wrap up this activity, why don’t you quickly summarise your take on why the train in East Palestine derailed?

Don’t make things up for this one. Just use what you’ve learned about the story from this page (and any other sources you might have read), and briefly note how one event led to another.

(Use explicit cause & effect language where you can!)

Summarise the pattern of cause & effect that led to the East Palestine train derailment.

Seven types of argument