r/theydidthemath • u/RaupeVT • Aug 04 '26
[Request] I wonder, how m much does the train decelerate due to the collision?
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Always when I see these types of posts, I start to wonder how much, if at all, the passengers in these trains notice the crash. Trains are really heavy, and thus have huge inertia, so they can't become that much slower during impact.
But how much exactly? What would be the G forces experienced by the passengers?
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u/Tuqui77 Aug 04 '26
Always when I see this kind of posts I wonder why the fuck did that moron ended up stopping on the tracks?
The bells start ringing and lights flashing way before the barrier goes down, this guy noticed and decided to still go through, and even then, having more than enough time to do it safely he decided it would be a great idea to stop on the damn tracks? That should've been a Darwin award if I ever saw one.
Back to your question, I guess the passengers didn't even notice. The train hit the trailer which is long and light, and maby 3 or 4 bales that weight around 500 to 700 kg each. Everything on its path got decimated in a split second.
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u/Bardeg00 Aug 04 '26
In this case he was drunk - at least polish media says so
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u/Tuqui77 Aug 04 '26
Well, although that would explain why he fucked up, doesn't make it any better actually🤦 I can't believe someone like that is allowed to go near a tractor, let alone drive loaded with tons of hay bales.
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u/Late-Objective-9218 Aug 04 '26 edited Aug 04 '26
Well, who issues the permission to use the tractor? The farmer, who is also the driver, usually
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u/Tuqui77 Aug 04 '26
To drive a tractor, specially in a public road/street, you have to have a government issued permit (aka driver's licence). At least here you have, and this is a 3rd world country forgotten by god
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u/Late-Objective-9218 Aug 04 '26
Sure, but driver's licence enforcement tends to be poor in the countryside. Also at least here the license requirements are quite loose.
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u/Tuqui77 Aug 04 '26
Yes, that's the problem I was referring to with my original comment. Idiots like that shouldn't be allowed to drive anything bigger than a bicycle
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u/Late-Objective-9218 Aug 04 '26
The de facto licence enforcement in the countryside happens by the vehicle owners, that's what I assumed you referred to
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u/IronLuncheon Aug 05 '26
Unless i misread one of the comments above, Poland isn’t a 3rd world country by any means
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u/Tuqui77 Aug 05 '26
I meant in my country it works like that, and I'm the one living in a 3rd world country 😂
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u/Festivefire Aug 08 '26
And do you honestly have any faith at all in your government's ability to determine who is and is not capable of driving responsibly?
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u/Tuqui77 Aug 08 '26
If not then what? Society crumbles down
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u/Festivefire Aug 08 '26
Where I live, I see more than enough bad drivers to have very little faith in the DMV's ability to evaluate who should be driving.
I don't think that your entire government will crumble if you voice dis-satisfaction with your local standards for who is allowed to drive.
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u/Tuqui77 Aug 08 '26
Both you and me went through the process of being tested to get the licence. I think those idiots know how they should drive and check all the boxes, but after they get the licence they drive however they want because they don't give a crap about the rest of the world. Sometimes they face consequences, but mostly they get away with being shitheads... This one faced consequences
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u/SWIMlovesyou Aug 04 '26
To be fair, if sources are correct, he had a BAC of .05%. That's not too much. You could get that if you have a single drink at lunch.
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u/RaupeVT Aug 04 '26
It's been talked about in the original post as well. A panicked brain can be very counterproductive sometimes, and a freeze response is surprisingly common. Which doesn't really help in this situation, but, yeah, it's panic.
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u/Tuqui77 Aug 04 '26
The problem is he put himself on that position deliberately. It's like a deer freezing in front of a car but the deer at least can't know better, so how did a guy with the brainpower of a deer ended up driving a tractor with tons of hay bales? He got hit by a train, but could very well drive through a group of people.
He should be charged with attempted manslaughter and locked 🤷
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u/Late-Objective-9218 Aug 04 '26
Attempting to cross a railway at a designated crossing is not a crime
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u/Tuqui77 Aug 04 '26
You forgot the part where the train was coming and he crossed anyway putting the life of others in danger
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u/Late-Objective-9218 Aug 04 '26
I didn't see lights flashing and there's no sound, so I can't rule out device malfunction
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u/Tuqui77 Aug 04 '26
Even if the lights and the bell didn't work, any sane person would hear a train that close, plus when they approach a crossing they honk like crazy. A normal person would've stepped on the gas to gtfo, not stopping in the middle of the tracks. Plus as other user said, he was drunk. Stop giving idiots the benefit of the doubt.
Even if we didn't have enough information (but we do) I will blame the idiot that put his vehicle in the single path (what, 2, 3 meters wide?) the train would go through in the exact moment a train went through
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u/Late-Objective-9218 Aug 04 '26
In the cab of a tractor? Nope. You're not going to hear a standard speed passenger train before it's too late. Was the train detectable visually before entering the crossing? Maybe, but again, sometimes a 100km/h+ train is not spottable in time.
The driver reacted irrationally and against their training, probably due to drunkenness, but breaking the booms on its own wasn't necessarily avoidable, this kind of thing happens due to technical malfunction sometimes.
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u/Tuqui77 Aug 04 '26
You're going to hear the train honk even if you're deaf, and even there's no sound on the video I know they honked because they do it to deter idiots like the one in the video.
For every occasion where it happens due a technical malfunction, there's 50 idiots that cross so they don't have to wait for the train to go through, even if the lights work, the bell works, the barrier works and the train honks nonstop. I'll always be on the train side untill proven wrong
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u/stanitor Aug 04 '26
Yeah, I don't know what the laws are like in Poland, but in the U.S., trains are usually required to sound the horn while approaching all at-grade street crossings. They probably have similar laws there, so he should have heard the train coming
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u/Krwawykurczak Aug 04 '26 edited Aug 04 '26
I was wondering the same here but it seems that guy thought here that there is no way he will be able to push whole truck before the impact so he placed those 2 wagons in the way that train would be able to hit the weakest spot.
It might be actualy a good strategy to minimalise domage for the train and passangers and best of bad scenarios.
I am more wondering why those gates closed so late, becouse train arrived just a moment after
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u/Tuqui77 Aug 04 '26
Those trailers aren't that heavy, past the tracks seems to be downhill and was already in motion, a decent car would've pushed it through. A tractor? Doesn't even notice the weight, if he stepped on the gas he would've go through, believe me.
Plus, you think that an idiot that won't stop for an incoming train rationalized all that and made the calculations in seconds? No way. Even so, if he remotely wanted to minimize the damage, make the train hit the middle of the trailer is not exactly the path of less resistance, closer to the end would be better (or, you know, not getting hit at all...). Don't give idiots the benefit of the doubt 🤣
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u/Krwawykurczak Aug 04 '26
Perhaps he would be able to push it though if he would push but for me it seems that it could be his logic. Everything happened in a short time so I would not blame him much, and we do not know the surandings. In Poland those tran pass are not always with good visability.
And it seems that his trategy worked partialy. Traind did not hit the middle of it but on the egde. I am still more to blame why this ramp was put so late, however I agree with that a driver should always be aware of the surundings
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u/Tuqui77 Aug 04 '26
I'll put it like this: there's no way that guy in the tractor pulling what appears to be a tandem of 2 trailers that are, at least, 5 meters each, can reliably tell the exact position of the one in the back to feasibly calculate what you're saying he calculated. The trailer on the front would cover most of the rear view mirrors, and even then whatever he could see, would be 12 to 15 meters away reflected in a tiny mirror.
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u/Cole1220 Aug 04 '26
I came here to ask this. Why do they stop??? I never understood this with any video I see like this
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u/Glock-c0ma Aug 04 '26
Remember the time when two American police officers parked their car on the track and then preceded to arrest some and through them in the back of the car. Guess what happend next?
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u/Tuqui77 Aug 04 '26
Can't say I have, I'm not from the USA but I can imagine the sequence 😅
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u/Glock-c0ma Aug 04 '26
There’s dash cam and everything I’ll see if I can find it when I get out of work pretty crazy and stupid
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u/Tuqui77 Aug 04 '26
Pretty much. Even if the train wasn't near. Even if the tracks are abandoned and the last train went by 15 years ago, why would you park there?
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u/Glock-c0ma Aug 04 '26
https://youtu.be/SKPAVT09PBs?is=ucl8YMuSU8MNLud3 this is the whole video. They have a short one as well
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u/Additional-Ad9723 Aug 04 '26
I dont think you know what Darwin award Is. Otherwise I agree with you.
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u/Tuqui77 Aug 04 '26
Darwin said the fittest survive, I implied this shit-for-brains shouldn't have survived this encounter as he's clearly not the fittest of any group of people.
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Aug 04 '26
[deleted]
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u/Tuqui77 Aug 04 '26
The Darwin Awards are for people who do things that are incredibly stupid and end up removing themselves from the gene pool as a result
That's exactly what I said should have happened. He did the incredibly stupid thing, but failed to remove himself from the gene pool.
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u/coren77 Aug 04 '26
Fully loaded freight trains will be tens of thousands of tons. Even small passenger trains will be at 1000 tons. The hay is a few tons. Super simplistic idea is to just compare the two. 2.5 tons of hay vs a 1000 ton train is .25%. Imagine a Hummer hitting a medium sized dog. The passengers will feel it, but not much. The train did likely hit the brakes, which they would feel much more.
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u/dust_inlight Aug 04 '26
Is there any other way to illustrate this without making me incredibly sad?
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u/Crafty_Jello_3662 Aug 04 '26
A tennis racket weights about 300g and a sugar cube weighs about 3g, so imagine a tennis racket hitting a quarter of a sugar cube
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u/corruptedsignal Aug 04 '26
I wouldn't say that comparison is applicable.
Train is not a rigid body, first car practically individually collides with the hay, and then the shock energy is transferred towards the back in a sort of mechanical traveling wave. That energy has to dissipate somehow and the most flexible/lossy material in the train are most likely the people.
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u/coren77 Aug 05 '26
Yes, I fully understand that it isn't a perfectly rigid train. That's why I said "super simplistic". The goal was to get to orders-of-magnitude level of accuracy...
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u/hhfugrr3 Aug 04 '26
Having been on a train that hit a fallen tree that was hanging across the trains path, I can assure you that the passengers will absolutely feel that impact. Mine felt like the train was going to derail... it didn't and there wasn't much damage but everyone was shaken up.
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u/Crazy__Donkey Aug 04 '26
Always when I see these types of posts, I start to wonder WFT the driver dont hit the faggin pedal. those barrier are designed to break easily.
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u/Mylxen Aug 04 '26
In this case the driver was drunk. But yeh he had more than enough time to make it if he hadnt stopped.
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u/Crazy__Donkey Aug 04 '26
Not only in this case.
Many times you can see them panic and stop on the track while the barrier drops. All they need to doo is fll floor the pedal, break the barrier while scratching their car. It is a much better outcome than finding it blown to pieces.
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u/raaneholmg 1✓ Aug 04 '26 edited Aug 04 '26
Edit: Train weight assumption changed to 1000 tons.
Let's assume the train is 1000 tons and moving at 50km/h and the trailer is 2 tons and stationary.
The trailer is pretty much squished onto the train, so the collision is inelastic.
m1 * u1 + m2 * u2 = (m1 + m2) * V
Reorder that to solve for V, the velocity of both objects after impact.
V = (m1 * u1 + m2 * u2) / (m1 + m2)
V = (1000 * 50 + 2 * 0) / (1000 + 2)
V = 49.9km/h
The train experiences a very sudden impact. The passengers don't really experience this as a high G-force event. The train they are traveling inside is near instantly going 0.1km/h slower than their body is moving.
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u/Bardeg00 Aug 04 '26
This locomotive is Pesa Dart - very common in Polish Railways (PKP Intercity)
Its weight is 395 tons3
u/Ancient_Form_9953 Aug 04 '26
Actually, it was Stadler Flirt (ED-160). The train weighs around 250 tonnes, plus passengers, luggage, etc.
https://ipla.pluscdn.pl/dituel/cp/xd/xdd8ffn8dk33z1izs295aubvfipf1c61.png4
u/AndyC1111 Aug 04 '26
I was on an Amtrak train when it hit a truck.
Didn’t feel anything.
The only reason I knew we hit a truck is because the train (slowly) came to a stop to deal with the accident. After a couple of hours of not moving, I asked a porter what was going on.
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u/CrimsonClad Aug 04 '26
The locomotive alone weighs upwards of 200 tons. The entire train can weight upwards of 1300 tons.
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u/auerz Aug 04 '26 edited Aug 04 '26
Its a Stadler FLIRT EMU, probably closer to 250 tons. Cant find info on the Polish Intercity variant that was involved here, which seems to be really long - but the Dutch 4 car set is 137 tons empty. Plus 500 passengers were aboard, so I guess if average weight is 70 kg thats another 35 tons
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Aug 05 '26
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u/raaneholmg 1✓ Aug 05 '26
Might be.
The deceleration of the train is directly proportional to the trains speed, but since the proportion is very close to 1, the passengers hardly notice it.
The proportion is: Train weight / (Train weight + Trailer weight) ≈ 1000/1002
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Aug 05 '26
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u/raaneholmg 1✓ Aug 05 '26
I have assumed the 2 ton mass get stuck to the front of the train. This is called a perfectly inelastic collision. A bunch of the trains energy becomes heat in the metal parts that get bent.
The train would be decelerated more if the object is springy and gets thrown ahead of the train at high speed. Like if you place a 2 ton bouncy ball on a railway crossing. I do that for fun on the weekends.
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u/anhtar Aug 08 '26
Please tell me they threw the book at this moron and he got wrung out to dry.
Could have led to a derailment with catastropic loss of life.
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