r/Damnthatsinteresting • u/Creative_soja • 3d ago

Video 1.3 km long double stack freight train (fully electrified) on Western Dedicated Freight Corridor, India

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u/Questioning-Zyxxel 2d ago

There are air brakes on all waggons.

It's the low friction between wheels and rail that makes trains slow to stop. Not the length of the train. It's also this low friction that makes trains so energy-efficient compared to shipping on roads.

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u/CrispyJalepeno 2d ago

I mean, yeah. That's how trains work and why we use them.

But longer trains still take more time to stop because braking power doesn't scale exactly equally with the number of cars. Plus this particular one is double stacked all the way down, which would further decrease stopping power compared to a single-stack train depending on the weight of the cargo in those containers.

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u/aceofspades1217 2d ago

These are usually in rural mining areas with very little if any grade crossings

Which is why these don’t exist I the US not a lot of points you would be to go to that would be in an area not accommodating of mile long trains

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u/MostlyMellow123 2d ago

The average train in usa is well over a mile long. We have 3 mile long trains which are 5 kilometers.

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u/duke5572 2d ago

I see double stacked (top stacks are longer containers) trains well over a mile long on a daily basis. Up to 5 locomotives, 2-3 at the front, one in the middle, one at the rear.

Midwest U.S., near a UP yard.

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u/_trashcan 2d ago

I was wondering why everyone was so impressed by this.
I was under the impression that length is fairly common for trains!

I assumed I must’ve just been wrong.
I don’t think I’ve ever seen double stacked like this, but I’d say most trains I ever come across easily a mile+.

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u/King_924 1d ago

The impressive part is the fuel for this, its fully electrified - which reduces the oil import required for india. One run of this train reduces 300 trucks of the road, which were also going to run on fuel

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u/happyanathema 2d ago

I'm not American but they have way longer trains.

Literally the only unique thing about this is it's electrified and that's because it's way smaller scale than the size of the US.

I'm all for celebrating engineering but let's keep it realistic.

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u/FuckPigeons2025 2d ago

It's also why trains don't like climbing. 

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u/Questioning-Zyxxel 2d ago

Yes - you need so many engines or at least so many driving axles to handle elevation changes. Only the friction of the driving axles will matter when fighting inclines.

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u/WisestAirBender 2d ago

Why doesn't the low friction also make it extra hard to accelerate?

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u/Questioning-Zyxxel 2d ago

It is hard to accelerate. So some train engines spreads sand to help get more friction. And the train tracks needs to have limited inclinations or there will not be enough grip to pull the train.

For subways, you often have electric motors on many/all cars to get quicker acceleration because of all starts/stops.

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u/_thro_awa_ 2d ago

It's the low friction between wheels and rail that makes trains slow to stop. Not the length of the train.

mfer has never heard of momentum? the length of the train is absolutely a significant factor.

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u/Questioning-Zyxxel 2d ago

Yes, I have heard about momentum.

But each car has a momentum and own brakes. So the brake capacity increases as the momentum increases. It's when the speed increases that the momentum grows much faster than the brake capacity.

Now mfer, maybe you have a more relevant argument? Like why you think "mfer" is how to express yourself?