@@Sugarsail1 Yes, when all else failed. Often though, the solution was circuitous routes that follow the natural contours, massive earthworks, tunnels and aqueducts. Apart from being expensive to build and operate, a canal with locks needs a reliable water supply since so much is wasted by the operation of a lock.
4:13, There's a slight inaccuracy. Tractive force, in fact, will not remain the same. Tractive force depends on friction, which is directly proportional to the gravitational force applied _perpendicular_ to the surface. While the overall force of gravity will remain the same, when the train climbs an incline, the component of gravity perpendicular to the surface will reduce. For a gradient of theta degrees, the force will now be the cosine theta of what it was previously.
@@kelly2631 In this case, the decrease in normal force will not be a factor in this. In fact, the normal force is proportional to the cosine of the angle of the incline. This means for an extreme angle of 5 degrees, the normal force would only decrease by 0.38%
Driver: Come on, Gordon, you're not even trying!" Gordon: "Hmph, I can't do it. Trucks are troublesome, and hold an engine back. Now if I were pulling __coaches__ , now *that* would be different."
Also worth mentioning, most locos are equipped with reservoirs of sand that is dispensed to the track in front of the driving wheels to improve traction on steep grades or during wet conditions. On steam locomotives this reservoir was on the top of the train in a dome shaped part, known as the “sand dome.”
@@slimmsherpa9771 the sand grains wouldn't be under heat for long enough (Or perhaps even hot enough) under the small contact points and the relatively short duration the train travels over them to turn into natural glass. Without a flux the sand would need to reach 3,200F or 1760C to melt.
@@slimmsherpa9771 definitely not. In chilly Canada even our light rail transit trains still use sand, (selected for type and grain size), for traction when braking and accelerating. So much so that periodically a vacuum truck comes to pick it up where it deposits in tunnels and switches.
+bohemianh Yes, that's exactly what I was thinking as well. en.wikipedia.org/wiki/Rack_railway I don't know whether there are interoperability issues with trains compatible with such systems on regular tracks. I'd also assume that the Swiss ones going up very steep slopes would be unsuitable for reasons that are obvious if you look at the shape of the train in the photo (i.e. the train itself is slanted to match the slope):- commons.wikimedia.org/wiki/File:VRB_H_1-2_bei_Freibergen.jpg
+bohemianh Cog railways are really unique and very interesting. Some even have a ratchet system so the train can't roll backwards down the grade if the brakes fail.
+NotATube There is also a system with a third rail and an extra set of rubber tired traction wheels called... Something. Ill go look it up. Looks like its the Fell railway system, and most of the time its just used for breaking force. en.wikipedia.org/wiki/Fell_mountain_railway_system
+bohemianh The train that used to connect Argentina and Chile through La Cordillera de los Andes was just like that, I remember seeing those gear-contacts beside the tracks
At 4:07 the claim is made that on an incline the tractive force remains the same. Actually, it does not. The greater the incline, the less tractive force because the accelerational force of gravity is no longer perpendicular to the track. As an extreme example, at an incline of 90 degrees the tractive force would become zero as the accelerational force of gravity is then moving on a vector that is parallel to the track.
You find that problem with freshly graduated college students a lot - they try to prove their ego by disproving experts on a national TV science show by talking in a deliberately complicated and elaborate manner or just restating what was already said on the program in a more difficult and "around the barn" way. They find out their diploma is worthless so they have to try and shine their ego to hide their insecurity.
A couple points of physics not mentioned in the video. A big part of the reason trains aren't good at climbing hills isn't just the traction: it's because, as big as a locomotive is, it's still only a small portion of the weight of the entire train. The vast majority of a train's weight is on the unpowered wheels of the cars, and isn't contributing to its traction at all. Compare this to you: all of your weight is on your feet. All of a 4WD car's weight is on its driven wheels: for a 2WD car this may be more like half of the weight. You may think you're good at climbing hills, but good luck trying to climb an 80% grade while dragging a wagon loaded with half a ton of bricks. And while your car might climb hills nicely on its own, a semi truck or lorry with four fully-loaded trailers (aka a "road train") certainly won't, despite the high grip of the tires. Conversely, a locomotive all by itself probably wouldn't have much trouble with a 2.65% grade.
Edit: I was answering to someone who deleted his comment. It would have the same traction because the only weight contributing to the traction of a train is the weight of the locomotive (where the powered wheels are). Traction is very much the same in a locomotive that drags a hundred 50 ton wagons or in that same locomotive with no load. Thats the whole point of Omnigeeks comment. I will add that, contrary to what James says, steel on steel friction coefficient is actually almost as high as that of a car tire on a road
Jeff T I dont think you get the point. Only two variables affect friction force: friction coefficient, and weight (more accurately, normal force). If the force delivered in order to push the train (the traction force) exceeds the friction force, you slip. The higher the friction, the higher the traction (and the locomotive power) can be. Friction coefficient is actually not that low steel on steel, so thats not the main problem. Problem is, the only normal force that affects friction is that on the powered wheels, that is, the weight of the locomotive. The number of wheels on the locomotive does not have and effect on that at all, assuming all are powered. So, the train has to pull all the wagons only with the traction that itself can create, with its own weight. Not usually a problem in a flat surface, but in a slope normal force sharply decreases and thus traction and maximun power output too. Thats why locomotives need to be heavy. In addition, the added weight force derived from the slope is hard to overcome. So, it all comes down to traction, but the reason traction is low is not only that steel on steel is slippery, but that all of that traction is limited by the locomotives own weight, instead of using the whole trains weight.
Jeff T no amount of traction will make a freight train go uphill, it’s all in the power of the locomotive. Giving the train more traction wont do a damn thing
+Clyde Wary Yes, mistake #1. Mistake #2: stairs are about 80%, not 80 degrees. Mistake #3: the illustration at that point shows a (roughly) 80-degree slope and labels it 80%. We probably should've stopped watching at that point.
+Paul Kennedy I had the same thought and paused the video to look for correcting comments. But nevertheless I watched it full length just becuase of James' really nice shirt!
+Clyde Wary If you listen carefully, when he says 80 degrees, a text pops up saying that 80 degrees is about 567%, which is correct. The 80% illustration and the commentary are not related.
@@weeziteer actually I was just trying to make a point. You can spell it either way. Americans tend to go for your spelling while the rest of the English speaking world tend to go for 'realised'. So correcting someone's spelling of the word isn't really necessary.
@@weeziteer its realised unless your an american in which your language is wrong anyway, oh what should we call this season that leaves fall of trees... Ahhhh fall ( facepalm)
The “tractive” force actually slightly decreases as the train travels up a gradient, it doesn’t remain constant as the video suggested this is because now a component of the trains weight is acting horizontally and thus not proving a downward force into the tracks. It’s only a small fraction however due to the fact the slopes the trains travel up are extremely shallow.
It's James May, so what do you expect. He also suggested that stairs are 80% grade. Just be thankful that the bigoted big mouth Jeremy Clarkson isn't with him.
Another problem on steep inclines, is keeping the water level constant, especially going downhill. The crown in the firebox needs to be covered at all times. On some downhill runs, the loco has to go in reverse.
As a swiss train driver, I applaud to your video, and might show it sometimes to people who think that, well, driving a train is probably as easy as being in a car that doesn't need steering, ey? Actually, the biggest economical advantage of the train which is its small friction is also the greatest nightmare for the railway operators. One day, I was driving downwards well below the maximum authorized speed due to bad weather and rail conditions (leaves in autumn). Suddenly, my personal feeling made me think that the train seemed a bit fast, especially in the turnings. So I reduced the effort of the electrical brake and suddenly the speed indicator goes 20 km/h up! Due to the slippery tracks and braking effort, the wheels were actually turning slower than the real speed of the train would have make them do, thus influencing the speed indicator!
@@phoenixarian8513 Yes that would be one possibility, but for example for the european Train Control System (ETCS) which needs positioning, they decided against it to not be dependent on satellites and their operators (mainly the Americans back then when the system was developped). Some modern trains have a single axle that does only brake in emergency situations but not during standard braking. This way it always turns with the real speed, and it is on it that the velocity is measured. However, this wasn't the case on my older regional train and is still not the case on locomotives for freight trains for example ;-)
@@Maciliachris I am Chinese and they have their own satellite system, so that isn't a problem. (And yes, China does not trust American satellite service either) One axle left unbraked doesn't matter actually, as westinghouse system brakes ALL axles including those on cars. Engine braking is nothing compared to this. As with the positioning systems I heard that HSRs had got these already. Not ordinary engines.
As a locomotive Engineer with 25 years experience, I can attest to all of Jame May's talking points. I have run on grades of 3.0 percent and you have to be on your "A Game" for that kind of work. The real issue arises when fuel conservation trumps tractive effort. Fun times.
@@okamijubei Well the Snowdon Mountain Railway uses a system kinda like a rollercoaster! Though instead of having the chain move the train the train uses static teeth to climb.
This is a very helpful video for those of you who wonder why Gordon keeps getting stuck on his hill. Now, I know some of you would chalk this up as Gordon being lazy. But even times where Gordon actually tries, he still gets stuck. Now, this can depend on how many passengers ride the Express, the number of coaches Gordon pulls on a daily basis and how quickly he travels with the Express. Considering that the Express coaches are based on the BR MK1 passenger coach, a single one of these coaches can seat 48 passengers. And in the series Gordon is typically seen pulling 5 coaches and one brake coach. So with a packed Express, Gordon would be carrying 240 passengers and their luggage, along with the Guard in the brake coach. A single BR coach weighs 27 long tons, or 60,480 lbs in US terms. And considering that there is a total of six coaches in total on the Express, Gordon would have to be pulling a total of 362,880 lbs or 162 long tons. So yeah, it's no surprise Gordon keeps getting stuck on his hill. He'd have to be moving at a fairly decent speed to make it over his own hill. Take Gordon's his brother, the Flying Scotsman, for example. Scotsman can easily reach 100 mph, and considering that Gordon is an A1 Pacific, it's possible that he is capable of reaching the same speeds. However, the Express does have a speed limit as to how fast it can go. So in order to make it over the hill, without a back engine, like Edward, he'd have to maintain a constant rate of speed without stopping, in order to avoid getting stuck. I'd say something around 60 mph, 75 at most. (Hopefully this provides some insight.)
On 2.65% it's 2.65% the gravity of the whole train turns to drag and for a 250 ton train (the loco itself weights 92 tons) it's 66.25 KN of drag. A1 can do 132KN so he should be still able to pull it off although it would be really slow and probably need sand. However if the train is heavier than this it might not be that lucky for Gordon. Imagine 5 Chinese passenger seaters packed with 200 passengers inside each of them?? (Search for Spring Festival Rush if you can't imagine) It would be 66 tons each. Yikes.
The breaks have a much larger advantage over the acceleration when it comes to trains as only a few of the many wheels apply power to accelerate, but all the wheels can apply breaking force.
Small mistake in the video: at 4:07 he says the "tractive force remains the same" on the incline. This is not true. It actually becomes less (making it more challenging for trains to climb hills. In physics terms the force of friction is equal to coefficient of friction (steel on steel) multiplied by the Normal (support force). This Normal force become less on an incline.
Here in the Appalachians we have a few lines with over 10%, and freight gradients are also 3-5% generally. It just proves the technological marvels that are modern trains.
They probably don't have too heavy of a load compared to the USA or Mexico freight trains that have 120 to 180 wagons and at least half are double stacked. The greater the load, the more torque is required, and to transmit that torque you need more friction.
one litle comment: The weight pressing on the tracks is reduced when going uphill/downhill (you can split the weight into the component parallel to the tracks and the one orthogonal to it. When perfect leveled the orthogonal one is 100% but when going up a 30 degree angle it is only 50%
+Christian Kunert Thinking about it in my head wouldn't the force becoming down over an area aft of the contact patch of the wheels on an incline where on level ground its coming down overtop of it?
For those of you who are confused as to how a locomotive will gain traction in the first place (since like he said steel on steel has little friction), locomtives will use sand to gain a grip on the rails, and as it gains speed, sand is no longer needed. Sand is also used on a locotive's wheels when tackling an incline.
@@jonathanoxlade4252 is the chain lift you are talking about what roller coasters use during that initial steep incline of the ride? (i look back at this question and i think to myself..."duh, moron..." but nevertheless, i'll just make sure i understand- and, yeah, why don't they do the chain lift?)
Better solution there is cog railway. There are even some that engage the cog only where needed. But as for why not: it’s super slow, high maintenance, not particularly efficient or high capacity and did I say super slow? It’s really only an option for passenger railways that are intentionally climbing a mountain. If you’re just passing through a mountain range with freight, the tunnels etc are more efficient.
I knew this already from playing Railroad Tycoon in the 90's. I even knew what the max. gradient would be. It's one of the most important factors when laying track. Funny how that "game" taught me about railroad engineering as well as the stock market, etc.
@@TrainsfanAlex6060 how would that not help for hills? Sanding is a method to gain traction, it doesn't discriminate whether you're on a hill or not...
@@ThePedro8161 The amount of sand is limited. Trains plan to climb hills without sand and only use it when rail conditions are bad or some bleeeeerp railway guy sets signals in a way that forces a Pacific (not the best hillclimber) to stop on a Hill (they used a BR52 as a pusher in the end)
A few years ago I was going down a 14% grade in the Rocky Mountains and saw a freight train coming up the same grade on the tracks next to the road. If you get out in that part of the world (and I presume in the Alps), you will see lots of trains going up some pretty steep grades.
I used to live in Chamonix Mont Blanc (French Alps) and the main line going through the valley has to climb up a 1 in 11 gradient on part of its route. That's all friction based, using light weight trains, wikipedia "Saint-Gervais-Vallorcine railway" if you're interested. There are much steeper trains in/around the valley but they use rack and pinion.
I honestly think James has all of this knowledge in his head already. I wonder how much research he truly has to do to produce a show like this. Say what you want about his choice of shirt or his lack of forward speed, but this man is a true joy to watch. Especially when it is something he is passionate about.
The best locomotives for tackling grades are American geared steam locomotives (the Shay, the Heisler and the Climax locomotives). I have heard of a Shay going up a 14% grade before. That's why they were so popular with logging railways. If you haven't heard of aforementioned locomotives, I then suggest you look them up. They're really quite amazing!
James May, you completely forgot that us Americans have locomotives that can go uphill (very slowly) with great ease! The Shay, Climax, and Heisler locomotives can conquer grades of up to 9% by way of geared wheels. Some even have two gear transmissions. Even though they're very slow, they still get the job done, especially in logging country, as opposed to rod driven locomotives. The Lickey Incline has had it's fair share, but it's nothing compared to grades like Freighthouse Hill in Tacoma Washington for example (3.5% Grade, and took a rod engine and an GM-EMD F9A to tackle it with a four car excursion train two-and-a-half years ago; that's fire and thunder there!). Good explanation though sir, and now if you'd be so kind to explain why we have no "Flying Boats" of substantial size anymore, or why we are attracted to gaudy cruise ships, over proper ships like ocean liners? Then I'd most definitely be thrilled. Cheers sir, cheers. Complements to your airship video too.
For that matter, he mentions the Eurostar, which partially runs on the french high speed network. Both TGV's and 3rd generation german ICE trains run on routes with a 4% gradient without any special adaptations at all... And special purpose geared locomotives can go up steeper slopes than cars can handle...
Steven Michael Well, maybe... Freight trains are in general longer than passenger trains, but even if they are not, they are often heavier regardless. But, the thing all these high speed trains tend to have in common, is well, high speeds. Many of the steepest gradients on high speed routes are momentum gradients, which trains can only actually climb consistently if they're going fast enough to get to the top through momentum alone. The German ICE routes also show the impact of distributed traction. The Cologne-Frankfurt route has 4% gradients. ICE 3 trains can run over it with ease, but ICE 1 & 2 trains are not allowed on the route. Even though they could make it over 4% gradients when at speed, they are not allowed on the route because if they come to a complete stop for some reason, they would at best manage a 3.5% gradient. The ICE 3 has a higher power to weight ratio than the older two versions, but it also distributes that power over the entire length of the train, with every other car being powered, and 50% powered axles overall, compared to just 8 out of 56 axles (~14%) in an ICE 1 being powered, or 4 out of 32 (12.5%) in an ICE 2 set...
Yes, short line railroads especially have to take runs at hills. Inertia = Efficiency. I'm not sure where you live, but in America, most passenger trains have about 10 cars while freight often have over 100. Also, passenger trains use locomotives that are made for acceleration rather than power. Lastly, as you said high speed trains run fast (no kidding!) and bigger speeds mean less traction. Best Regards
Another solution is to spread traction power accross the train. At the German ICE 3 for instance, it can maintain 300 km/h (185 mph) at a gradient up to 4% because of the traction power being divided along the train (it also allows quicker acceleration)
Yes MU rushes through grades with ease because he has the full train as weight. For conventional setup if the train is too heavy and the loco is too lightweight it won't move even if the loco has a superman in it. It's the problem of traction like pushing a heavy box on ice. Your feet will slip and the box will never move. However MUs are expensive to use therefore it's only good for HSRs. Freighters have little profit in each haul and using MU as freighters would eat all your profits. Sad truth. Freighters can't afford MUs and had to use conventional setup.
@@SpeedBird6780 I've heard europeans have so little freight loads that the semitrucks are gonna do this job instead. If there's only a handful of them to deliver some high value cargos such as automobiles this will still be affordable. Just thinking about delivering some heavy items such as COAL or IRON ORE with MU makes the treasurer scream.
@@phoenixarian8513 I was talking passenger services, freight services still all have locomotives run it (obviously). It wouldn't be feasible, even in Europe, to run MU set-ups on freight trains as usually, there are cars with multiple destinations on one train and that needs to be exchange. I thought I was pretty clear that I was talking passenger services in my previous comment.
I always thought it was unfair that the 'Leaves on the line', and 'The wrong kind of snow' explanations for delayed trains in Britain were mocked by the media. The new snow-clearing machines (imported at great cost, no doubt) were designed for shifting overseas-type snow - the kind of light to medium powder that forms 12' deep drifts in places like Finland and Canada. The lovely, new-fangled snow-blower/scrubber/whatever devices worked brilliantly on that stuff. BUT... In Britain the snow may only be 6" deep, but it's almost never powdery. No, no, no. It's 5" of dense grey sludge with an inch of beautiful crystal clear ice on top of it. Yummy! Trains don't like it. Snow-clearing devices don't like it, even the massive Russian flamethrower-type ones. Ye olde steam locomotives could be modified to chisel it up as they went, but modern units are set up differently and crud on the line is a real problem. So much for progress. Wet leaves on the line are another ridiculous-sounding but genuine disaster because they squish down into a kind of greasy plywood that reduces traction to zero. British 'wrong snow' is a pain to shift. Bear in mind that 'winter' here lasts for 5 hours on a Monday, then reappears two days later for 16 hours, before bright sunshine takes over until teatime, followed by winter 2, where snow falls, freezes, melts by lunchtime, refreezes by teatime, clears completely after a day of blazing hot winter sun/fog/sleet/hail/rain, then gets topped up by snow in time for lunch the next day, which turns to 3" of ice overnight... etc. In Canada you can plan for winter. Properly. It lasts for blooming months. Snow tyres or chains on the car; full-time track-clearing machines for the railways... In Britain it comes and goes totally unpredictably. Can't use snow tyres or chains on the car because the roads change from ugh to aargh overnight. Sometimes winter's quite warm and sunny. For three hours. Everything melts. Yay! Just before a five day ice-storm which brings down all the power lines. Boo. But which then melts overnight. Sometimes. So investing millions of quid in fancy, Arctic-spec snow-clearing gear for the railways is one hell of a gamble. Yes, I know it sounds like a stupid cop-out, but them's the facts. The way you shift so-called snow hereabouts involves 6 guys with pickaxes, shovels, and huge mugs of hot, sweet, milky tea, walking ahead of the train as if it were still 1885. So when the rail official (perhaps foolishly) told the journalist that the trains weren't running because the wrong kind of snow was on the line, he was being absolutely honest, which is never a good idea when dealing with the British media.
So a train can be halted by a simple pile of leaves? I will harness the power of nature and its leafy friends just to screw over the passagers. *evil laugh* But seriously though,trains and slippery surfaces don't mix.
Also, in the rare occasion that the UK gets fine powder snow, it gets sucked into the traction motor cooling system and melts right in the heart of the electric motors. Shorting them out.
All of this is true but I am still unimpressed that the country that invented the railways and was the cradle of the industrial world, famed for its industry and ingenuity could not scrape a few wet leaves and a bit of snow off a railway line.
@@Chadmiral Wet leaves can give trains flatties as well. Really they are flat spots rather than flat tyres but it's just like in F1 if a driver skids too much when braking the friction flattens the wheel causing vibrations. The wheels need to be reground when this happens. In F1 at least you can just change the tyre.
The Rimutaka Incline on Wellington New Zealand operated by steam locomotives for 80 odd years on a line with a gradient of 1 in 15. It's amazing how little the engineering enthusiasts of the world know about the little railway. It used a centre raised rail with horizontal cog-like grip wheels to help the locomotives climb the hill on the return journey. The same centre rails were used for supplemental grip on the descent. Look it up!
Here's a video of them in action. There is a full feature length one lurking around somewhere bit I think it keeps getting taken down. ruclips.net/video/DSCDfXiDNI0/видео.html
Just a small point. When trains came about in the 1800's, many engineers tried to come up with alternative systems, like rack and pinion, that would increase traction on rails because of the idea that a train on a rail would meet and an extremely small, and theoretically infinitely small point, since the intersection of a circle with a line is such. This continued until a scientist was able to show that this is not in fact what happens at all. If you take a steel ball and bounce it off concrete, you will see what happens. It bounces. Rubber bounces because it flexes and returns the energy to the ball to bounce it. Steel flexes as well, but it is so resistant to flexing that it flexes much less, but it takes much more force to do that. However, the force imparted to the steel ball is returned to bounce the ball again, in proportion to the force imparted. This is why that steel "clack clack" toy works. When a rail car meets the steel rail, it actually flattens under the force of the weight of the rail car. It is not much. The contact point is about that of a dime. However, even that point of contact, under the tremendous force of the weight of the car acting on such a small point of contact is enough to flatten the steel and actually make for a pretty good, if temporary, contact with the rails.
@@ThePedro8161 - Until you want to slow or stop the train. Then every wheel has brakes, so trains can stop in a much shorter distance than they can accelerate. On passenger trains that have electrically controlled brakes the emergency stopping distance is much shorter than freight trains that have train line (the pipe that supplies compressed air to the brake system on each car) controlled brakes.
There is a town in Utah, USA called Helper. This is because the steep climb trains would have to make in the area necessitated “helper” engines to do so.
I was expecting Clarkson to come in the comment section and type "this is the most boring thing on earth after May driving on the track" or something like that
Reading visual novel about old steam trains, and this information actualy helps me understand the material even more. Thanks. Old steam locomotives are just great beings.
I think the people that wrote the story knew what they were talking about.The Little Blue Engine is a switcher engine, which has more power and traction than your typical locomotive. That was why it was the only engine that could get over the hill. The unrealistic part of the story is the idea that anyone would be dumb enough to run a train track straight over a hill.
While it is abandoned for now, the steepest standard gauge mainline climb in the U.S. is Saluda Grade, originally owned by the Southern and eventually Norfolk Southern until it was abandoned in 2002 I think. With the worst of it being 4.9% for a hundred yards and the average reaching 4.3%, the gradient was often a railfan favorite. Don't worry about it being turned into a railroad trail (a walking path that travels along ripped up lines), I hear NS has sold the property to a short line railroad who wishes to bring the gradient back to life.
Nice presentation. Trains can go up hill. 1. The Stoosbahn is a FUNICULAR railway with a maximum gradient of 110% and is the steepest funicular railway in Switzerland and in Europe. 2. Katoomba Scenic World is a steepest CABLE railway in the world with a gradient of 128%. 3. COG trains. The Pilatus Railway is a mountain railway in Switzerland and is the steepest rack railway in the world, with a maximum gradient of 48% and an average gradient of 35%. The first mountain cog railway was the Mount Washington Cog Railway in the U.S. state of New Hampshire. 4. Lisbon Tramway has gradient of 13.8% in Lisbon, Portugal. 5. Pöstlingbergbahn in Linz, Austria has a maximum grade of 11.6% and is one of the steepest adhesion railways in the world. Because you did not talk about Funiculars, Cable trains, trams or Cog trains or about trains with extra adhesion. Last is a train with no rack system. 6. Montreux-Oberland Bernois railway (abbreviated MOB) in Switzerland has a gradient 7.3% Trains can beat this railway. Funny thing. Taken to its logical conclusion as the slope becomes vertical, a funicular becomes an elevator.
Yea but you took the bait thats why its a trick question. He means reg trains like the UK/EU uses Steam engines still and the USA uses mostly diesel-electric and sumtimes they use steam. We all know cable cars and COG trains that were specially built to go up steep incline.
Funiculars have geared wheels and rails and are not considered regular rail. The maximum incline for ordinary trains is 30 permils while metro EMUs can up to 35.
He is clearly talking about standard passenger and freight trains that run on starndard smooth rails, not rack and pinion trains that are specifically designed for going up gradients standard locomotives can't.
no, not at all! friction limits trains: if angle_tohorizontal axis > arctan(friction_coefficient) then they would have no grip anymore. the friction coefficient at steel touching steel is ~0.1 lets assume we can achieve 0.15 with extra sand: alpha_:horizontal = arctan(µ) tan(alpha_horizontal)= hill_gradient = µ *hill gradient* = *k* = *tan (alpha)* = µ ->k= 0.15 = 15% proof: example: train climbing a hill with angle of b; the force on the wheels shall be equal to the max. traction force(->max. friction) Then as mechanical engineering tells us: *a)* Sum(forces in x)= m*a + F_r_friction - mg* sin(b)=ma special case: a=0 -> max angle: ->F_r_friction= mg sin(b) *b)* Sum(forces in y)=0: +F_normal - mgcos(b)=0 F_n=mg cos(b) 1)-> Fr_friction= µ * F_n = µ * mgcos(b) 2) Fr_friction = mg sin(b) Fr_friction=Fr_friction µ mg cos(b)= mgsin(b) µ= tan(b)! if µ>tan(b) -> train can go up steeper than angle of b. if µ train cannot climb the hill with angle of b.
I was a Locomotive Engineer for a major Railroad C.S.X. and you are right about wet rail or leaves on the rail all slippery conditions but whenever I had slipping wheels or spinning out of control wheels I would use my SANDERS .It helped most of the time NOT ALWAYS but most of the time !
+scowell came here to say just that. So the part of the weight that pulls back on the train also doesn't push down on the wheels anymore so you could say the incline is a double edged sword. Oh and another mistake: max speed is when the sum of the air drag and the wheel drag equals the traction force not just the air itself.
+scowell I'm not sure why he mentions the contact area either, when discussing traction. In most cases, it's not a significant factor, right? It's all about the normal force
0dWHOHWb0 I thought so too but apparently the surface does matter: or at least when rubber and asphalt are in use: wider tires, better traction. But I think that's because the rubber kinda adheres to the surface and so you cannot apply the F=u*N formula. So idk how that works in trains but still..
When I was training to be a conductor in Seattle, I took a coal train over the mountain, to the east. We had just gotten to the top of the mountain, and found ourselves at an absolute signal that was red. The engineer was stopping the train, but it was still rolling about 2 MPH. It was snowy, and icy. I was shitting my pants. It finally came to a stop before we reached the signal.
Last year, I was the conductor on a train (lite power). We were going 60MPH and came up to an absolute signal that protected a diamond was all red around a corner. I freaked out and dumped the train (2 engines) and we went from 60MPH to stopped within 500 feet.
Wont work, not nearly enough thrust. Fully loaded Trains can weigh as much as FIVE Navy Destroyers. So, we have the weight of three warships on roller bearings. The rocket wont do crap.
True. I saw a photo of a section of damaged track in the US where a coal train had come to a halt, but the Distributed Power locomotive either in the middle or on the rear of the train had not received the command to stop and the wheels had ground themselves into the track. There were twelve wheel ruts in the track at two distinct locations corresponding to the two bogies. It was a real mess and that loco would have been pretty stuffed too. I suspect that the train engineer may have lost his job over that one.
@@anfasharchive3244 Pacifics. They Run away from any incline (but FAST). Hills are for 1Eh2' or 1Eh3' engines (2-10-0) like the 40 and 50 series Einheits-Dampflokomotiven
Two important factors at least with North American freight hauling locomotives is distributed power and the ability to motor them independently and the fact that very few freight trains attack the grades seen in the places like the Rockies with out a full compliment of sand in their hoppers.
There are 2 types of brakes on modern locomotives, the air brakes and the dynamic brakes. Dynamic brakes in simple turn the traction motors into generators. So the locomotives do most the work air brakes are only used if the train starts going to fast.
I wish he would have mentioned that trains squirt sand on the rail in front of the wheels for traction. Also, a runaway train can cause the track/wheels to have a thin layer of molten steel which makes it go even faster
That's why locomotives have what's called a "sander," to literally drop sand on the rails and create friction. This comes in handy when both climbing hills, and when running during the rainy season. In the earlier days of steam, they would just throw the sand out in front as they ran along, like what the fireman had to do in "Edward's Exploit," for you Thomas fans out there. This is not without problems of its own, however: in sufficiently wet weather, the wheelslip can turn the wet sand into mud, making the situation even worse than before, as seen in "Leaves." An episode which, coincidentally, revolved around a more hot-headed and less intellectual James.
trains go uphill, we have train tracks from Beirut to bekaa, they pass by a 1700 meter altitude passage. Beirut is at sea level, and the length of the trip is about 30 km
*BUT THEY DID IN POLAR EXPRESS*
STFU that dude tokyo drifted a train on ice
I WAS THINKING THE SAME THING
its a magic train..........
Richard the Wolf Schleich lol 😂
It’s a powerful train
Hill: *exists*
Thomas had never seen such bullsh*t before
Muzzammil Ahmer look out of the train!
lol
*laughs in Gordon’s hill*
@@thelunaticcultist5157 Bruh!!! Isn't that a reference from the Classic series? 😂
@ Indeed. You can actually here one of the crew saying it during an episode.
Canal boats are even worse at climbing hills.
hence locks
@@Sugarsail1 Yes, when all else failed. Often though, the solution was circuitous routes that follow the natural contours, massive earthworks, tunnels and aqueducts. Apart from being expensive to build and operate, a canal with locks needs a reliable water supply since so much is wasted by the operation of a lock.
id say
Haha good one
Yes.Up a water falls or rapids
4:13, There's a slight inaccuracy. Tractive force, in fact, will not remain the same. Tractive force depends on friction, which is directly proportional to the gravitational force applied _perpendicular_ to the surface. While the overall force of gravity will remain the same, when the train climbs an incline, the component of gravity perpendicular to the surface will reduce. For a gradient of theta degrees, the force will now be the cosine theta of what it was previously.
good ole normal force
I really don't think that most people would understand the concept of normal force tbh, but yeah, it's proportional to the angle of the incline.
@@kelly2631 In this case, the decrease in normal force will not be a factor in this. In fact, the normal force is proportional to the cosine of the angle of the incline. This means for an extreme angle of 5 degrees, the normal force would only decrease by 0.38%
Ah . Pedantry abides here . But you're dead right .
Okay copy and paster.
*has a huge midterm tomorrow* decides to watch why trains can't go uphill
How'd it go man?
he went downhill
and I am currently earning for exams next week....damn university :D
Lol same
Priority’s on point
Suddenly Gordon not getting up Gordon’s Hill makes more sense
GN or a banker engine to help them up it
@@whitewolf8051 F for Edward
@@TCTheDS F
Driver: Come on, Gordon, you're not even trying!"
Gordon: "Hmph, I can't do it. Trucks are troublesome, and hold an engine back. Now if I were pulling __coaches__ , now *that* would be different."
@@TCTheDS F
This guy has clearly never heard of the immense power of The Little Engine That Could.
Ork willpower is strong
Unlikely. I think he has I think he has I THINK he has I-
It should be illegal to call James may "this guy"
He never said the engine couldn't, just that there's a reason the story isn't about the little wheel that could
Thank you
Also worth mentioning, most locos are equipped with reservoirs of sand that is dispensed to the track in front of the driving wheels to improve traction on steep grades or during wet conditions. On steam locomotives this reservoir was on the top of the train in a dome shaped part, known as the “sand dome.”
I’m sorry it’s 8 months later but do you know if it turns into glass?
@@slimmsherpa9771 the sand grains wouldn't be under heat for long enough (Or perhaps even hot enough) under the small contact points and the relatively short duration the train travels over them to turn into natural glass. Without a flux the sand would need to reach 3,200F or 1760C to melt.
@@slimmsherpa9771 definitely not. In chilly Canada even our light rail transit trains still use sand, (selected for type and grain size), for traction when braking and accelerating. So much so that periodically a vacuum truck comes to pick it up where it deposits in tunnels and switches.
Damn, that would’ve been cool. Makes sense, they definitely would have thought about that before using sand. Thanks gentlemen.
@@francistarkenton545 funny, one is not suposed to sand into switches
I could listen to James May talk about literally anything for hours and it would be interesting.
TheBounceMaster The Morgan Freeman of Britain.
CPD0123a iindeed :)
TheBounceMaster I can imagine him going Bla Bla Bla every two sentences and nobody would even notice.
TheBounceMaster tell that to Jeremy Clarkson
TheBounceMaster Nothing better than good common knowledge. James does an excellent jpb explaining it.
In Swiss and German Alps there are trains with gear wheels that lock into the gear teeth on the rails. The Train can climb extreme rises.
+bohemianh Yes, that's exactly what I was thinking as well.
en.wikipedia.org/wiki/Rack_railway
I don't know whether there are interoperability issues with trains compatible with such systems on regular tracks. I'd also assume that the Swiss ones going up very steep slopes would be unsuitable for reasons that are obvious if you look at the shape of the train in the photo (i.e. the train itself is slanted to match the slope):-
commons.wikimedia.org/wiki/File:VRB_H_1-2_bei_Freibergen.jpg
+bohemianh Cog railways are really unique and very interesting.
Some even have a ratchet system so the train can't roll backwards down the grade if the brakes fail.
+NotATube There is also a system with a third rail and an extra set of rubber tired traction wheels called... Something. Ill go look it up.
Looks like its the Fell railway system, and most of the time its just used for breaking force.
en.wikipedia.org/wiki/Fell_mountain_railway_system
Culdee Fell Railway
+bohemianh The train that used to connect Argentina and Chile through La Cordillera de los Andes was just like that, I remember seeing those gear-contacts beside the tracks
At 4:07 the claim is made that on an incline the tractive force remains the same. Actually, it does not. The greater the incline, the less tractive force because the accelerational force of gravity is no longer perpendicular to the track. As an extreme example, at an incline of 90 degrees the tractive force would become zero as the accelerational force of gravity is then moving on a vector that is parallel to the track.
Shut up nerd
Ok fair point, still proves the point he was trying to make which means it near enough makes no difference anyway.
You find that problem with freshly graduated college students a lot - they try to prove their ego by disproving experts on a national TV science show by talking in a deliberately complicated and elaborate manner or just restating what was already said on the program in a more difficult and "around the barn" way. They find out their diploma is worthless so they have to try and shine their ego to hide their insecurity.
@@edvardstepanyan1164 shut up dumbass
@@craigthelej go play fortnite virgin
They managed to do a Q&A with James May and keep it at under an hour? Impressive
But what if the train is made out of an Audi S8 and a few caravans?
I see what did there.... TOP GEAR
Hahaha ask Jeremy about that 😂😂
CWINDOWSsystem32 chased by a tgv
Then call world's strongerst man
Jeremy will come to win the race
There's something about a British guy talking about trains that makes me feel really nostalgic.
"miss your dinner" this also
Thomas
I disagree. This sounds more like a peasant, British, dialect. It is annoying and incorrect.
Bogusgal please don’t be that guy
They colonised the Globe with their trains!
Thomas the tank engine struggled up a hill once. I remember that.
you made me laugh
Thomas the Wank Engine.
Ahhahah..me too👊
look out for the train!
I think it was because the fat controller was hitching a ride
"trains can't go up hills"
Funicular, Incline, Cog, and cable cars:
*Am I a joke to you ?*
And the train known as ”big boy”
Ever hear of Saluda Grade and the Madison incline they ran coal drags through those Grades daily in the 1930's
Just goes to show how stupid people are these days
Nick Goetsch your the one who spelled heard right
@@railfano172 Thanks for that but in Wisconsin that's how a lot of people talk
A couple points of physics not mentioned in the video.
A big part of the reason trains aren't good at climbing hills isn't just the traction: it's because, as big as a locomotive is, it's still only a small portion of the weight of the entire train. The vast majority of a train's weight is on the unpowered wheels of the cars, and isn't contributing to its traction at all. Compare this to you: all of your weight is on your feet. All of a 4WD car's weight is on its driven wheels: for a 2WD car this may be more like half of the weight.
You may think you're good at climbing hills, but good luck trying to climb an 80% grade while dragging a wagon loaded with half a ton of bricks. And while your car might climb hills nicely on its own, a semi truck or lorry with four fully-loaded trailers (aka a "road train") certainly won't, despite the high grip of the tires.
Conversely, a locomotive all by itself probably wouldn't have much trouble with a 2.65% grade.
Omnigeek6 Good point well made.
Edit: I was answering to someone who deleted his comment.
It would have the same traction because the only weight contributing to the traction of a train is the weight of the locomotive (where the powered wheels are). Traction is very much the same in a locomotive that drags a hundred 50 ton wagons or in that same locomotive with no load. Thats the whole point of Omnigeeks comment.
I will add that, contrary to what James says, steel on steel friction coefficient is actually almost as high as that of a car tire on a road
My god finally someone in the comments gets it right.
Jeff T I dont think you get the point. Only two variables affect friction force: friction coefficient, and weight (more accurately, normal force). If the force delivered in order to push the train (the traction force) exceeds the friction force, you slip. The higher the friction, the higher the traction (and the locomotive power) can be. Friction coefficient is actually not that low steel on steel, so thats not the main problem. Problem is, the only normal force that affects friction is that on the powered wheels, that is, the weight of the locomotive. The number of wheels on the locomotive does not have and effect on that at all, assuming all are powered. So, the train has to pull all the wagons only with the traction that itself can create, with its own weight. Not usually a problem in a flat surface, but in a slope normal force sharply decreases and thus traction and maximun power output too. Thats why locomotives need to be heavy. In addition, the added weight force derived from the slope is hard to overcome.
So, it all comes down to traction, but the reason traction is low is not only that steel on steel is slippery, but that all of that traction is limited by the locomotives own weight, instead of using the whole trains weight.
Jeff T no amount of traction will make a freight train go uphill, it’s all in the power of the locomotive. Giving the train more traction wont do a damn thing
James May please never go away
noobenstein ...
noobenstein he could but it'd take him forever to "go away" get it because he's slow
he will go away and he will lost his way
Ha aha that rhymes
unlike theresa may
"80 degrees" is NOT "80 %." An 80 % grade is one that rises 80 ft for each 100 ft travelled horizontally. An 80 % grade is about 39 degrees.
+Clyde Wary Yes, mistake #1. Mistake #2: stairs are about 80%, not 80 degrees. Mistake #3: the illustration at that point shows a (roughly) 80-degree slope and labels it 80%. We probably should've stopped watching at that point.
+Paul Kennedy I had the same thought and paused the video to look for correcting comments. But nevertheless I watched it full length just becuase of James' really nice shirt!
Same though, I'm sure James May doesn't think that a set of stairs is only 10degrees less steep than a wall
+MIND MILK thought
+Clyde Wary If you listen carefully, when he says 80 degrees, a text pops up saying that 80 degrees is about 567%, which is correct.
The 80% illustration and the commentary are not related.
Hills: *exist
Gordon from Thomas: *sweats nervously
Who just realised trains can’t go uphill?
Now when i think of it, thats why they make holes in mountains to go through...
Trydodis *realized
@@weeziteer realised *
Steven Mackenzie You made the same grammatical mistake as him, it’s “realized”
@@weeziteer actually I was just trying to make a point. You can spell it either way. Americans tend to go for your spelling while the rest of the English speaking world tend to go for 'realised'. So correcting someone's spelling of the word isn't really necessary.
@@weeziteer its realised unless your an american in which your language is wrong anyway, oh what should we call this season that leaves fall of trees... Ahhhh fall ( facepalm)
1:39 James trying to read the script
Wouldn't make sense cuz he's not wearing bifocals
The “tractive” force actually slightly decreases as the train travels up a gradient, it doesn’t remain constant as the video suggested this is because now a component of the trains weight is acting horizontally and thus not proving a downward force into the tracks. It’s only a small fraction however due to the fact the slopes the trains travel up are extremely shallow.
Wouldn't it remain the same if the slope is constant? The horizontal force vector wouldn't be changing, would it?
The "tractive" force would be 99.96% on a 2.65 % slope compared to an even surface.
@@kj_H65f It remains the same for all points along the (constant) gradient, but it is slightly less than on a horizontal track, yeah.
It's James May, so what do you expect. He also suggested that stairs are 80% grade. Just be thankful that the bigoted big mouth Jeremy Clarkson isn't with him.
@@24pavlo yeah, technically not the same, but practically speaking, the same
Another problem on steep inclines, is keeping the water level constant, especially going downhill. The crown in the firebox needs to be covered at all times. On some downhill runs, the loco has to go in reverse.
Going reverse would severely damage the tracks. But you are very right. If you melted your boiler then it's SHTF.
As a swiss train driver, I applaud to your video, and might show it sometimes to people who think that, well, driving a train is probably as easy as being in a car that doesn't need steering, ey?
Actually, the biggest economical advantage of the train which is its small friction is also the greatest nightmare for the railway operators.
One day, I was driving downwards well below the maximum authorized speed due to bad weather and rail conditions (leaves in autumn). Suddenly, my personal feeling made me think that the train seemed a bit fast, especially in the turnings. So I reduced the effort of the electrical brake and suddenly the speed indicator goes 20 km/h up! Due to the slippery tracks and braking effort, the wheels were actually turning slower than the real speed of the train would have make them do, thus influencing the speed indicator!
Damn. Seems like an additional satellite positioning system is needed to identify such a case.
@@phoenixarian8513 Yes that would be one possibility, but for example for the european Train Control System (ETCS) which needs positioning, they decided against it to not be dependent on satellites and their operators (mainly the Americans back then when the system was developped).
Some modern trains have a single axle that does only brake in emergency situations but not during standard braking. This way it always turns with the real speed, and it is on it that the velocity is measured. However, this wasn't the case on my older regional train and is still not the case on locomotives for freight trains for example ;-)
@@Maciliachris I am Chinese and they have their own satellite system, so that isn't a problem. (And yes, China does not trust American satellite service either)
One axle left unbraked doesn't matter actually, as westinghouse system brakes ALL axles including those on cars. Engine braking is nothing compared to this.
As with the positioning systems I heard that HSRs had got these already. Not ordinary engines.
Why does anyone listen to anyone British?
Wouldn't the wheel slip detector have been going off?
1:39 That strange face James makes while waiting for his cue.
As a locomotive Engineer with 25 years experience, I can attest to all of Jame May's talking points. I have run on grades of 3.0 percent and you have to be on your "A Game" for that kind of work. The real issue arises when fuel conservation trumps tractive effort. Fun times.
GE or EMD?
@@chariotgroupjohn Both, in all configurations.
Are James and you just saying the rails are slippery?
Sonny, u now have two point eight decades experience in railway engineering as of 2022.
@@russtorque2993 shut up
If a train has trouble going up a hill, just call Edward and he'll give you a push
Hmm so that's why he isn't seen in the show anymore, he's going all around the world pushing other engines upper the hill....
@@stingky3689 that’s a better explanation than Mattel gave
Edward Bros. Banker Co.
Or why not use the similar mechanisms being use to take the rollercoaster to go upward before going downhill.
@@okamijubei Well the Snowdon Mountain Railway uses a system kinda like a rollercoaster! Though instead of having the chain move the train the train uses static teeth to climb.
This is why mountain rail lines are impressive. Two that come to mind are the Copper Canyon Line in Mexico and the Hakone Tozan Rail in Japan.
I'll never mock Gordon for needing Edward to go up Gordon's hill again.
You got this big habit of taking something hard to understand and make it easy. Good Job.
This is a very helpful video for those of you who wonder why Gordon keeps getting stuck on his hill. Now, I know some of you would chalk this up as Gordon being lazy. But even times where Gordon actually tries, he still gets stuck.
Now, this can depend on how many passengers ride the Express, the number of coaches Gordon pulls on a daily basis and how quickly he travels with the Express. Considering that the Express coaches are based on the BR MK1 passenger coach, a single one of these coaches can seat 48 passengers. And in the series Gordon is typically seen pulling 5 coaches and one brake coach. So with a packed Express, Gordon would be carrying 240 passengers and their luggage, along with the Guard in the brake coach. A single BR coach weighs 27 long tons, or 60,480 lbs in US terms. And considering that there is a total of six coaches in total on the Express, Gordon would have to be pulling a total of 362,880 lbs or 162 long tons. So yeah, it's no surprise Gordon keeps getting stuck on his hill. He'd have to be moving at a fairly decent speed to make it over his own hill. Take Gordon's his brother, the Flying Scotsman, for example. Scotsman can easily reach 100 mph, and considering that Gordon is an A1 Pacific, it's possible that he is capable of reaching the same speeds. However, the Express does have a speed limit as to how fast it can go. So in order to make it over the hill, without a back engine, like Edward, he'd have to maintain a constant rate of speed without stopping, in order to avoid getting stuck. I'd say something around 60 mph, 75 at most. (Hopefully this provides some insight.)
On 2.65% it's 2.65% the gravity of the whole train turns to drag and for a 250 ton train (the loco itself weights 92 tons) it's 66.25 KN of drag. A1 can do 132KN so he should be still able to pull it off although it would be really slow and probably need sand.
However if the train is heavier than this it might not be that lucky for Gordon. Imagine 5 Chinese passenger seaters packed with 200 passengers inside each of them?? (Search for Spring Festival Rush if you can't imagine) It would be 66 tons each. Yikes.
@@phoenixarian8513 I guess it's a good thing that Gordon's Hill only has a gradient of 1.75%, then.
The breaks have a much larger advantage over the acceleration when it comes to trains as only a few of the many wheels apply power to accelerate, but all the wheels can apply breaking force.
Yes, and all the train cars that follow behind supply braking force and rolling friction from their wheel bearings.
Brayks
@@krakenwoodfloorservicemcma5975 Brakes
@@krakenwoodfloorservicemcma5975 Brakes
@@krakenwoodfloorservicemcma5975 Brakes
I've heard becoming a locomotive engineer requires lots of training.
+Wayne VanWeerthuizen
Oh railly?
+Victor Korgoth I don't think you got the joke.
Sorry if you did ^_^
AirCommando12
I think he did, as his last word was dis-trac-ted ;) .
***** Oh yeah...Stupid me xD
AirCommando12
Hehehe. It took me a few moments too :) .
Small mistake in the video: at 4:07 he says the "tractive force remains the same" on the incline. This is not true. It actually becomes less (making it more challenging for trains to climb hills. In physics terms the force of friction is equal to coefficient of friction (steel on steel) multiplied by the Normal (support force). This Normal force become less on an incline.
Here in the Appalachians we have a few lines with over 10%, and freight gradients are also 3-5% generally. It just proves the technological marvels that are modern trains.
They probably don't have too heavy of a load compared to the USA or Mexico freight trains that have 120 to 180 wagons and at least half are double stacked. The greater the load, the more torque is required, and to transmit that torque you need more friction.
You know who’s really into trains? Vice President Harris.
@@Brandon-uy1uv the Appalachian mountains are literally in the United States, where those mile long trains operate
Can jeremy drive a train uphill ??
Next time on top gear
*Cancelled*
Back with The Grand Tour.
Why don't you watch the grand tour? lOL
Answer: No, because he's Jeremy Clarkson and all he'll do is try to use POWER! and SPEED!
Jeremy: Speed! Oh no... It is going up slower now!
James: Of course it is you pillock.
IoI
James May: *Sees train at the bottom of a hill *
"Does that mean he's not coming on, then?"
At least you tried to be funny
Hats off to you pal
You utter legend
one litle comment: The weight pressing on the tracks is reduced when going uphill/downhill (you can split the weight into the component parallel to the tracks and the one orthogonal to it. When perfect leveled the orthogonal one is 100% but when going up a 30 degree angle it is only 50%
+Christian Kunert Thinking about it in my head wouldn't the force becoming down over an area aft of the contact patch of the wheels on an incline where on level ground its coming down overtop of it?
Me, who lives on a mountain town and takes the train every day to the university :"really?"
For those of you who are confused as to how a locomotive will gain traction in the first place (since like he said steel on steel has little friction), locomtives will use sand to gain a grip on the rails, and as it gains speed, sand is no longer needed. Sand is also used on a locotive's wheels when tackling an incline.
sand is used by TAP Dancers as well.
"Why can't trains go uphill?" Not with that attitude.
not with that "Altitude"
@@williamchapman2371 ha I see what you did there
The Snowden mountain engines and the Cody fell engines can
Attitude also means heading, so if you train is going slightly up its attitude is raised, and therefore cannot climb a hill with that attitude.
What about "I think I can, I think I can.." clearly we need more "can do" and less moaning from British trains...
Bruh i used that profile pic
Too be honest how hard is it to activate a chain lift lol to get the Train up lol no need dig tunnels and make the ground very unstable
@@jonathanoxlade4252 is the chain lift you are talking about what roller coasters use during that initial steep incline of the ride? (i look back at this question and i think to myself..."duh, moron..." but nevertheless, i'll just make sure i understand- and, yeah, why don't they do the chain lift?)
@@josephaether377 imagine that chain breaking
Better solution there is cog railway. There are even some that engage the cog only where needed.
But as for why not: it’s super slow, high maintenance, not particularly efficient or high capacity and did I say super slow? It’s really only an option for passenger railways that are intentionally climbing a mountain. If you’re just passing through a mountain range with freight, the tunnels etc are more efficient.
I knew this already from playing Railroad Tycoon in the 90's. I even knew what the max. gradient would be. It's one of the most important factors when laying track. Funny how that "game" taught me about railroad engineering as well as the stock market, etc.
Yeah that game is an excellent teacher. Sometimes I have to use dirty commercial means to crush rival companies...
Some trains shoot sand directly in front of the drive wheels to increase traction.
Claude Smoot That's more for snow or ice, or if the wheels are sleeping while pulling heavy load. It wouldn't help much for hills
Alex you dont know shit, i have climbed steep hills with the aid of sand.
@@TrainsfanAlex6060 how would that not help for hills? Sanding is a method to gain traction, it doesn't discriminate whether you're on a hill or not...
@@ThePedro8161 The amount of sand is limited. Trains plan to climb hills without sand and only use it when rail conditions are bad or some bleeeeerp railway guy sets signals in a way that forces a Pacific (not the best hillclimber) to stop on a Hill (they used a BR52 as a pusher in the end)
@@mbr5742 that is not true, locomotives hold loads of sand and use the sanders often when climbing steep hills.
A few years ago I was going down a 14% grade in the Rocky Mountains and saw a freight train coming up the same grade on the tracks next to the road.
If you get out in that part of the world (and I presume in the Alps), you will see lots of trains going up some pretty steep grades.
Continental divide.. I worked in the Montana region. You are correct, they handle very steep grades.
I used to live in Chamonix Mont Blanc (French Alps) and the main line going through the valley has to climb up a 1 in 11 gradient on part of its route. That's all friction based, using light weight trains, wikipedia "Saint-Gervais-Vallorcine railway" if you're interested.
There are much steeper trains in/around the valley but they use rack and pinion.
I honestly think James has all of this knowledge in his head already. I wonder how much research he truly has to do to produce a show like this. Say what you want about his choice of shirt or his lack of forward speed, but this man is a true joy to watch. Especially when it is something he is passionate about.
James: "..if you're a qualified railway engineer."
Me: *Smiles happily*
This makes the Little Engine that Could even more epic
The best locomotives for tackling grades are American geared steam locomotives (the Shay, the Heisler and the Climax locomotives). I have heard of a Shay going up a 14% grade before. That's why they were so popular with logging railways. If you haven't heard of aforementioned locomotives, I then suggest you look them up. They're really quite amazing!
And those locomotives with rack rails and pinion wheels, they can climb mountains with 2% grades.
Shays are amazing, i've seen the ones running on Cass Scenic (which has a 11% grade).
James May, you completely forgot that us Americans have locomotives that can go uphill (very slowly) with great ease! The Shay, Climax, and Heisler locomotives can conquer grades of up to 9% by way of geared wheels. Some even have two gear transmissions. Even though they're very slow, they still get the job done, especially in logging country, as opposed to rod driven locomotives. The Lickey Incline has had it's fair share, but it's nothing compared to grades like Freighthouse Hill in Tacoma Washington for example (3.5% Grade, and took a rod engine and an GM-EMD F9A to tackle it with a four car excursion train two-and-a-half years ago; that's fire and thunder there!).
Good explanation though sir, and now if you'd be so kind to explain why we have no "Flying Boats" of substantial size anymore, or why we are attracted to gaudy cruise ships, over proper ships like ocean liners? Then I'd most definitely be thrilled. Cheers sir, cheers. Complements to your airship video too.
For that matter, he mentions the Eurostar, which partially runs on the french high speed network. Both TGV's and 3rd generation german ICE trains run on routes with a 4% gradient without any special adaptations at all... And special purpose geared locomotives can go up steeper slopes than cars can handle...
the shay goes up 11% at the top of cass
KuraIthys That is because passenger trains are shorter.
Steven Michael Well, maybe...
Freight trains are in general longer than passenger trains, but even if they are not, they are often heavier regardless.
But, the thing all these high speed trains tend to have in common, is well, high speeds. Many of the steepest gradients on high speed routes are momentum gradients, which trains can only actually climb consistently if they're going fast enough to get to the top through momentum alone.
The German ICE routes also show the impact of distributed traction. The Cologne-Frankfurt route has 4% gradients. ICE 3 trains can run over it with ease, but ICE 1 & 2 trains are not allowed on the route. Even though they could make it over 4% gradients when at speed, they are not allowed on the route because if they come to a complete stop for some reason, they would at best manage a 3.5% gradient. The ICE 3 has a higher power to weight ratio than the older two versions, but it also distributes that power over the entire length of the train, with every other car being powered, and 50% powered axles overall, compared to just 8 out of 56 axles (~14%) in an ICE 1 being powered, or 4 out of 32 (12.5%) in an ICE 2 set...
Yes, short line railroads especially have to take runs at hills. Inertia = Efficiency. I'm not sure where you live, but in America, most passenger trains have about 10 cars while freight often have over 100. Also, passenger trains use locomotives that are made for acceleration rather than power. Lastly, as you said high speed trains run fast (no kidding!) and bigger speeds mean less traction.
Best Regards
For something I never gave any thought to, this was very informative.
Another solution is to spread traction power accross the train. At the German ICE 3 for instance, it can maintain 300 km/h (185 mph) at a gradient up to 4% because of the traction power being divided along the train (it also allows quicker acceleration)
For those of you who don’t understand, the German ICE has AWD
Yes MU rushes through grades with ease because he has the full train as weight. For conventional setup if the train is too heavy and the loco is too lightweight it won't move even if the loco has a superman in it. It's the problem of traction like pushing a heavy box on ice. Your feet will slip and the box will never move.
However MUs are expensive to use therefore it's only good for HSRs. Freighters have little profit in each haul and using MU as freighters would eat all your profits. Sad truth. Freighters can't afford MUs and had to use conventional setup.
@@phoenixarian8513 Well, nearly all Dutch domestic trains have the MU set up and by somewhere next year, all have.
@@SpeedBird6780 I've heard europeans have so little freight loads that the semitrucks are gonna do this job instead. If there's only a handful of them to deliver some high value cargos such as automobiles this will still be affordable.
Just thinking about delivering some heavy items such as COAL or IRON ORE with MU makes the treasurer scream.
@@phoenixarian8513 I was talking passenger services, freight services still all have locomotives run it (obviously). It wouldn't be feasible, even in Europe, to run MU set-ups on freight trains as usually, there are cars with multiple destinations on one train and that needs to be exchange. I thought I was pretty clear that I was talking passenger services in my previous comment.
I always thought it was unfair that the 'Leaves on the line', and 'The wrong kind of snow' explanations for delayed trains in Britain were mocked by the media.
The new snow-clearing machines (imported at great cost, no doubt) were designed for shifting overseas-type snow - the kind of light to medium powder that forms 12' deep drifts in places like Finland and Canada. The lovely, new-fangled snow-blower/scrubber/whatever devices worked brilliantly on that stuff.
BUT... In Britain the snow may only be 6" deep, but it's almost never powdery. No, no, no. It's 5" of dense grey sludge with an inch of beautiful crystal clear ice on top of it. Yummy! Trains don't like it. Snow-clearing devices don't like it, even the massive Russian flamethrower-type ones. Ye olde steam locomotives could be modified to chisel it up as they went, but modern units are set up differently and crud on the line is a real problem. So much for progress.
Wet leaves on the line are another ridiculous-sounding but genuine disaster because they squish down into a kind of greasy plywood that reduces traction to zero.
British 'wrong snow' is a pain to shift. Bear in mind that 'winter' here lasts for 5 hours on a Monday, then reappears two days later for 16 hours, before bright sunshine takes over until teatime, followed by winter 2, where snow falls, freezes, melts by lunchtime, refreezes by teatime, clears completely after a day of blazing hot winter sun/fog/sleet/hail/rain, then gets topped up by snow in time for lunch the next day, which turns to 3" of ice overnight... etc.
In Canada you can plan for winter. Properly. It lasts for blooming months. Snow tyres or chains on the car; full-time track-clearing machines for the railways... In Britain it comes and goes totally unpredictably. Can't use snow tyres or chains on the car because the roads change from ugh to aargh overnight. Sometimes winter's quite warm and sunny. For three hours. Everything melts. Yay! Just before a five day ice-storm which brings down all the power lines. Boo. But which then melts overnight. Sometimes. So investing millions of quid in fancy, Arctic-spec snow-clearing gear for the railways is one hell of a gamble. Yes, I know it sounds like a stupid cop-out, but them's the facts.
The way you shift so-called snow hereabouts involves 6 guys with pickaxes, shovels, and huge mugs of hot, sweet, milky tea, walking ahead of the train as if it were still 1885. So when the rail official (perhaps foolishly) told the journalist that the trains weren't running because the wrong kind of snow was on the line, he was being absolutely honest, which is never a good idea when dealing with the British media.
So a train can be halted by a simple pile of leaves? I will harness the power of nature and its leafy friends just to screw over the passagers. *evil laugh*
But seriously though,trains and slippery surfaces don't mix.
Also, in the rare occasion that the UK gets fine powder snow, it gets sucked into the traction motor cooling system and melts right in the heart of the electric motors. Shorting them out.
All of this is true but I am still unimpressed that the country that invented the railways and was the cradle of the industrial world, famed for its industry and ingenuity could not scrape a few wet leaves and a bit of snow off a railway line.
@@Chadmiral Wet leaves can give trains flatties as well. Really they are flat spots rather than flat tyres but it's just like in F1 if a driver skids too much when braking the friction flattens the wheel causing vibrations. The wheels need to be reground when this happens. In F1 at least you can just change the tyre.
Interesting...
The Rimutaka Incline on Wellington New Zealand operated by steam locomotives for 80 odd years on a line with a gradient of 1 in 15. It's amazing how little the engineering enthusiasts of the world know about the little railway. It used a centre raised rail with horizontal cog-like grip wheels to help the locomotives climb the hill on the return journey.
The same centre rails were used for supplemental grip on the descent.
Look it up!
Here's a video of them in action. There is a full feature length one lurking around somewhere bit I think it keeps getting taken down.
ruclips.net/video/DSCDfXiDNI0/видео.html
This explains how the engineering worked, much better than I could anyway.
ruclips.net/video/CZ57ul1vkzw/видео.html
Same with Odontotos rack railway in Greece!
I appreciate the subtle nod to Monty Python’s Flying Circus.
Technically, the traction force does reduce as the grade increases. (By the cosine of the angle.) It's small at railroad grades, but still there.
This makes me appreciate "Gordon's hill" on Thomas the Tank Engine.
Ha Ha
🤣😂
Yep
That's the reason I clicked the video.
James may acctually watched ttte when he was a kid
Just a small point. When trains came about in the 1800's, many engineers tried to come up with alternative systems, like rack and pinion, that would increase traction on rails because of the idea that a train on a rail would meet and an extremely small, and theoretically infinitely small point, since the intersection of a circle with a line is such. This continued until a scientist was able to show that this is not in fact what happens at all.
If you take a steel ball and bounce it off concrete, you will see what happens. It bounces. Rubber bounces because it flexes and returns the energy to the ball to bounce it. Steel flexes as well, but it is so resistant to flexing that it flexes much less, but it takes much more force to do that. However, the force imparted to the steel ball is returned to bounce the ball again, in proportion to the force imparted. This is why that steel "clack clack" toy works.
When a rail car meets the steel rail, it actually flattens under the force of the weight of the rail car. It is not much. The contact point is about that of a dime. However, even that point of contact, under the tremendous force of the weight of the car acting on such a small point of contact is enough to flatten the steel and actually make for a pretty good, if temporary, contact with the rails.
yes indeed!
And then the contact area shrinks when the train is unloaded? Or the train itself causes this compression?
@@jshepard152 no, the only traction that matters is the driving wheels on the locomotives, which pretty much always weigh the same.
@@ThePedro8161 - Until you want to slow or stop the train. Then every wheel has brakes, so trains can stop in a much shorter distance than they can accelerate. On passenger trains that have electrically controlled brakes the emergency stopping distance is much shorter than freight trains that have train line (the pipe that supplies compressed air to the brake system on each car) controlled brakes.
Why lie?
There is a town in Utah, USA called Helper. This is because the steep climb trains would have to make in the area necessitated “helper” engines to do so.
What about the Little Engine Who Could?
Well! He grew up and now he can't no more.
It was made of paper or celluloid and imagination. The latter can scale anything.
Really? I've tried , but the latter couldn't scale my fish.
Yes he did x 3
Dan Lewis are you sure you don't mean the little blue embarrassment?
Hill:exists
Thomas the tank engine:you dare opose me mortal
Lmao
I was expecting Clarkson to come in the comment section and type "this is the most boring thing on earth after May driving on the track" or something like that
Or just POOOOOOWWEEEEEEEEEEEEEERRRRR!!!!!!!!!
This brings me memories of Gordon's hill. That hill in the video makes Gordon's hill look like a nice hill.
You can use cogs to power the train up steep hills. That's what trains are doing in the alps.
Reading visual novel about old steam trains, and this information actualy helps me understand the material even more.
Thanks. Old steam locomotives are just great beings.
4:14
With this blow to The Little Engine That Could, my childhood is officially dead.
I think the people that wrote the story knew what they were talking about.The Little Blue Engine is a switcher engine, which has more power and traction than your typical locomotive. That was why it was the only engine that could get over the hill.
The unrealistic part of the story is the idea that anyone would be dumb enough to run a train track straight over a hill.
Does Jeremy know you are out playing on your own?
Clarkson is the only one who doesn't go out playing on his own. May has had a bunch of other shows on BBC and Hammond had Brainiac
Jeremy did some great military documentaries.
G96Saber Oh really, do you know what they're called? I gotta see it
Lucien Lachance Jeremy Clarkson War Stories. I believe they're on RUclips.
G96Saber thanks matey
While it is abandoned for now, the steepest standard gauge mainline climb in the U.S. is Saluda Grade, originally owned by the Southern and eventually Norfolk Southern until it was abandoned in 2002 I think. With the worst of it being 4.9% for a hundred yards and the average reaching 4.3%, the gradient was often a railfan favorite. Don't worry about it being turned into a railroad trail (a walking path that travels along ripped up lines), I hear NS has sold the property to a short line railroad who wishes to bring the gradient back to life.
Where did you hear that NS sold Saluda? Last I heard they still own the right of way with no plans of sell it or reactivating it.
In all my life I never thought of this. Thank you 2013 BBC and James May.
I never lost a minute of sleep worrying about whether or not a train could go uphill. Does that mean I'm a nasty person? Will I rot in hell forever?
Thanks James, absolutely fascinating. Never knew that!
The point about how little the contact surface of a train to the tracks is, may be one of my favourite facts ever.
James May is 1 of my 3 favourite TV presenters. The others being Jeremy Clarkson and Richard Hammond of course.
Nice presentation.
Trains can go up hill.
1. The Stoosbahn is a FUNICULAR railway with a maximum gradient of 110% and is the steepest funicular railway in Switzerland and in Europe.
2. Katoomba Scenic World is a steepest CABLE railway in the world with a gradient of 128%.
3. COG trains. The Pilatus Railway is a mountain railway in Switzerland and is the steepest rack railway in the world, with a maximum gradient of 48% and an average gradient of 35%.
The first mountain cog railway was the Mount Washington Cog Railway in the U.S. state of New Hampshire.
4. Lisbon Tramway has gradient of 13.8% in Lisbon, Portugal.
5. Pöstlingbergbahn in Linz, Austria has a maximum grade of 11.6% and is one of the steepest adhesion railways in the world.
Because you did not talk about Funiculars, Cable trains, trams or Cog trains or about trains with extra adhesion.
Last is a train with no rack system.
6. Montreux-Oberland Bernois railway (abbreviated MOB) in Switzerland has a gradient 7.3% Trains can beat this railway.
Funny thing.
Taken to its logical conclusion as the slope becomes vertical, a funicular becomes an elevator.
Yea but you took the bait thats why its a trick question. He means reg trains like the UK/EU uses Steam engines still and the USA uses mostly diesel-electric and sumtimes they use steam. We all know cable cars and COG trains that were specially built to go up steep incline.
Funiculars have geared wheels and rails and are not considered regular rail. The maximum incline for ordinary trains is 30 permils while metro EMUs can up to 35.
Definitely recommend taking a trip on the cog railway up Mount Washington. Cool experience!
James May-
Trains can’t go up a steep hill.
Cog railway train-
Hold my beer.
Jealous? lol
He is clearly talking about standard passenger and freight trains that run on starndard smooth rails, not rack and pinion trains that are specifically designed for going up gradients standard locomotives can't.
To go up steep hills, there are special locomotives with wheel-sets having a gear that engages the gear rack fixed to the sleepers.
Cog railway
Trains are ultra awesome and beautiful things.
They are indeed :)
A streamlined steam engine would easily get up the hill without any problems unlokia
Sonny Lindfield not as good as cars
no, not at all!
friction limits trains:
if angle_tohorizontal axis > arctan(friction_coefficient) then they would have no grip anymore.
the friction coefficient at steel touching steel is ~0.1
lets assume we can achieve 0.15 with extra sand:
alpha_:horizontal = arctan(µ)
tan(alpha_horizontal)= hill_gradient = µ
*hill gradient* = *k* = *tan (alpha)* = µ
->k= 0.15 = 15%
proof:
example: train climbing a hill with angle of b; the force on the wheels shall be equal to the max. traction force(->max. friction)
Then as mechanical engineering tells us:
*a)* Sum(forces in x)= m*a
+ F_r_friction - mg* sin(b)=ma
special case: a=0 -> max angle:
->F_r_friction= mg sin(b)
*b)* Sum(forces in y)=0:
+F_normal - mgcos(b)=0
F_n=mg cos(b)
1)-> Fr_friction= µ * F_n = µ * mgcos(b)
2) Fr_friction = mg sin(b)
Fr_friction=Fr_friction
µ mg cos(b)= mgsin(b)
µ= tan(b)!
if µ>tan(b) -> train can go up steeper than angle of b.
if µ train cannot climb the hill with angle of b.
Just like Donald Trumps hands then.
I was a Locomotive Engineer for a major Railroad C.S.X. and you are right about wet rail or leaves on the rail all slippery conditions but whenever I had slipping wheels or spinning out of control wheels I would use my SANDERS .It helped most of the time NOT ALWAYS but most of the time !
Tractive force goes down on an incline because the normal force goes down... it doesn't stay the same.
+scowell small angle approximation mate. cos(2.65deg)=.9989
+Nathan Colgan Right! It doesn't stay the same.
+scowell came here to say just that. So the part of the weight that pulls back on the train also doesn't push down on the wheels anymore so you could say the incline is a double edged sword. Oh and another mistake: max speed is when the sum of the air drag and the wheel drag equals the traction force not just the air itself.
+scowell I'm not sure why he mentions the contact area either, when discussing traction. In most cases, it's not a significant factor, right? It's all about the normal force
0dWHOHWb0
I thought so too but apparently the surface does matter: or at least when rubber and asphalt are in use: wider tires, better traction. But I think that's because the rubber kinda adheres to the surface and so you cannot apply the F=u*N formula. So idk how that works in trains but still..
When I was training to be a conductor in Seattle, I took a coal train over the mountain, to the east. We had just gotten to the top of the mountain, and found ourselves at an absolute signal that was red. The engineer was stopping the train, but it was still rolling about 2 MPH. It was snowy, and icy. I was shitting my pants. It finally came to a stop before we reached the signal.
Last year, I was the conductor on a train (lite power). We were going 60MPH and came up to an absolute signal that protected a diamond was all red around a corner. I freaked out and dumped the train (2 engines) and we went from 60MPH to stopped within 500 feet.
Got to love those Cascade Mtns.
You shouldn't have been going 60 miles an hour if it was red...
Really shouldn't be doing 60 on lite power either
Wirelesshotshot mate, that must have been scary as hell, hope your still a conductor. Stay cool man 😎👍🏻
Thank you BBC Earth Lab and very nice James, but one question remains.... Does this effect a magnetic train?
*Nice video. Thanks for Sharing. Love from Vietnam*
Jeremy Clarkson “I was going to get James May to explain why this was so but I’m afraid I went into a deep sleep”
Clarkson wouldn't understand why trains can't go uphill. He would just yell, "POWERRRRRRRRRR"
So the easiest solution to going up hill is to add rocket stages to the train.
What could possibly go wrong?
You just made my day.
+xzx No he watched to much TopGear
SPEED & POWER!
Wont work, not nearly enough thrust. Fully loaded Trains can weigh as much as FIVE Navy Destroyers. So, we have the weight of three warships on roller bearings. The rocket wont do crap.
Br!an, how hard can it be.
Train wheels can't melt steel beams.
but the train fuel can
No, but they can wear them down - if they spin in once place fast and long enough.
True. I saw a photo of a section of damaged track in the US where a coal train had come to a halt, but the Distributed Power locomotive either in the middle or on the rear of the train had not received the command to stop and the wheels had ground themselves into the track. There were twelve wheel ruts in the track at two distinct locations corresponding to the two bogies. It was a real mess and that loco would have been pretty stuffed too. I suspect that the train engineer may have lost his job over that one.
No one gets it. But its okay I got it lol
+Jean Paul IX Megatron They think its about trains lol.
You're a very good teacher. Keep doing more videos
That explains why trains were always getting stuck on Gordon's Hill!!!
come on that's like a 4 degree incline! and yet the banker is either a J70 or a K2 larger seagull.
+Shane Fell
Gordon from Thomas the Tank Engine?
+carultch Yes, they are talking about an Ho scale model of a blue A3 pacific from a childrens show.
@@anfasharchive3244 Pacifics. They Run away from any incline (but FAST). Hills are for 1Eh2' or 1Eh3' engines (2-10-0) like the 40 and 50 series Einheits-Dampflokomotiven
Two important factors at least with North American freight hauling locomotives is distributed power and the ability to motor them independently and the fact that very few freight trains attack the grades seen in the places like the Rockies with out a full compliment of sand in their hoppers.
This guy has a voice like christmas pudding!
he drives like his tires are stuck in christmas pudding
Lucien Lachance ... and yet I bet that he can beat you (or me) in a race ... nothing is what it seems ;)
jorgeferreira2009 obviously he could. i was just telling a joke playing on the fact that he's known as Captain Slow
Tommy McCusker sweet and sticky?
this CONKER is Christmas Pudding.
Very well done! Simple but not condescending.
There are 2 types of brakes on modern locomotives, the air brakes and the dynamic brakes. Dynamic brakes in simple turn the traction motors into generators. So the locomotives do most the work air brakes are only used if the train starts going to fast.
What James forgot to mention is trains do have a system that can blow sand on the rails just in front of the wheels helping with the traction problem.
I wish he would have mentioned that trains squirt sand on the rail in front of the wheels for traction.
Also, a runaway train can cause the track/wheels to have a thin layer of molten steel which makes it go even faster
Thank you for the educational lesson James May
that's bulllshit ! I laid a 45 degree track and the whole system runs fine. dont belive me ? join my Minecraft server
That's why locomotives have what's called a "sander," to literally drop sand on the rails and create friction. This comes in handy when both climbing hills, and when running during the rainy season. In the earlier days of steam, they would just throw the sand out in front as they ran along, like what the fireman had to do in "Edward's Exploit," for you Thomas fans out there.
This is not without problems of its own, however: in sufficiently wet weather, the wheelslip can turn the wet sand into mud, making the situation even worse than before, as seen in "Leaves." An episode which, coincidentally, revolved around a more hot-headed and less intellectual James.
You paraphrased those stories poorly.
@@caboose.20 I loved them though.
trains go uphill, we have train tracks from Beirut to bekaa, they pass by a 1700 meter altitude passage. Beirut is at sea level, and the length of the trip is about 30 km
Classic Vid!
❤❤
This is why I like James May. He reminds me of what used to be good about England.
What? The genocide and invasions of colonialism?
Greatness indeed.
@@antcawdor the gritty, down to earth working class, the stiff upper lip, the punch a small island can make.
@@murphyjack90 I agree, Ireland certainly is all those things. A very good point, very well made.
@@antcawdor If Ireland were at all like that then we wouldnt have been shat on all those centuries. Come off it man Englands not all bad.
@@murphyjack90 With that last comment, you confirm my first
Thankyou.