Never knew that the shape of the wheels and the tracks were that important. Always thought just the flanges were responsible for the steering. Very clearly explained for me who has no degree in math. Thank you👊🤗

This is a broadly correct but simplified explanation. Some extra details: the wheel profile is not really semi-conical; it is a complex hyperbolic transition into the flange. But at first glance it looks like a conical shape. The inside camber (angle) of the rails is necessary to prevent the "conical" shape of the wheel set exerting an excessive lateral force onto the rails, which would otherwise tend to be pushed apart. Two interesting effects can actually be heard; one is where the train has come to a near standstill on a curve with superelevation which is normally designed for higher speeds. Then the wheel-set is not sitting in quite the right position on the track, and one wheel starts to slip with stiction, giving an audible shuddering noise. The other audible effect is where the curve is so tight that the flange comes into action: this results in a sharp metallic (& loud!) squealing sound. This is usually at slow entry & exit sections into / out of stations and switch yards. To minimise flange wear, automatic grease pump stations on the track are often employed at these sections, which only grease the _inside_ surface of the rail where the flange makes contact, but not the running surface of the rail (you don't want grease on _top_ of the railhead).

Wonder how these massive steel wheels are quieter than car tires moving over steel tracks at 160-200 mph. Might be interesting to hear a train engineer give detailed explanation why high speed train is relatively very quiet from inside. Freight train moving 30-40 mph is very noisy standing outside. We are talking about bullet trains.

That’s as long as the wheel profile matches the curve radius. Once the radius gets tighter, the flanges come into effect and you will hear flange squeal. Also, the flanges are what guides the trains through turnouts aka switches.

6:15 The solution in short: As the railway turns (let's say to the right), the rails slightly move to one direction (to the right), but the wheels want to roll straight because of their momentum. As the wheels are semi-conical, the contact position between wheel and railway is shifted (to the left) and that creates a semi-conical rotation, where the wheel automatically roll to the side (to the right) and takes the curve.

I was working on the central line (London underground) when they got the new trains, the wheels were designed differently to what the old stock ran on which resulted in the tracks getting worn... Large sections had to be shut down at a time to replace the track. We weren't privy to the possible upgrade of the wheel set up but this video is interesting.

I don’t know why i am watching this at 3am but it’s quite fascinating to understand rail working

Well explained , shows us that it was almost impossible to find out by ourselves how that all worked actually ! and it started already in the nineteenth century with all the machines needed to produce such fine pieces ... wonderful !

When I was a kid, I did a lot of research on this. Out in the “road,” the wheels act like this, steering themselves. I had hung around with a switching crew for a summer. The most incredible parts were where the curves were so sharp, that the wheels squealed and the flanges were taking over the job. I always found this fascinating to the point that had some railroad had taken a chance on me, I would have made a career out of it. Well, I got stuck in a construction and trucking job where I was sometimes working in the worst of conditions. They had no clue. Their loss, not mine!

Thank you for adding what would happen at the end if the smaller conical shape were on the outside rather than the inside. I'd been trying to imagine it as you were describing the correct configuration.

i started my engineering career with rail support maintenance and was so surprised as how this occurs. Cars and locomotive trucks must be re-turned to put that profile, as well as the rail. specialized equipment is used periodically to regrind the rails. amazing!

Very nicely explained. Many times I wondered how rigidely connected wheels, in the absence of a differential manages to negotitate curves without slippage. Your clipping cleared all my doubts. Thank you sir.

I live near railroad tracks, often walk near them and never noticed all this. Thanks.

An amazing animation and clear explanation. I've never thought simple - actually, as I've learnt today, by far not so simple - rail tracks and wheels require this much sophisticated design. Thank you so much for this video. I've found it just by accident but now I'm looking forward to watching the previous ones, too.

Been wondering about how this works for years. Puzzle solved. Thanks!

even a blind can understood clearly.... thank you.... well described... ❤️

This channel deserves 10M subs

Always knew that the wheels were slightly conical but this demo makes the actual physics of the conical shape easily understood, before when I was explaining that train wheels were slightly offset the ones I was talking with couldn’t really believe me but now I’ve got something that explains it better than I can

Now I have learned something I didnt know anything about, and that I have never even thought could be an issue in rail engineering. Thank you!

this should be taught in schools...very good. thanks

What an amazing explanation! The graphics you created specially to explain the mechanics behind the design of rail tracks and wheels is so very effective and appreciable. The way you have explained the whole thing is so easy to understand. This is how complex concepts need to be taught. Three cheers!

Such a video voiced by an actual human with a firm grasp of the English language would be much appreciated.

Excellent - semi conical shape wheels - railway track -rails trigonometry mathematics calculation -centrifugal force - application - simply superb

MAN that was a LOT of math!!!! I took train wheels for granted, but now I wonder who in the world came up with all this knowledge. I mean it is ridiculous. It’s a “simple”…wheel but it’s not! SOOOOOOOO cool to even get a GLIMPSE of the engineering involved!

You give the basics, but it's more involved than that. Without restraints on the wheel set, the forces that tend to centre the wheelset tend to cause it to overshoot and then hunting occurs where the wheelset shunts back and forth laterally. This phenomenon was extensively researched by British Rail scientists in the 70s and the science of self steering established. Up to this point it had never really been investigated properly. It then became possible to design the wheelset suspension to remove the hunting and for true self steering to be established. Eventually, it was found that the wheel flanges had rusted on the inside as they had played no part in steering the vehicle ! The BR scientists nicknamed them "the crash barriers". Of course, once the curve exceeds a certain value of "tightness" as in yards and sidings, self steering is not possible, and the flanges guide the vehicle accompanied by much squealing as wheels skid on the rails.

The track system is basically the same since it started. That says a lot for the inventor.

very informative and very beautifully explained. never realised that the flanges are slightly conical. thank you.

Terima kasih kawanku telah berbagi informasinya

Lots of good information but I'm left with questions (in case they do any revisions). The graphics for the force vectors are all drawn by someone who didn't understand that the length of each vector is proportional to its magnitude. The big resultant should be the diagonal within a rectangle and the horizontal component is the short side of that rectangle while the vertical component (resisting gravity in this case) is the long side. Next, I kept asking what keeps the wheel from getting so far to the side to have the flange touch the rail to make that squealing sound we all dislike (the sound that every Bostonian at Gov't Center hates). The video leaves the stability question only half-answered. Then there is the purpose to all that random, irregular thump, thump, thumping. Also, was this written by a person who made dozens of grammar errors or a computer who writes, mostly correctly, what it hears - leaving those errors untouched?

Excellent explanation. I used to know different explanation, you have clarified with correct information. Thanks 🙂

I knew about this but I had trouble explaining it. Now I can direct folks to this website. Many thanx!

This is good old engineering explained with today's excellent graphics. Hats off to those engineers from the Industrial Revolution.

Lucid explanation...very well done...now I understand the Amtrak lurching and long period sway at high speed. Good stuff!

The ratio of triangle (sin and cos) explanation finally made me understand! Assume hypotenuse is constant (non changing). Any angle change set by the wheel at that point in time changes the horizontal and vertical (ratio of opposite and adjacent over hypotenuse). But since hypotenuse is constant only the other sides change length and the length is equal to the force!

Thank you for your most valuable lesson about the act of a railroad train. It convinces me more that railroad trains are not driven: they are only operated by engineers and other train operators. This lesson teaches me how flange wheels make slivering sounds when the wheels turn according to the bend of the rails.⭐🌟

I feel like I was just taught railroad mechanics by an Indian. Thanks Chief!

this does a good job of explaining this but I wonder why it is so difficult for engineering types to use articles properly.

Keep making videos about train stuff.. I love these

Wonderful friend and good explanation.thamk you

Genius old engineering! Thanks for an excellent explanation!

Great video and very educational!! Thank you! 🙂🙂🙂

Thanks to the animation creator and who explained the physics. Excellent presentation.

I understand the differential effect and camber angles in automotive steering. This video makes complete sense, very good!

U explained me a 200 pages book in 8 minutes . You're Amazing bro, Try to make people understand everything in this world keep it up 👍

Whomever figured all this out in the first place was a genius. I've loved railways all my life and I just learned this today.

Very interesting and makes sense. Can or has someone explained the cross anchor bogie which improves curve handling.

No words 😂😂😂😂 amazing views of railway wheel mechanism

The animation is super that anybody can understand easily, Railway Engineering is my favorite I like it from my childhood my father always took me to railway line and everything stated practically, I miss him always May Allah give him on highest position in paradise aameen❤❤🙏

Very nicely explained! Thank you very much!

the vector components at 4:20 are typically demonstrated by drawing a rectangle with F as the diagonal, and the components as the height and width of the rectangle.

Wow!! .....Engineers ........you guys who designed this out of the principles of physics ....are the real deal!!

Awesome 3D Spectogram Explanation

This seems to be only partially true. For certain, the semi-conicity of the trail wheels helps keep them centered on the rails without the flanges doing all the work. But the part of this video that tries to describe both wheels on an axle as acting purely like a large truncated cone is at least somewhat specious. Even if this effect was entirely accurate, it does not explain how the wheels always follow curved tracks regardless of other forces (not mentioned in this video). Also not mentioned is that on modern trains, each bogie also steers passively, and the flanges definitely help the bogies reorient themselves to keep the wheels best aligned with the rails. In short, this video makes a good point, but the overattributes the affect as if it is the ONLY thing contributing to the train's steering.

Irrespective of a few extremely minor flaws...it's an excellent explanation on something I did not know before 👍👍👍👍👍

It is one of the best explanations i have ever encluntered on this topic. I wish they would teach the same way in school, colleges, and universities. Thank you very much for making this wonderful video

No one thought a train had a steering mechanism…. 0:05

Was this known at the outset of rail roading, or was it developed through trial and error?

Very good excellent explanation as well as animation.

Excellent presentation. Very well explained. I learned something new today. Thank you.

very clear explanation. Is the same principle at work in two-wheeler counter-steering?

The animator blew it when showing the vertical and horizontal components of the perpendicular force. The horizontal were typically shown much too large and the vertical too small.

A Lovely engineering systems,

Excellent demonstration and explanation .Thank you,Sir .Vetri South Africa 🙏🇿🇦🙏

wooow

What you don't mention is that the wooden ties on curves are subjected to a lot of wear. My college professor in Wood Products Engineering used to say that the Southern Pacific railroad didn't use creosote treated ties on their curved sections because the ties wore out so quickly from stress and vibration and needed to be replaced so frequently that the extra cost of treatment wasn't worth it.

Interesting vidio i do understand now how it works realy...... Omar from mombasa kenya.

Cool to watch I built wheel sets for trains for a living. Very cool.

I like your exclamations very much . they say using rails instead of trucks to transport goods. I think I heard once that once the wheels are moving it will keep going and slow down eventually. In that case it will uses less fuel pre mile. Doesn't need as much fuel because these heavy structures won't stop so easily just like a bowling ball.. could make a video and possibly to tell us what forces are at play there. Just started watching like your programs very much. many of us appreciate it

If they are going to take the time to explain the concept through detailed graphics and animations, why not put a little more time into getting the grammar right and maybe using a real human to provide the narration?

Very useful and important session ❤❤

And this is why you need people with good attention to detail.

The train knows where it is at all times. It knows this because it knows where it isn't.

The singular vs plural and the lack of using articles in the text of this was very distracting i realize it was a computer generated voice but damn

Amazing that the design hasn't really changed for more than 100 years.

ගොඩක් වැදගත් හුගක් දේවල් දැන ගත්තා?👍🇱🇰

There is no such thing as centrifugal force. There is centripetal force, which is tangential, not radial. This is high school physics. Rails are not tilted inwards: the tops are ground to match the conicity of the wheels. When you said 'we already said ...', you hadn't. You didn't mention that the bogeys can swivel w.r.t. the carriage. You left out about a thousand 'the's. Please don't perpetrate misinformation or illiteracy.

Fascinating , now I'm gonna research Conics thanks !!!

That was mind blowing explanation i haven’t seen before 👏👏

I am thinking this same subject. So very Excellent explaination. Good 👍👍

Thank you for explaining this principle in such lucid and easy manner. Much appreciated!!

Excellent information.

Absolutely perfect explanation! My compliments!

fascinating. very well explained

the title of the video is the smartest catch, otherwise there are plenty of similar videos i skipped past talking of engg., wheels etc.. This video must have also told who designed and showed confidence to run tonns of humans on such precise calculation to probably micrometres.

Great Information, very well explained Thanks

Sounds like Kevin Malone narrating. “WHY WASTE TIME SAY LOT WORD WHEN FEW WORD DO TRICK”

This would be a great Test Question to solve in Class. Always enjoy see practical examples of math/trig in the real world. Nice work.

Very comprehensively explained. Good job. Thanks.

You are a great engineer, excellent presentation ❤

❤❤ this is really good explanation 💯 bro

Great education

Good and scientific explanation. Never thought about that.

In high-school, I never gave a damn about circumferential diameters. Now in my late 20’s I can’t get enough of them.

Thank you for the imp. useful and amazing interesting ಇನ್ಫಾರ್ಮಶನ್.. Hats off❄️to mechanical engineering & science

Very nicely explained with superb animation. I can relate it well being a science student butit was very well explained that a layman can understand well

KZfaq recommended this video while I was thinking this problem on a city train. Well done KZfaq

Very interesting

@0:35 "Thus, train weight is supported by yhe wheels." -NO SHIT GENIUS

Thanks for video, one more thing to mention is one rail higher then other on curve. 😊

I first learned this when I used an r46 train for my Roblox game.