Which Is Easier To Pull? (Railcars vs. Road Cars)

[@PracticalEngineeringChannel]

🪒Henson Razor makes a great holiday gift: bit.ly/3CWiWJP 👷Other cool Practical Engineering stuff here: store.practical.engineering

[@lourias]

I appreciate that your videos can appeal to audiences at least as young as 8 years old. You do not dumb it down, rather you use the technical term and explain that technical term. How awesome is that? I love physics, math, sciences of all sorts. I attempt to instill that into my grandchildren. My 8yr old g-son, who is in gifted and talented program really loves abstract and tangible concepts. You bring both of these ideas to your videos. Please continue such awesomeness!

[@Messilegend1000]

Hey Grady! My nephew loves trains, he LOVES talking all day about trains. Say, he were to have the life goal of working around trains, should I teach him maths? Is that a good start? I mean, is algebra (or some special kind of maths, sorry I am just a blue collar mom doing her best) helpful for him? Sorry for the strange question. Love love love your videos, we watch it together!! )))

[@LivinSouthern]

A channel on KZbin I watch, Hyce, that also included some of this information is here is a link to one of his Railroad 101 videos kzbin.info/www/bejne/oIC6pWyEo9iCjq8si=IQDe9L27W_vU7Bu9

[@ADHJkvsNgsMBbTQe]

+1 for Henson. I don’t think I will ever go back to disposable razors 🪒🙂 I wish they would make a travel case for their product. Maybe you could put in a word with them.

[@Big_Un]

Great video again as always. Thank you! A bit of feedback, if I may, on your sponsor Henson. I believe it will be relevant to other viewers. (It turns out positive, promise! LOL) I bought a Henson a while back but every time I tried to use it I felt it was a terrible and uncomfortable shave and ended up switching back to my 5 blade, flexible head, disposable razors. I just resigned myself to dealing with the constant clogging of the disposable blades and wonky cartridge/handle connection every time I tapped the razor in the sink. With the disposable razor, the flexible head adjusts to the optimum angle of the blades against my skin. I didn't have to think of the angle that I held the razor in my hand. In my opinion, there IS a learning curve to using a Henson, but it makes ALL the difference! Once I got the optimum angle correct, the Henson is by far a better shave. If any of your viewers have struggled with this as I have, I encourage them to keep at it. It will be worth the effort. One other tip, making the shaving cream a little wetter while using the Henson also makes a big difference. Hope this helps someone.

[@infa7615]

It's so heartwarming to see a civil engineer overcome their greatest fear and make a video all about something that moves

[@bartsanders1553]

This is the most wholesome dis I've ever seen😂

[@loscheninmotion9920]

Amazing comment

[@NoNameAtAll2]

his* he's alone

[@techheck3358]

@@NoNameAtAll2the word their is singular too 😊

[@personator]

​@@NoNameAtAll2 they're referring to a generic, unknown civil engineer, not a specific one. The generic 'they' is valid.

[@katieandkevinsears7724]

I'm a locomotive engineer. I've moved many stone trains. In fact, in 21 years, I've hauled pretty much anything you can imagine...including elephants. I chose the level path without the tunnel. It's the longest, therefore I get paid more to drive the train.

[@seneca983]

I'd imagine that depending on the length it might also result in difficult working hours.

[@geraldfrost4710]

LoL! Maximize operator prifit!

[@Comm0ut]

@@geraldfrost4710 Considering the way modern US railroads treat employees, good for them getting theirs.

[@A-Milkdromeda-Laniakea-Hominid]

Now that's some decent application of mathematics and logic 👍🏻

[@TheEDFLegacy]

Elephants?! Neat! ...Did you need to use the horn when you had them on board? 😅

[@darkstar8827]

I used to be the manager of a warehouse that had a rail spur for shipments. Many times, I had to move the box cars by myself. I used a 'Johnny Bar' to start them moving, and then I could just push them into place at the docks, fully loaded. No problem, IF THE BRAKE WAS OFF.

[@RandymanB]

I did the same when I was a receiving department manager at a furniture store. I used my Chevy Blazer and a chain. The first time I did it my crew was saying no way I could pull the loaded rail car. I hooked it up, put it in drive and didn't have to add much throttle and the car started rolling. We were able to spot at the correct door for unloading.

[@lizj5740]

@@RandymanB *stop

[@seanworkman431]

Those brakes are there for a reason.

[@TimothyReeves]

Spiral tunnels? Wow, that's something I didn't know existed. All makes sense but it's cool to learn.

[@seanworkman431]

@@TimothyReeves railways are fascinating, the creative engineering is something to behold.

[@PennerFab]

I work as a freight train conductor in Canada, and the largest train I've had was 36500 tons of potash. It was 256 cars and 4 locomotives. It was two locos on the head end, one in the middle and one at the tail. Very rare occasion they run a train that big.

[@c44-9w9]

You work for cn?

[@codemiesterbeats]

Lawd have mercy there is a joke in here somewhere 😅

[@10C45E]

Amazing! I went to Canada and got to see for myself how enormous the freight trains are over there! It was my first time seeing a North American freight train in person and the photos really don't do it justice!

[@atomlib]

It used to happen more often in the past whenever yo momma had to visit the town.

[@sleepdeep305]

Whoops, you accidentally went over the 8-bit integer limit

[@hoodglasses8237]

I find these videos utterly fascinating. When I show them to my dad, who's worked for the Union Pacific for 25 years? "I just got off work. I don't want to look at trains."

[@Kroooza]

lmao

[@EShirako]

Can't always win. :)

[@DB-thats-me]

The rail wagon you were trying to pull had cold bearings. This makes a huge difference. A cold train has a 'dead’ feel to it whilst, an hours running later, the same train will feel much more ‘lively’. Not as pronounced on an all roller bearing train but on old white metal bearings, can add an extra notch or two to maintain speed.

[@IndyJay53]

Wow, that's so interesting!

[@hanshima_]

Thanks for sharing. I have been working on railway for some few years, and I didn't know about that yet.

[@DB-thats-me]

@@hanshima_ Thankfully KiwiRail has done away with ‘free’ shunting and moved to push pull. I have worked in flat yards where roller bearing wagons can start to roll due to wind pressure alone! We called them ghost wagons and they made NO noise. Good way to get yourself killed if you didn’t keep your wits about you when out in the yard.

[@Island_Line_Rail_Productions]

They are CARS not wagons

[@DB-thats-me]

@@Island_Line_Rail_Productions OK. Well done. 👍. My comment was in relation to the bearings, not necessarily what rides on them.

[@whyjnot420]

The most impactful practical example of what happens when friction is low for me was seeing just how easy it was to move stones that weighed several tons while they were being suspended by an excavator (we were building a retaining wall). It truly is amazing just how much friction matters.

[@PascalGienger]

I was allowed once in Germany to push a train with 4 carriages on a even track. I was able myself - only myself! - to push the train slowly to motion using my fuil body weight and muscles. It began to move! With a truck - no chance. Railroads are so energy efficient!

[@dustinbrueggemann1875]

@@PascalGienger If not for the whims of financiers, trains would be the only way freight ever moved. There's simply no arguing with the fact trains just need less to do more in every single critical category.

[@rob585]

@@dustinbrueggemann1875What holds them back is maneuverability. It’s too expensive to lay track to every single customer and trains can’t make as tight turns or go to as small places as trucks do. Trains are good for moving a lot long distance. When you need to move a small amount to a specific destination however, the train makes a lot less sense than a truck.

[@Nauda999]

And gravity matters too, how easy is to move anything in the space, you wouldn't believe.

[@garethbaus5471]

​@@rob585That is true, but we use trucks for extremely long repetitive trips far more often than we should.

[@AL_O0]

This reminds me of a demo i saw in a museum, they had a truck axle on asphalt and a train axle on a rail, both with a pull rope, and despite the train one weighing more than twice the truck's, they were noticeably easier to pull

[@honkhonk8009]

demoman. Gravel. TF2

[@benjurqunov]

I move full railcars around our siding with basicaly a 6' crowbar.

[@eriklarson9137]

@@honkhonk8009 rolabouta. Ice. MG6

[@glenmccabe3364]

They demo this concept for kids at the train museum in Tokyo. They put 10kg of water (20 x 500ml bottles IIRC) trays x 4 of them on a carpet, rubber wheels, rollers and steel wheels IIRC. Even to adults, it's amazing how much easier the steel wheel trays are to push.

[@AL_O0]

@@glenmccabe3364 This was a full size train axle and wheels weighing 1.4 Tons on standard gauge track and children were still able to move it relatively easily

[@kevinyancey958]

I had a teacher, back when I was in 5th grade, who tried to move a rail car with a tractor. The tractor's tires just spun in place. He was stymied and thought it impossible. Another man handed him a steel bar, with an angled foot on one end, and said to use that. My teacher looked at the man and thought he was nuts. He stuck that foot in between the wheel and rail and put a bit of pressure on it and the rail car began rolling. It was the prime example of a lever for teaching our class.

[@lorenblaine5275]

When my daughter was in preschool they were learning about simple machines (LEVER, pulley, screw, inclined plane, wedge,wheel) At home I set up a 10 foot plank with a fulcrum (block) very close to the wheel of my one-ton truck. She was able to lift the tire off the ground just enough to see completely under the tire. Apparently she told the class and I became the "cool dad" 😎 whenever I was there helping out.

[@DB-thats-me]

I suspect that between using the tractor and using the Johnson bar…..someone released the handbrake! 😳😂 Old trick. Like sending the new guy to the stores for a long weight. 👍

[@patrickday4206]

Fulcrum would approve

[@NorwegianKnifeDude]

I'm a train driver from Europe, and I found this super interesting and informative! When we occasionally had to move cars manually we used long steel bar chisels (not sure what its name is in English. Basically a 5 foot crowbar) as a lever under the wheels to get it rolling. Thanks for the video! Will definitely check out more of these!

[@mack.attack]

We call them Johnson bars or Jonny bars 🙂

[@johnrhodez6829]

If you had attached the cable to the locomotive with no slack in it and the sat in the middle of of the cable to car would have moved. As a ten stone teenager I once sat on the mooring line of the Queen Mary when it was at Southampton, very slowly the line went down to the ground. I stood up and the line went slowly up again. That ship was somewhat heavier than the railcar!!

[@christopherhammond9467]

@@mack.attack or outside of the train community we call them breaker bars for concrete work

[@jaredkelly930]

​@@mack.attackmexican switch engines

[@feedbackzaloop]

Before watching was wondering how the question so simple needs a video this long for an answer. But now I see, it has never been about the answer, but the journey to it.

[@sorryplease5071]

That’s the fun. 🎉

[@bobsykes]

I love this series. These concepts makes sense intuitively, but the numbers are amazing! I hope you keep this going for a really long time. There’s so much I’d like to know about how railroads work and how they operate. Please include ones on the various propulsion systems in use in different types of trains these days. It must have been the biggest day in your son’s life helping Dad pull a car! Cheers!

[@thithi8793]

ok

[@lycu3093]

ok

[@heartofdawn2341]

Working in a stockroom/yard and the difference in rolling resistance between smooth, hard concrete and soft, grippy asphalt often makes the difference between being able to move a heavy pallet by hand with a pallet jack, or needing to get the forklift. And with a pallet jack, keeping the floor clean is all too important; a small stone, nail, or sliver of wood from the pallet itself can make a easy load impossible to move. The flip side is this; a smooth, hard and clean surface makes things much easier to move but much harder to stop. Without rolling resistance to slow things down, you have to deal with all of the inertia yourself.

[@Wetcorps]

I often find myself handling my pallet jack with as few stops as possible, because the hardest part is to get it moving. Today I learned it's called static resistance, neat.

[@Vinemaple]

Wheelbarrows work the same way: it's always easier to push along the path than to cross open ground, no matter how flat.

[@cr10001]

Tyre pressure *really* makes a big difference to the rolling resistance of my car. I can tell almost instantly if a tyre is a bit low, by pushing it on my driveway. By the way, at 5:00, Grady forgot to mention that on electrified lines, most of the downhill force can be recovered by regenerative braking and fed back into the grid. And Grady pulling a wagon by hand brings to mind No 1111, 'Four Aces', a 4-8-4 steam loco built by Alco in 1930 for the Timken Roller Bearing Co to demonstrate the lower friction of roller bearings. At some stops, for publicity purposes, three men could pull this 300-ton locomotive.

[@mandowarrior123]

Topping out your tyre pressure is always worth it before a long journey for fuel efficiency, and tyre wear. Also, waxing to reduce skin drag is very valuable if you do more than local slow driving.

[@helplmchoking]

Not just the resistance, though a couple psi low will make a real difference on a long journey. I had some body work done on my car and for whatever reason the shop kindly 'checked' my tyre pressure. ~32psi is a good rule of thumb for low performance economy cars on thick tyres, which is what they set mine too even though I run 35f/38r and the difference was *instantly* noticeable just leaving their shop. The ride was squidgy, the handling numb and less predictable, and the grip just felt wrong. IMO everyone should have just a simple pressure gauge in the car, give them a quick check regularly and make sure to keep them topped up especially on a journey. A couple thousand Km when you're 5psi too low and you'll notice how bad the tyre wear is

[@frederickjeremy]

I’ve been an inland merchant mariner for almost 20 years, an engineer for my company for almost a decade now. I love your presentation on this. I would love to see you do one on our industry that works somewhat behind the curtain, but in plain view. One thing i have learned is it it more cost effective per unit to move something in larger quantity. As a rule of thumb our boats burn one gallon of diesel per horsepower used per 24 hours run time. It is hard to think of something that burns 12,000 gallons of diesel per day as economical, but when you figure in the amount of work done for that fuel it absolutely makes sense. Id love to see you break it down. I do believe that our inland waterways provide the lowest resistance to moving large quantities of stuff in this country.

[@jovetj]

The common rule of thumb promoted by the railroads has been: one gallon of diesel fuel will move one ton of freight for 400-500 miles.

[@joshyoung1440]

"One thing I have learned is it is more cost effective per unit to move something in greater quantity." No offense but it didn't really take you a career in shipping to "learn" that, did it?

[@joshyoung1440]

Also it is very easy to think of something that burns 12,000 gallons as economical because the amount is obviously meaningless; it is the ratio that determines efficiency, which you had already told us about, rendering the number 12,000 irrelevant. Other people also understand that efficiency is based on proportion. You're kinda speaking down to people.

[@jaelwyn]

​@joshyoung1440 To learn to observe that it is "usually" true, probably not. To learn _by how much_, on the other hand...

[@davidhawkey8426]

My grandfather ran his own a trackwork company for many years. He did work all over the Midwest. I was only about 8 years old when he retired so i never got to learn much about his work, but I love these videos about trains because they remind me of my grandpa. ❤

[@weylinwest9505]

Nothing's better than a railroader grandpa.✊

[@AaronLyNxAI]

I grew up by train tracks till i was about 8, and this reminded me of him. My grandpa didn't work on trains, he was a roofer that couldn't read or write but could roof a house in half the time a crew could and it would look just as good if not better. Dude could also ride a horse like a 20 year old. Miss the old fella. Wish he could see me today making knives, and building things just the way he would have wanted 😊

[@witzman]

Time to get into 18xx boardgames

[@AaronLyNxAI]

@witzman nah for trains, the best thing ever is derail valley/Railroads Online. Both are awesome steam Loco games about laying the track, and driving the trains, with some decent physics.

[@RCAvhstape]

@@weylinwest9505I have a railroader uncle. Worked for Penn Central and then Conrail in the 1970s, working on tracks, bridges and tunnels out in the middle of nowhere, real back breaking work. Creosote burns on his skin from railroad ties. He's retired now but loved the railroad and got me some pretty cool toys when I was little. Lionel trainsets, etc. Took me and my dad out into the hills to show us some of the stuff he'd worked on or seen.

[@JasonTrew2018]

I'll use an example, until 2001, Norfolk Southern ran down Saluda Grade and that was at the time the most steepest with 5% going down. From the summit at Salula all the way down to Melrose, trains had to use dynamic brakes to keep the trains at around 8 MPH and if you didn't keep it at around 8, you would be heading for the runaway ramp down at Melrose and you might get in some trouble (that is why you had the Road Foreman of Engines on board and he had a special key just for running trains down Saluda Grade)

[@JustAGamerA]

Dynamics and air the whole way down, with retainers on

[@RCAvhstape]

5% sounds like a roller coaster.

[@bwhog]

There's a reason that it took so long to build the railroad across the Sierra Nevada mountain range when the first tracks were laid. Grade is everything and failed brakes have caused a lot of problems!

[@billmoran3812]

Great video! Having worked for the railroad I can tell you that in the engine shop it was not uncommon for two or three guys to actually push a locomotive on level flat track. One person could keep it moving once the static resistance was overcome.

[@cedricrummell5986]

I can second this, in our locomotive shop we use a dinky forklift to nudge locomotives without having to fetch a running one.

[@AwoudeX]

@@cedricrummell5986 we used a bar specially shaped to move cars with ease, up to 6 at the same time

[@cedricrummell5986]

@@AwoudeX was it some form of "pinch bar" that you use under the wheels?

[@AwoudeX]

@@cedricrummell5986 yes

[@cedricrummell5986]

@AwoudeX wow I never would have guessed you could move 6 cars with one of those.

[@JuhanaSiren]

15:20 a roller bearing car can be relatively easily moved manually, but plain bearings take quite a lot of force to get started. The railroad I volunteer at hosted a strongman competition with a boxcar pulling competition as one event. Our crew moved the car around with a locomotive just before each attempt to get a layer of grease in the bearings, otherwise even the strongest competitor couldn't have budged the car.

[@jaredlancaster4137]

If you were wondering, the amount of rolling resistance from a cars tires is extremely dependent on tire pressure, tire type, and surface type. When i had my 3500lb jeep on stiff load range e tires with 80psi on a smooth shop floor, it literally took one finger to push. Now try pushing the same jeep but on more flexible four ply tires, underinflated at say 15psi, on a gravel road. Itll probably take two people. Pushing cars with flat tires is very very difficult.

[@ariochiv]

I smiled to see the kiddy car behind the "grocery hauler", and even more delighted a few moments later to see its "owner" in action. A nice touch.

[@dyadica7151]

I would like to have seen, at the very end, an illustration of the diesel fuel needed per ton/mile to transport that gravel by truck compared to by train. Otherwise, excellent video, as always.

[@ThZuao]

Idk about the truck part, but a train needs roughly 1L of diesel to take 1 ton of cargo 500km.

[@AlexanderBurgers]

​@@ThZuao Rough back of the napkin math says a truck takes easily 20 times more. Most of that will be in the rolling resistance, some of it in air drag, and some in not having to deal with vehicle traffic nearly as much.

[@joeyager8479]

Trains measure in at 477 ton-miles per gallon of fuel vs trucks at 145 ton-miles mostly due to reduced rolling resistance of steel on steel vs rubber tires on pavement and wind resistance. This info was from a Stanford University study dated 12/16/2022. A lot of info is available off the net if you figure out how to phrase the question so that Google actually is a help!

[@Rich-on6fe]

One ton pickup probably 50 to 100 litres

[@dyadica7151]

@@joeyager8479 So Grady could have shows 1&2/3 teaspoons of fuel in one hand, and 1/3 of a cup of fuel in the other to show the difference to move a ton of gravel one mile. I think that, or perhaps the amounts for the initial room-full of gravel to make that visual impact.

[@warman5066]

I remember when I worked at a railroad, if you didn't have the brake set, the engine would usually start to roll away, even on seemingly flat surfaces. Later, when I worked on rail transit, there was a spot that seemed flat but the train would start to roll if you released the brakes, and it just so happend to be on paved access way. Out of curiosity, I stopped a truck in that spot and put it in neutral and had no roll back.

[@jaredlancaster4137]

Especially on loose and uneven surfaces, it's impressive how much of a hill I can leave my car on in neutral and it's won't roll.

[@xe-wf5iv]

@@jaredlancaster4137 That is less do with friction and more to do with the fact that most cars are designed not to roll.

[@jaredlancaster4137]

@@xe-wf5iv actually I'm pretty sure cars are meant to roll, generally with low friction.

[@satunnainenkatselija4478]

Obviously, you can't push rolling stock uphill manually. So the answer depends on the gradient.

[@godfreypoon5148]

@@xe-wf5ivNot sure which car companies you've been hanging around.

[@nadnerb2k]

With the curved path - you might want to look at: 1: superelevation of track - the practice of tilting the track, with the outside rail if the curve being higher than the inside rail, to assist with the reduction of drag around curves 2: flange lubrication. In the USA, locomotives usually apply grease to their flanges automatically on curves. There are also track-based lubrication systems. Cuts noise and drag. Lubrication is usually applied to the inside of the curve, just below the running surface of the rail. 3: self-steering bogies/trucks. Modern trains, usually passenger vehicles, can physically turn the train wheels within the bogies to line them up with the curve. 4: Tilting trains. Active mechanisms on higher speed passenger trains to get faster travel around curves. E.g: Acela has active tilting above 60mph in some areas. 5: load/length restrictions on curves 6: the risk of "string lining"

[@duck8dodgers]

You should totally do a deep dive on canal and river barge shipping too. I'm not just saying that because I'm constantly seeing crazy amounts of gravel shipped up the Hudson River from where I work, but that is part of it. I would love to see how the barges stack up against the trains.

[@destructionator17]

I came back to this comment section to say exactly this. I know a barge can hold more weight than several train cars and they say it is more fuel efficient but I'd love to see the force meter on a heavy load pulled by hand too.

[@MikeV8652]

As a knowledgeable railway historian and railfan/techno-scholar, I appreciate how well you explained this for the masses.

[@Matthew-pn1qu]

🤓

[@mijyadoc5374]

hahaha, that's a good one MikeV8652.... but come join us down here in the masses for tonight we celebrate this event by sharing a special chocolate cake no matter the class or ranking. You do love a good chocolate cake, right?

[@ducvuong-qt7bp]

zzz

[@beefyj4597]

I agree, this video was very well explained. Keep following your passion Mike

[@majesticeagle5461]

This is not something I have ever cared about for a second in my life before, yet now I’m fully invested in this, that’s how you know you’re doing something right with your videos

[@jovetj]

This is the stuff us train nuts appreciate about trains! The physics involved is kinda mindblowing, yet amazing.

[@majesticeagle5461]

@@jovetj lmao I only read “train nuts” when I saw the notification so I thought you were talking about those truck nuts but for trains😭😭😭 This is very interesting though :)

[@erich930]

In flight school, pushing planes by hand is a common occurrence. They weigh about 2000 pounds empty, but I’m always surprised at how “easy” it is to keep them moving. Id be very interested to see how the rolling resistance compares to a street car and a rail car

[@Kandralla]

For a plane it's going to be similar to a car. There's little reason to optimize there because the plane spends so little time running on it's wheels and any weight/volume added to accommodate rolling resistance is going to hurt your in flight efficiency.

[@mrl0gic]

@@Kandrallaplanes have small tires with very high inflation pressure. low rolling resistance is easy if you don't need to handle rough terrain and provide a smooth ride

[@Kandralla]

@@mrl0gic lots of road vehicles are going to have high inflation pressures. The rolling resistance is still going to be more like a car than a train.

[@thekinginyellow1744]

@@Kandralla I'm going to respectfully disagree. Aircraft tires are designed for a different set of circumstances than those of road going vehicles. They have a much smaller contact patch and much less flex. Furthermore they are not connected to a drive train the way at least two of an automobiles tires are. Not having to spin two axles, a differential, a driveshaft, and part of a clutch is going to reduce friction even further. To just dismiss this without actually running the numbers is foolish.

[@Kandralla]

@@thekinginyellow1744 I can guarantee that no company is spending any effort worrying about the efficiency of aircraft tires. I can also guarantee you that they are closer to road vehicle tires in terms of rolling resistance than not. You don't have to run numbers. You just have to look at the materials and know a tiny bit about their applications.

[@TheOneEyedSpaceChimp]

Honest question: You said "In a perfect world, a wheel is a frictionless device." but doesn't a wheel require friction to impart forward momentum?

[@Lucas_McToucas]

the drive wheels should have just enough friction to get it moving at the desired speed, but all wheels are used in braking

[@wiley-harris-anderson]

Maybe he means the friction between the axle and the wheel?

[@lezzbmm]

*rolling resistance* / *rolling friction* is how easily a car rolls on a surface w/o braking or accelerating - this is mostly stuff like the bearings not being perfect (having a nonzero coefficient of friction) and the wheels themselves continuously deforming as they get squeezed by the ground as they rotate which uses some energy and heats the wheels and wears them out from stress this is a parasitic friction this is a separate friction from *traction* where u r sending driving force thru the wheels via the friction btwn the wheel and the road/track surface (where u r looking at a classic high school «“coefficient of static friction (btwn the wheel and the road/track” * normal force of the weight ok the axle» type situation)

[@ValhallaIronworks]

The key word here is "device". The wheel device itself is ideally frictionless. So not including what the wheel is rolling on.

[@turbinex_generators]

PLEASE do a pro and con video on, diesel electric train VS. Battery electric train. Try to give as much information as you can. In my opinion that would be a great video.

[@TonyA552]

If you haven't already done so I'd be interested to learn more about pipelines and how efficient they are at moving liquids as opposed to using rail cars.

[@tamtri6218]

ok

[@vasaaviarion]

oooo good idea. now I'm curious

[@genevarailfan3909]

Most of us have probably shipped things by rail without knowing it, by ordering things online. We don't normally get told how it's being shipped, but UPS and FedEx ship a lot on high-priority trains. I once had a package tracker give me a series of locations along BNSF's northern mainline!

[@scottfw7169]

And if the thing ordered was manufactured in another country it could well have gone from seaport to wholesaler/distributor by rail.

[@yuwtze]

@@scottfw7169 Yep. When I bought a new car, it was shipped by sea to a port, then by rail to a facility near the auto dealer. Unfortunately, they don't give out tracking anymore, but the dealer staff said they used to be able to watch the tracking as the train made its way across the country.

[@EngineerLewis]

In the UK we almost never use distributed power on freight trains but our trains are very short compared to US ones, usually a maximum of 30 waggons/cars. I have been interested in US freight trains as they demonstrate the way a few engines can pull a huge amount of material. In the UK the HS2 project build of our newest London to the Midlands train route are using freight trains to carry materials to minimise trucks on the roads during the build of this railway.

[@FTW23-qq8nb]

Multiple Unit (MU) control is very cool, I wonder if future trains might get electromechanical brakes. And on the matter of brakes it is possible to out brake the wheels by using eddy-current brakes acting directly on the rails.

[@Railman1225]

Honestly, I think our freight trains have gotten TOO long! I miss the days when our mainline freights were only ~75 cars, instead of the average 110+ today. We need to go back to shorter trains, whether that's by convincing the railroads, or making them with train length limits.

[@PanduPoluan]

The reason why long freight trains are common in the USA is because of the sheer size of the country. At such distances, the savings due to low rolling resistance is totally worth it.

[@Philip271828]

@@PanduPoluan It wouldn't be worth having a train that long here, by the time it would have finished departing it would be arriving.

[@mikefochtman7164]

Well, as with many businesses, some of it is pure economics. There is a 'fixed cost per train' in crews, scheduling, and coordinating. Then there is a 'variable cost' that rises with each car/waggon. The length also has some discrete 'jumps' in cost when another locomotive needs to be added. And of course the market demand. Some goods like coal to a power plant, or other bulk items to one delivery point versus pickup/ dropoff off cars all along the route. Finding the 'best fit' can be quite a challenge. (there was even a game that used this sort of economic challenge, "Railroad Tycoon" I think it was called)

[@johnstreet797]

Grady your channel is my second most favorite thing in Texas, behind my son. Since I have entered my second childhood you explaining things in a way an eight year old can grasp is extremely helpful. Muchas gracias amigo.

[@OldieBugger]

I'm less than 2 minutes in this video and I'm totally committed to listen to it very carefully. I love this talk about real-world problems, and the solutions thereof.

[@mikefochtman7164]

I've always loved trains and love this series. From an economics point of view, you can pay up front for the railway of a train vs. roadway for simple trucking, or you can pay the higher operating costs of trucking. This is why specific point-to-point shipping can be so much cheaper in the long run by rail. A well-defined route that will be used between only a few points can justify the higher costs of building the rail line. Whereas when you need a lot of flexibility to get to many locations, like end point delivery of packages, cheaper roads win out. Really some interesting stuff.

[@verdiss7487]

Generally speaking, building a mile of rail is less expensive than building a mile of highway. Costs vary a lot but the general estimate is $1-$2 million per mile of rail, and $2-$3 million per mile of 2 lane road. Maintenance is even cheaper, with refurbishing rail in the $100,000-$300,000 per mile and road at over $1 million per mile.

[@codeman99-dev]

@@verdiss7487Refurbishing costs for rail vary widely. Repair / maintenance of rail is what prevents the existing network on the east coast from improving. Just search for "Amtrak repair costs"

[@davidgervais5974]

@@verdiss7487 I believe you're neglecting the part where you have to prepare the terrain with tunnels and bridges in order to install the railway.

[@Pang-nn4eq]

Trains also are not subsidized as much as rubber tire transport. Trucking freight literally makes zero sense economically. It's the largest industry in terms of subsidy there can be. We're destroying the environment, city landscapes and people's lungs with one single economic imperfection.

[@IvanStepaniuk]

There is a VERY sad story about this. In the context of a TV contest in Young, Uruguay, the crowd was pulling from an old train to try to get it to move. It eventually started rolling but they could not stop it. Eight people died.

[@hugoballs2133]

natural selection is a thing

[@Monkey_D_Luffy56]

Wait seriously? Where can I find some information about this??

[@IvanStepaniuk]

@@Monkey_D_Luffy56 Wikipedia has an article (only in the Spanish one) as "Tragedia de Young"

[@murphychris9811]

well dont be dopes and try and pull a train car with out thinking how to stop it

[@Railman1225]

Probably why in those old videos of railroads showing how easy a locomotive rolls by having people pull it forward/backward, they most likely still had an engineer in the cab to work the brakes. Trying to move something unmanned is NEVER a good idea. Just ask my older sister. Her car had started developing power problems, as in it wasn't propelling the vehicle anymore, at least not very quickly, so it was parked in the driveway for a while. Then, she wanted to move it into the garage, and I volunteered to help. Before we started pushing, my sister decided it would be a good idea to have the car in gear to help us up the hill, which wasn't a bad idea, per se. Not being in the driver's seat during that, however? *_O h y e s ._* Soon as the car reached the flat floor of the garage, it no longer was working as hard against gravity, and suddenly pulled away from us. She tried to get back in the seat, but unfortunately she couldn't in time, and the car crashed right into the door linking the house. Our mom was pretty upset, and justifiably so, especially since the house was a rental. Even after fixing it ourselves, when we moved out a little while later, that accident kept her from getting her deposit back. Moral of the story: never try to move a vehicle _completely_ uncontrolled.

[@mr.coolaid1004]

Its amazing to see the engineering side of railroads and locomotives when my father and his father have collectively spent over 100 years working for BNSF working as conductors combining my love of engineering and my home life.

[@paradiseranch2421]

You are really hitting it out of the park Grady! Absolutely love this series, cannot wait for the next video, thank you so much for putting so much work and time into these videos

[@Texas_and_Pacific]

Another thing to consider is that on a curve, the driving wheels in the locomotive have more surface area contact with the rail, reducing the locomotive’s traction and making the chances of stalling out greater

[@ThunderChasers]

I've been to the TTM a few times. My late friend, Jim Helmke used to volunteer there. Really cool to see it featured on the channel.

[@PracticalEngineeringChannel]

Those guys are a lot of fun.

[@davidroddini1512]

So good that he stayed “on track” when talking about locomotives. I think it would be disastrous if his “train of thought” was derailed.

[@dewiz9596]

That’s a five out of ten 😊

[@happytrails5342]

🚪 🚶

[@weylinwest9505]

​@@happytrails5342It was time for Thomas to leave. He had seen everything.

[@happytrails5342]

@@weylinwest9505 😂

[@balboa9439]

Yup. He rolled with that one. That's a wrap.

[@morg52]

At the Minnesota Transportation Museum, I shoved a loaded boxcar by hand quite easily. I got it started using a tool with a six foot long handle, that sits on the rail and pushes against the wheel. ( with a lever and a fulcrum I can move the world!) Then just pushed the boxcar about thirty feet, pushing with my body. The boxcar had the old style bearings with an oil bath and babbitt bearings. The bearings on the car you tried to push were modern roller bearings, if you had just put more consistent effort into moving it you would have succeeded in moving it.

[@darkstar8827]

It would have moved easier if the track was level.

[@BlueGamingRage]

It would have moved easier if he were stronger, too

[@sirduckington5641]

Hi Grady. I'm almost done with my engineering degree and I just wanted to say thankyou! I have learned so much of the iintuitive thinkingand logic behind how the real world works from years of coming across your videos, almost more than i have at uni. Sure ive learned how to put the physics down on paper and how to calculate/read the more nuanced things like S-N curves, etc. But the basic logical understanding comes from real world examples like this and I just wanted to say, thankyou, thankyou, THANKYOU!! For doing it. Not jsut for me but so that everyone who watches these videos can learn a little bit about how the world works"

[@ryguy8675309]

You are the Bob Ross of Civil Engineering. I mean that with the highest praise, as someone who is such a master of their craft that they can teach it to anyone in a way that makes sense. Bravo sir!

[@RazingthenRaising]

I know a retired railroad executive. He told me once that anyone can get a (even fully loaded) railroad car moving with just an ounce or two of force. Stopping it, however, is a different matter all together!

[@grandinosour]

I remember seeing a television commercial where a Ford truck would pull a train car to show it had power.

[@darkstar8827]

I saw that one, only it was a chevy!😁@@grandinosour

[@RazingthenRaising]

@@grandinosour Yep. The new electric truck. The problem is, they used a tow strap that proved absolutely nothing. It could only handle about a ton of load. Those of us who understood totally and completely laughed.

[@nekomasteryoutube3232]

9:38 I love how your little kid was trying to help dad move a car. Thats cute

[@fredflintstone8048]

The fact is that a locomotive, or series of locomotives cannot pull the entire train from a stand still. This is why there is play (slop or lash) in the couplings and why they back up the train first to take up all the lash in the couplings. Then they begin to go forward they're only pulling the first car, and then the second, etc. When the last car begins it's motion the train has good momentum and can continue.

[@Island_Line_Rail_Productions]

If you can, it is not always possible to start a train with the slack run in. A train can still be slacked out and be able to start moving

[@admiralcapn]

Another advantage of trains (especially at higher speeds) is the relatively lower air resistance compared to buses or trucks (depending on if you're moving people or stuff). With all the cars in line with each other, the first locomotive takes most of the air resistance and other cars get some drafting benefit. This is most easily seen in the perfectly contoured coaches of high speed rail.

[@tylerodonnell-paccione7523]

I recognized that museum immediately! I unfortunately don't live in the area anymore as I've been corrupted by the world of narrow gauge railroading, volunteering as a fireman on old D&RG steam engines, and my brain started buffering when you were talking about maximums of 0.5% grades and 12 degree curves, since I'm used to 4 or 5% grades and 30 degree curves

[@andywomack3414]

10:00 One of my jobs as a railway clerk back in the day when train tonnages were figured using an adding machine, we'd add seven tons per car to account for rolling resistance.

[@Beryllahawk]

Great video, I laughed aloud at the bits of humor. And your helper is Maximum Adorable! I was really astonished that you could move your car like that, and even MORE astonished to understand the forces are so similar even though the rail car is so much bigger! This really made clear just why (and how) trains are so much more efficient within what they can do. I was also kinda proud of myself for looking at your little three track options illustration and going immediately for the tunnel-and-bridge choice. I've learned from you! I wouldn't mind a deep dive series on tunnels later on, myself. I've been on a passenger train just once, but along the route we traveled through THE tunnel that John Henry helped build. And the city I live in is a literal railway hub, so I hear trains all the time, and our downtown area is laced with tracks. Heck, there's even the Rails to Trails program here, where they've taken sections of old, retired rail track and transformed them into paved paths for bikes and hiking. It's truly been fun already watching this series, and I've learned a lot too!

[@andrewreynolds4949]

That air resistance factor is a significant part of why you don’t see freight trains operating over about 80 mph very often. Beyond that range it starts to significantly impact the efficiency rail freight offers.

[@EpicATrain]

Technology Connections made a reference to your Practical Construction videos in their "Back-up beepers" video!

[@J3scribe]

I've been waiting for this video, or one like it. Thanks Grady! Steel on steel offers the least rolling resistance one can find without introducing exotic materials like Teflon, or whatever. The Chicago & North Western's mainline between Chicago (Elmhurst, IL) and Fremont, Nebraska never exceeds a 1% grade. That was by design. CNW and successor Union Pacific assign ½ horsepower per ton on the route for a typical freight train. More if they want to go fast, like a Z train. The movement of trains is so efficient it almost defies common logic. Railfans love the Big Boy and swoon over its power and tractive effort, but it weighs a million and a half pounds and is an absolute glutton when it comes to fuel. A couple of GEVOs or 70ACes weigh less and have more tractive effort. And they are so fuel efficient that the EPA rates railroads as only 2% contributors to greenhouse gases.

[@jovetj]

My hometown is on the Blair Sub!

[@dontarguewithidiots7459]

GREAT video. I would have never have guessed the rolling resistance if the train car would be only 50 lbs..

[@douglasengle2704]

This was good! I like discussions on the physics of trains! I never heard a discussion on how much the joints in railroad tracks can add momentary high resistance, it's obvious when thought about and can be seen. On curvy track the total degree of curvature per mile is used to give an estimate of power required along with the ruling grade. Even though gentler curves of 3° have a lot less resistance than 8° curve the 3° curve has a longer duration. I haven't seen if the relationship is near straight line linear. The range of curvatures encountered on a typical track appears to be close enough to treat it as such. A 3° curve is considered to be a the limit for standard gauge track where the conical shape of the railroad wheels will compensate for the inner and outer curve lengths. A narrow gauge railroad benefits by having the rails closer together and hence the inner and outer rails are closer in curve length. Rail-Trails are popular for bicycle paths and there is a mathematical power budget relationship between bicycles and freight trains. Studies in the 1930s concluded a healthy 20 year old male can generate about 1/10th of a horsepower for 10 minutes before needing to recover somewhat. At 170 pounds for the rider and 30 pounds for the bicycle that is 1/10th hp for 200 pounds or 1hp/ton. In the late 1800's studies on the minimal needed horsepower to start a freight train on level tangent track concluded it was 1hp/ton. After over coming the stiction of the friction bearings especially when some were using animal fat that nearly instantly became more liquid with the start of an axle turn and other factors the train would then typically accelerate to 12 mph. Which is fast enough for many heavy haul freight where there is not other trains waiting to use the track. Both modes of travel really need more horsepower to work effectively. Practiced cyclists measure their power output in Watts and generate 100 - 140 Watts over a grade (74.57 Watts to 1/10hp). ( My thermodynamic instructor took a lot off because on an exam pushed for time I used 750 watts to the HP and giving me an F. I retook the class and got an A at a different school). Freight trains today seem to run at 3 - 4 hp/ton. The extreme torque AC locomotive traction motors can generate without burning up like their DC counter parts allows those locomotives to start trains with just 0.4hp/ton as reported for Black River Basin coal trains. Steam locomotives were better at low speed continues grades hauling freight than DC Diesel electric locomotives because steam locomotives can run all day at a grinding 8 mph at full throttle and don't mind heat, while DC Diesel electric locomotives hate heat and at high throttle at speeds below about 12 mph will overheat and shutdown after 10 - 15 minutes. A lot of the fascination for steam locomotives comes from their intense visual display and sounds laboring at these slow speeds. The intense complexity of the display and sound greatly disappears at higher speeds. Every stroke of the side rods at slow speeds can be seen to push the train forward. The exhaust sound says what the locomotive is doing with great detail. The GE U23 Diesel electric locomotive, meaning 2300 hp, had such badly designed trucks they would not get traction at starting speeds and would quickly overheat and shutdown on continues long grades, leaving the EMDs on their knees pulling coal trains through the West Virginia New River Gorge where we used to rail fan when going to WV Tech, Montgomery, WV mid 1980s.

[@MrCubsfan3]

I took advantage of the Henson offer about 4 months ago and I LOVE the razor. The machining quality is excellent and I truly love it. (This is not a bot or anything, I promise - I'm just a satisfied customer!)

[@stephanweinberger]

@7:35 it's not just the energy consumption that goes up. Another reason to avoid tight curves is the additional wear & tear on the wheels and rails (all that squealing ends up being fine steel dust), which requires more frequent/expensive maintenance. Sometimes rail operators try to reduce that by adding lubrication devices, that squirt grease onto the wheel flanges of passing trains, but this also adds additional maintenance cost, and it makes the rails more slippery, which in turn reduces the weight the engines can pull (and brake) before the wheels start to slip. Over the years all that can easily add up to where a tunnel would have been cheaper. At least if you frequently run heavy trains; if there is only little traffic and/or light vehicles you can get away with it - so even the anticipated traffic patterns on the line will affect the route. An example from where I live: Here in Austria we are currently building the Semmering Base Tunnel to replace/augment the historic route over the mountain. The mountain line suffers from severe limitations in capacity, and not just because heavy trains have to get additional engines (or be split up altogether); it turns out that one of the main reasons for the reduced capacity is that the tight curves require constant maintenance. Only for about 100 days of the year both tracks are continuously usable; so despite being technically two tracks it almost has to be operated like a single track line for more than 2/3rds of the year. And fun fact: the original designer of the line even pondered a base tunnel himself, but this just wasn't technically feasible in the 1850s.

[@mikefochtman7164]

Oh, and I LOVE how your 'little helper' tried to help out moving your car. And his little car was a lot easier. Sweet!

[@leoblento6]

You can easily get the car moving with a cowbar. Just put it between the wheel and the track in an angle and press it down. And next time they need to move the old car around for a few minutes. The grease gets to its place at the right temperature. Newer cars got different bearings, they are easier to get move.

[@andresgustavoperezsarmient9554]

It never stops amazing me how better you get with each video at explaining the different topics

[@Yakhashe]

Also - in a dynamic scenario - there is resistance depending on acceleration. The obvious one is F = m*a, but the less obvious one is the force needed to get the wheels, axles and motors spinnng. I.E. to get a wheel running along a track, you need to accelerate it not only in a linear fashion but also bring it up to speed rotation-wise! So pulling a train (or car for that matter) and change its velocity is way harder than pulling it at a constant speed.

[@Kaziklu]

Fuel isn't really used to move most locomotives in the US. Electricity is. North America just doesn't want to build the electrical lines over the freight lines to allow for that electricity to be from potentially cleaner grid. So the Trains have the Diesel Generators to power the Locomotives. Generally due to upfront cost and remote maintenance. I only make this distinction because many modern Diesel Electric Locomotives can actually be converted to other types of generation...(though at some significant level of cost) or even a hybrid over head/generator operation if the will existed to allow them to run off multiple sources of electricity without changing the drive system. A Full Diesel Locomotive wouldn't have that ability without a significantly larger cost level.

[@john762x51]

I don't normally comment on someone's sponsorships, I do actually feel pretty strongly on this one. it is definitely worth switching to the safety razor the blades So much cheaper and actually last much longer And actually far easier to get than you would think. And you can actually clean them and dry them properly, which means you also cleaner more hygienic shave. I've never used this brand razor but But it does look really nice. And to be honest I've never had any problems with any of the brands of safety razor I've used So I would be Very confident in it.

[@MrFliffi]

7:59 that backdrop was my home town of cologne germany :D

[@nicklanders5178]

I think it’s interesting to include some of the differences between diesel and electric locomotives, as electric trains can recover a lot of energy on downhill sections of track and are vastly more efficient because of this

[@Deebz270]

I like how he 'stays on track'... And that the kind of workout he does, is on a calculator... Nice easy tuition, with applied wit.

[@wattheheck6010]

Today I recommended your channel to my neighbors who have an inquisitive 2-yr old boy; he is fascinated with all things that move. It's my effort to get kids interested in science. I hope you keep your videos rolling!

[@akokada973]

"so, I'll try to stay on track here" 8:17

[@Xanthopteryx]

Fun fact: LKAB (Swedish mining company) uses the worlds strongest electric locomotive to haul 750 meter long trains, total weight of 8.200 tonne. They use one (they are double locomotives), in the front of each train, and they run up to 20 trains every day. The type of locomotive is Iore. 10.800 kW. 1.400 kN starting force.

[@The901meister]

10,000 ton trains are quite common in the USA and lengths of 10,000 feet or more with as few as 2(4400 horsepower each) locomotives. Power can often be lower than 1 horsepower per ton.

[@Xanthopteryx]

@@The901meisterThe difference i think might be the environment they are driving in. Here some aerial views of the tracks: kzbin.info/www/bejne/j4XWf2CEhLytqNk And here a nice night view of the train: kzbin.info/www/bejne/j2bIhZWOfLFgpsU The track is roughly 500 km long.

[@jonathanjones35]

This was a really cool segment. I would have loved to see you try and pull a modern, roller-bearing equipped car such as a hopper or double-stack. I'll bet it would take a fraction of the force and that you probably could have gotten it rolling yourself. Interestingly enough, there is a famous photo taken by the New York Central Railroad back in the day, that shows four your women pulling a huge, modern steam locomotive (a 4-8-4 Niagara class) equipped with roller bearings. The photo demonstrates your points well. Thanks for this video. I love your work.

[@cr10001]

Was that a NYC Niagara or 'Four Aces' no 1111, built by Alco for Timken as a demonstrator? Because Timken used to carry out 'stunts' like that to demonstrate the low friction of their roller bearings. I note that Alco also built the NYC Niagaras so there was probably a family resemblance.

[@jonathanjones35]

It was a Niagara.@@cr10001

[@jonathanjones35]

You can do a search for: "four girls pull a Niagara locomotive" and you'll find it.

[@jacobbacuetes9850]

I'm a Railway Engineering student, I'm loving these series so far! Thanks! Also locomotives are awesome!

[@joesomebody3365]

These are excellent videos for helping to understand why railways are more efficient with bulk/heavy loads. I like this video and the demonstration of the railroad wheel shape videos a lot, thanks for including real life demonstrations as part of your presentation. (Showing you being able to move such a huge rail car with just your own strength and a rope helps to understand just how much more efficient it is to move something on a rail platform energy output wise).

[@bradliston8990]

Thanks Grady, now when I hear those trains at 4 in the morning I'll be a little less upset knowing how much fuel they're helping save. lol

[@ErikMoad]

I can see how the production quality of your videos have increased, without sacrificing personality. Keep up the great work!

[@wyattr7982]

Fantastic series, would love to see you dive into electrification as well!

[@noahzinc]

I was looking for a comment like this. Regenerative braking on downhill grades could be great (or maybe not, I’m no engineer).

[@noahzinc]

I don’t know if it would be feasible (extra cost and complexity) but it seems like a good idea to add batteries and motors to each rail car to distribute the pushing as well as the regenerative braking (as well as weight).

[@georgobergfell]

Newer electric locomotives in Europe can transfer the energy that is recovered by regenerative braking back into the overhead catenary system.

[@stephanieparker1250]

That would be interesting!

[@Tjthemedic]

While it's common in the imperial system to use lb-force, it's actually pretty rare for kg-force to be used in metric contexts. Newtons and kilonewtons are much more commonly preferred.

[@christopherscholz]

Thank you for this. I made peace with use of lb-force and I am glad to hear that I am not the only one who cringes every time kg-force comes up.

[@hobartspitz1029]

Great video! I think there are some additional things about trains that your viewers might like to hear you explain in a video. In general, passenger trains and freight trains have significant differences. Passenger trains have non-slack couplers and start from a dead stop. Freight trains have slackable couplers and mostly do not start from a dead stop. Slackable couplers have three states: Stretched, slack, and a bunched/compressed. Stretched couplers are under tension and transmit forward/acceleration force from car to car. Slack coulpers don't transmit force between cars. Bunched couplers are compressed to their shortest length, and tranmit force backward/breaking force from car to car. (I'm simplifying to the general case a bit.) Unsually, a train can't start from a dead start and the procedure is as follews: The locomotive(s) operate in reverse until the last car moves a bit. This bunches all the couplers. Then the locomotive(s) move forward, accelerating one car at time, and each car's momentum is added to that of the locamotive(s) and the previously accelerated cars. IMHO, there is about a second between the acceleration of one car and the next. That delay is what allows a freight train to start without pulling all cars at once. The industry expression is "If you can start it, you can move it."

[@timbert4672]

I've often wondered exactly how much force it takes to move a train car like that as I've seen it done so many times in these strongman contests, now I know so thank you. I once did a truck pull with several other people for a charity event, that tractor unit weighed somewhere in the region of 8 tons (metric) but once we got it moving it wasn't that hard. I wanted to try getting it to move more on my own once it was going (I couldn't shift it from a standstill on my own on tarmac) but as with you there wasn't really a safe way of doing it. We didn't have a force gauge handy but I have wondered how much it took.

[@tomholroyd7519]

I'm not sure a world without friction would be "perfect"

[@SystemDesignNepal]

It won't. You are correct.

[@azrobbins01]

I would love to see you talk about the linkage system for trains. Specifically, what prevents cars from yo-yo-ing in the middle when there are engines at each end. If they are being pulled from the front and pushed from the rear, won't there be some cars in the middle that are crashing back and forth in the slack?

[@J.C...]

There is no slack. It's a solid connection with no forward or aft movement.

[@azrobbins01]

@@J.C... When they hump the cars in the hump yard and they crash together, you can see the couplers giving in to the inertial impact. That movement is not like the ball pendulum desktop toy that shoves the engine forward as each car bumps into the line of cars. There are shock absorbers of springs that absorb some of the impact, and in a long line of cars that slack adds up. Imagine a 1 mile long train being pushed up a hill with the engines at the rear, and then compare that length to the same train being pulled up a hill with the engines at the front. I would imagine that the train being pushed up a hill from the rear would be at least 100 foot longer from all the slack between the cars and the shock absorbers/springs being compressed, vs stretched. In a train with engines at the front and rear, there will be some point in the middle where some cars are constantly chaining between being pulled and being pushed as the resistance on the track changes or wind friction or from changing gradients. Imagine stretching a slinky out on the floor very long and pulling on one end while pushing on the other, and then dragging it over an uneven floor like you would the train. There will be some point in the middle that is constantly changing between being pulled and being pushed. As this point changes along the train, those cars will be crashing into each other and constantly jostled about.

[@BattleshipOrion]

Depends on what your standard coupling devise & method is for your region. A TL:DR rundown is like this, there are two types, a "quick" coupler, and various types of "hook & loop" and "Knuckle". The lighter the car the more you have to worry about "string-lining", the heavier the car, the less so. Usually it's advised to put lighter cars at the rear, and heavier cars towards the front, like UPS/FedEx doubles & tripled here in the US. The lighter trailer (usually 28ft long) is always the rear most trailer. No, cars in the middle don't care about slack...the cargo does. Some cargo can only be put in specific cars with proper cushion cars. If you are in the US, next time you see a train, look for the ones marked "cushioned load", or have extended coupler boxes on the ends. With modern packing methods, they are becoming rare, some notable types for each US rail network is: Southern Pacific, Santa Fe, Chessie System, and Southern Railway (not the UK one). In addition, with the advent of Precision Scheduled Railroading (PSR) here in the US, you will sometimes find one or more engines on the head, mid-train as distributed power (DPU), and on the end, though prior, you'd see these types of combinations in mountainous regions, mostly head & end, but mid-train DPU did occur regularly.

[@Blazer02LS]

The engines are linked so that they speed up and slow down in a way that keeps as much slack out of the consist as possible. So if you see a consist with helper power that will commonly have the head engine running just slightly lower than the helper which keeps the slack tight. Then as the grade lessens they reverse roles a bit and the lead engine stretches the consist out as the helper slows down. For a consist with distributed power it dose a similar thing, the lead engine controls the slack by stretching the consist until the middle engines start moving, then they assist and pull the remainder of the consist behind them, basically 2 trains but running coupler to coupler.

[@Trump2PrisonOn34Counts]

@@J.C... Many broken knuckles are piled up outside the section office from engineers that had too much slack action and broke knuckles, draft gears, even car frames. I most earnestly assure you that slack action on a train is a significant force and must be in the awareness of the engineer at all times. The EU uses a sprung buffer which minimizes this but slack is still a factor even so.

[@dtvjho]

16:00 All those trucks not only cost energy, they require a lot of drivers 😊

[@HelloKittyFanMan]

I'm glad you say "IDEAL world" instead of "perfect world," since "PERFECT" is so much more drastic that it carries some much bigger implications about how our world will be if we have earned that level of glory, including so many of the things that will be so obsolete that they wouldn't even exist in it. At least "ideal" is a low enough standard that these things could conceivably still exist and be used, so it's a lot better a comparison against this realistically mortal (though temporary) world.

[@skwerlman4089]

I know you hinted at it with the mention of distributed power, but id love a deeper dive into intratrain forces, and the things that can go wrong when they arent managed appropriately (stringlining, buckling, etc)

[@kallestri3635]

You should have a look at the kiruna narvik line in northern Sweden/Norway it uses regenerative breaking (you can feed back power to the grid if your railway is elecrifed) when going to fast down hill, in fact this line is a net producer of power, since the ore moved from the high altitude at kiruna down to the sea in narvik, but you in the USA don't have that much of electrified railroad =(.

[@CookswellCoKenya]

good point i was going to say! clever swedes!

[@christosgeorgiafentis4825]

8:11 Please tell me that pun was intended. It was so good.

[@madscitechify]

Your content continues to be the highest tier of quality. Keep it up!

[@billbarnes1043]

As a side note, my son and I were both born in the same town that your Pullman cars were built in, Butter Pennsylvania. My son is a Tow Boat captain on the Mississippi River, each one of the barges in his tow holds 35 rail cars or 135 truck worth of material

[@andywomack3414]

6:55 "Listen closely..." No need to listen closely, the sound of a train negotiating curves can dominate the soundscape.

[@mudassirshaikh8662]

True bro, that shi kills your ears irl

[@mailleweaver]

I'd be interested in seeing how they maintain the railroad. How they repair floating tracks like at 10:54 would be a good example. All that flex must increase resistance to the trains passing and put a lot of strain on the rails.

[@scottfw7169]

Actually, a certain amount of flex is better than trying to keep the rails rigid. The rail flexes because the weight of the car and its load is concentrated there under the wheels and the flex allows that stress to be shared along a constantly moving distance of rail instead of a chain of single points. Now, true, as always there can be too much of a good thing. And then there's the thing about the ground itself flexing as the seasons change. And there is also the thing about the rails themselves stretching and contracting as the seasons change between hot and cold. The ballast gravel serves two major purposes; it allows rain water to flow through and away from the rails and crossties/sleepers, and its sharp crushed stone edges jam against each other and do just enough of a job of locking those same crossties in to place without locking them in place too rigidly. Every so often railroads will go through with specialized machinery which removes, cleans, and repacks the ballast stones.

[@sublivion5024]

⁠@@scottfw7169 no lol, rails are not designed to support the weight of trains like this - they’re designed to transfer the weight to the sleepers - and sleepers are not supposed to move. this is really bad and can be fixed with a tamping machine, by relaying the track or with some more ballast and manual tools.

[@sublivion5024]

most modern railways will have specialised trains called tampers specifically pack ballast tightly under sleepers, also having concrete sleepers instead of wood helps. this just looks very cheaply built and badly maintained.

[@juniperreborn7956]

Great video Grady, love your videos!

[@pfatful]

At 9:10 it's worth mentioning that a constant force would have resulted in acceleration not a constant speed so that actually makes sense

[@benlovett454]

I love how you treat your audience like they actually know something

[@kiefershanks4172]

It's neat that the force to pull a car is roughly equivalent to a rail car. That's actually insane. North America's biggest blunder was abandoning its once vast rail network in favor of cars and trucks.

[@RiDu-p4m]

Yes, you are right. that was the bigges mistake of USA. Now the whole country is dependant on the wastly inefficient and heavily dependent on oil transport. There is not a shadow of chance that USA will survive the closing peak oil.

[@AFNacapella]

12:21 new channel logo confirmed

[@frisosmit8920]

"The only working out I do is on a calculator". That one made me laugh

[@joshuakelso1680]

For real thank you for the lightweight bedtime reading, it’s exactly what I need

[@dustinsmith8341]

"In a perfect world, a wheel is a frictionless device" Sir, I thought you were an engineer.