Why Can't Trains Go Uphill? | James May's Q&A | Earth Science
HTML-код
- Опубликовано: 18 июл 2013
- James May looks at why trains can't go uphill!
Subscribe: bit.ly/SubscribeToEarthLab
Taken from James May's Q&A Ep 30
Best of Earth Science: bit.ly/EarthLabOriginals
Best of BBC Earth: bit.ly/TheBestOfBBCEarthVideos
The Doctors Are In The House: bit.ly/TheDoctorsAreInTheHouse
Welcome to BBC Earth Science! Here we answer all your curious questions about science in the world around you (and further afield too). If there's a question you have that we haven't yet answered let us know in the comments on any of our videos and it could be answered by one of our Earth Science experts. 
Развлечения
Hill: *exists*
Thomas had never seen such bullsh*t before
Muzzammil Ahmer look out of the train!
lol
*laughs in Gordon’s hill*
@Galaxy Purple Indeed. You can actually here one of the crew saying it during an episode.
@Galaxy Purple I got that from the show
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
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
"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
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
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.
They managed to do a Q&A with James May and keep it at under an hour? Impressive
*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
*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
Hills: *exist
Gordon from Thomas: *sweats nervously
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.
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.
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!
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.
Me, who lives on a mountain town and takes the train every day to the university :"really?"
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
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
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.
@@Brandon-uy1uv You never heard of the Appalachian Mountains in the eastern US? Shame on you.
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
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...
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
1:39 James trying to read the script
Wouldn't make sense cuz he's not wearing bifocals
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.
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 !
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
1:39 That strange face James makes while waiting for his cue.
Thanks James, absolutely fascinating. Never knew that!
I loved this series and i wish James May did more of such stuff
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)
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: "..if you're a qualified railway engineer."
Me: *Smiles happily*
Very well done! Simple but not condescending.
"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.
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
Definitely recommend taking a trip on the cog railway up Mount Washington. Cool experience!
Thank you for the educational lesson James May
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
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.
*Nice video. Thanks for Sharing. Love from Vietnam*
Tis bloody jolly good little explanation there, good sir .
I'll never mock Gordon for needing Edward to go up Gordon's hill again.
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 ;-)
@@Railriderchris 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?
You're a very good teacher. Keep doing more videos
B&O's Cranberry Grade in West Virginia (still used by CSX) has short stretches running about 2.80% and most of it in excess of 2.00%. Helper engines (rear end and more recently DPU) have always been used. For decades, 80 cars seemed to be the magic number for reliable operation, but remote controlled DPU has thrown that out the window.
Then there is Saluda Grade on the old Southern. Average grade was 4.24% for about 2.5 miles and there was about 300 feet of track with an astounding 4.90% grade! Going down was as much an adventure as going up. Successor Norfolk Southern took the line out of service in 2001 although to date it is not officially abandoned.
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
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 something I never gave any thought to, this was very informative.
Manitou and Pikes Peak cog railway (on the incline of the mountain Pikes Peak, highest rail in the world) is currently being restored and will re-open in 2021! If you ever visit it is a wonderful journey... worth the experience.
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
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.
Still love this many years later!
Useful every time I play TSW4!
Here in the good old U.S.A., we had a train that climbed a mountain. I rode The Mount Washington Cog Railway to the top of Mount Washington in 1960, and drove an English Ford Cortina GT to the top in 1968.
The Cog Railway closed down after a big crash, and the Cortina GT was re-poed.
You got this big habit of taking something hard to understand and make it easy. Good Job.
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.
Niiiice G, thats some nice knowledge, keep it up G
I remember learning that the railroad at Walt Disney World’s Magic Kingdom has a slight incline as it approaches Tomorrowland. I was taking the "Behind the Steam" tour and the tour guide pointed out how the train’s wheels were slipping slightly as it went up that incline. It was a very tiny incline (although I can’t remember what it was) but it caused a noticeable problem in three of the four trains in the fleet. Only one of the locomotives could handle it without slipping. I had never thought about this problem before then and now I wonder about it anytime I see a train track in a hilly area.
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.
"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.
The "Big Hill" in BC, Canada was a pretty wild section of track... Remained in operation for 25 years before the twin 3/4 tunnels in opposing mountains were completed - Spiral Tunnels, still a pretty big derailment zone to this day
Classic Vid!
❤❤
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.
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!
This video was pretty helpful.
thank you Sir and i learned something new
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 :) .
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
Good stuff
thank you
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).
This brings me memories of Gordon's hill. That hill in the video makes Gordon's hill look like a nice hill.
1:00-1:10 the smoke effects are hilarious. He seems like he'd turn nd say "Do you mind?" Lol 🤣
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.
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
Well explained.
04:20 As a train guard myself, i can confirm this is exactly how i would explain it. Its one of my go to's, shifts blame
Hill:exists
Thomas the tank engine:you dare opose me mortal
Lmao
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?
I love trains. You do a terrific job of presenting the subject in an interesting manner. By the way: Are you related to Queen's Brian May? I gave you a thumbs-up and subscribed. All good wishes!
No he's not
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.
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.
100% agree having worked for British rail back in the day.
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.
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
You can use cogs to power the train up steep hills. That's what trains are doing in the alps.
i remember playing railroad tycoon and the answer to gradient problems was sand. trains somehow used sand to get more grip when climbing up. at first i though it was through some contraption but my grandpa said that sometimes rail workers shoveled sand ahead the train on the steepest slopes where the train basically went at walking pace.
Instant understanding
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.
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.
I love how theres a geared logging logo in the video...
There is one modern Swedish railway that has some shockingly steep hills for its young age (late 90s/early 00s). Mälarbanan between Arboga and Örebro has hills at 2,5% and allows speeds at 200 km/h, while the normal limit for a new Swedish railway is 1% steep hills.
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 😎👍🏻
James May is 1 of my 3 favourite TV presenters. The others being Jeremy Clarkson and Richard Hammond of course.
Us down in nz fixed the problem.
They are known as the Fell locomotives and they managed a whopping 6.667% incline known as the Rimutaka Trail.
There was a part of rail line between two cities I travel couple times in a year. There was a small city with 50-60k population in the hilly area and even old cars and most trucks would stop and die on the road, smoking, overheated. And trains also would come to a stop and wait for an hour to find extra helper locomotives from nearby stations. But it wasn't always a case as I remember, I don't know what was the variables to make it stop and wait for rescue or to climb slowly. Maybe they would get that extra loco in the last station knowing it would definetely come to a stop if not pushed from back so you wouldn't have to wait for 45 minutes for help. They have changed the roads also the rail line in the past decade, but also cars and locomotives improved; so I don't know if the new line and roads saved them or improvements in the engine tech.
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
Good educational video . Thanks what about the Streaks , Mallard, fast as hell .
Hey that was well done he did good. I learnt more just then about trains then i may ever have and i saw the bullet train episode.
Actually, they can. It just can’t be more than a 4 or 5% grade or it becomes a issue. For example, Norfolk Southern climbs several tall mountains in Altoona, PA.
The point about how little the contact surface of a train to the tracks is, may be one of my favourite facts ever.