Trains’ Weirdly Massive Problem with Leaves

Video written by Amy Muller

[Kholdstare]

As a New Yorker I'm legit shocked we're innovating at anything dealing with our trains, good on us lmao

[adrukker]

Companion video: “Why planes need lasers: Planes’ weirdly massive problem with birds”

[JoeBleasdaleReal]

“Train cancelled because of leaves on the track” is one of the most frequently-used lazy punchlines in British stand-up comedy, along with “bus only arrives in threes” and “toaster always burns the bread”. Now, thanks to HAI, we know this is actually far more of a legit problem than Michael McIntyre would have you believe

[Renard]

Train driver here, it's crazy how slippery the track becomes when the right ammount of moisture meets crushed leaves (it's MUCH worse than snow or even ice)... A few years ago i approached a station very slowly, knowing the risks. I still had the first three cars overshoot the platform at crawling speed with the wheels locked, while the people on the platform cheered and laughed. You see, all the trains before me had failed to stop correctly at the platform and those people had come only to bet on how many cars would overshoot 😂 They made me laugh, which was very welcome because i wasn't too proud of myself 😅 Years earlier i missed a station entirely despite approaching very slowly. Fortunately there was only one passenger on the platform so i went back on foot to have her follow me to the train. That time the wheels were damaged and the difference between the distance measured by the wheels sensors and the track radar was so great that the onboard computer freaked out... If any train or tramway driver reads this, here's my pro tip: when it's extra slippery don't wait until you are under the magnetic brake trigger speed before you go into emergency. That's what got me both times as i was going very slowly and the magnets didn't trigger (static shock protection). 😒

[summit-development]

The leaves are simply built different. However, what you should really worry about is bricks. It only takes one brick to delay a train.

[victorrenevaldiviasoto]

I knew about that, leaves are a huge risk for motorcyclist, but I had never thought about that regarding trains.

[brianholmes]

Personally I think all trains should be equipped with lasers year round. not for track clearence, just because its cool. also to blow up that freight train causing my Amtrak delay.

[RonDLite]

I actually hold the patent for this! LRC (laser railway cleaning) which is for cleaning raiil by ablation. I built the first version in the Netherlands in 2014. Suprised to see it here. Anyone has a question I be happy to answer. I sold it because laying under a train is not my long term goal...

[anthonyholroyd]

As a conductor instructor working on passenger trains I can confirm that in 'leaf fall season' we run a different time table and drivers use special driving techniques to keep trains under control and avoid wheel flats, station overruns and signals passed at danger.

[barrel]

Fun little fact about wheels that are worn down flat; the FRA has a certain length requirement for damage like that. If the length of the flat spot is less than the maximum, railroads will often just leave the wheels alone and they round out over time as they’re used and experience normal wear and tear. This is why you’ll almost always hear that clacking sound when a train passes by.

[fabillo]

1:29 it should be a gigapascal of pressure, not force. One pascal is one newton per square meter and newton is the unit of force.

[kakahass]

I read the title as "We need lesser trains" and was I was ready to write an entire book in the comments about how we need more trains not less I think the stress from that cost me like a decade of my life.

[endor]

Well actually. Pascals are a measure of pressure not force. (love your work sam)

[timmccarthy]

As the Bible says, "A leaf does not fall without delaying British Rail"

[der.Schtefan]

I lived 6 years in Amsterdam. Everybody in the Netherlands use trains to commute to the next town. Whenever the first leaves fall, the whole country grinds to a halt.

[RyanTosh]

We're forgetting the real solution here: Have a guy lay down on a platform in front of the train, with their tongue on the rail. As the train moves, he will eat all the yummy leaf goo and we will be saved.

[baystated]

If Leaves find out about this and adapt, we could have an arms race on our hands.

[BenGroebe]

Couple corrections/thoughts: you'd want high (static) friction between the train wheels and tracks in all circumstances. Friction doesn't just allow the train to slow without sliding, it allows the train to accelerate without "spinning out." The lack of deformation of steel is useful for reducing rolling resistance, but you don't want low friction between the wheels and tracks ever, that's not where energy losses to friction are happening. Static friction causes no energy loss. Another reason you'd want to not have wheels sliding while braking is that it lengthens the stopping distance, since kinetic friction is weaker than static friction. Also, gigapascals are a measure of pressure, not force.

[bonelesswatermelon]

First we had Ghost Trains now Laser Trains. I wonder what the third installment in the trainlogy would be.

[georgeandrews]

Years ago, I interned at a place that made train parts. On a very boring afternoon, I overheard a few engineers in the next cubical talking about using lasers to get rid leaves on the track. I half thought they were joking, but apparently not.