@John S he worked in the Cols. Oh plant, it was a typical war era hell hole. 100* or better and oil vapor and burning metal from the heat treat area hanging in the air, Dad said oil would drip out of the ceiling and into their food at times and that they carried guys out of there feet first plenty of times. He set the grinders up, it would be a Sun evening supper time and the phone would ring, it would be his boss asking if he could come in and help them get the machines set up right. He went every time, if I was half as tough as he was I’d be happy. He just turned 85 and has had Parkinson’s for a few years which I’m sure his job had something to do with that but he’s hanging in there. It was better than the coal mines of SE Ky but still a hard way to make a living. If you ever listen to the song readin writing route 23 by Dwight Yoakam it’ll tell you the story of thousands of guys like him. Sorry to ramble, I’m just pretty damn proud of my Dad and all the blue collar people that bust their asses for every cent they make.
Old memory resurfaced @ 1:30 ! When I was a small child in the early 1960s, my mother used a vacuum cleaner that looked exactly like this. I have not seen one like it for well over 50 years. What s trip!
Why is it that I'm becoming emotional over watching an 80-year-old industrial film? Probably because I'm a mechanical engineer that appreciates the foundations of his profession.
My life changed when I was learning Tool and Die by a single book. On my honeymoon I begged my wife let me check out a used book store that had been a really old public library in Branson, MO. "Methods of Machine Shop Work 1898" author forgotten. I learned about originating surface plates, the step-by-step method of originating rotary tables, how to make an errorless screw and many other things. When I returned and reported to my Guru the Chief Modelmaker at Bendix in Kansas said "Wow! You've really improved !" PS - My Dad worked for Professor Moore of Moore Tool Company. He said when we was young he learned to listen very carefully when that great man was talking and to speak only when necessary : D
I worked for Cincinnati Milling Machine later Cincinnati Milacron in the grinder dept back in the 60's. We made 1000's of grinders for all the bearing manufacuters including Timken which was probably our best customer. I ran off many centerless grinders that were used for grinding bearings. Great movie.
Old School Machining back then , and such a high skill level . I run a few Cinicinnati CNC Lathes in my machine shop , all bought from their factory in Birmingham England , which is now sadly long gone
Wow I worked summer jobs two summers at Accroform Metals in Palatine, IL ca 1970 and we used Cincinatti presses, a 100 ton and a 200 ton, and some smaller German presses for forming powdered metal parts. Can you tell me if Milacron is a joining of the words 'mill' and 'micron'?
I probably use some of the machines you built! Cant say where I work or what I make, but I use some ancient Cincinnati grinders that have been retrofitted several times over with new technologies to automate it. CNC controlled dresser profiles, automatic diamond turners, servo driven infeed and plunging, variable mag chuck power, the work speed, finish speed and the whole grinding process can be altered in seconds with a few taps on a touch screen. Roller dressed cutters for conjugate parts. We can maintain a precision of nearly 1-2 tents between pieces. They are old but in a single 8 hour shift I can easily produce over a thousand pieces (when my coworkers aren't holding the cell back).
wonderful. thank you. The sliding friction problem demo was excellent. It reminded me of how the Egyptians moved those huge blocks of limestone and granite.
Excellent demo and that is exactly why the narrative of Egyptians moving huge stones on logs is false. They had a method that is lost in history and was much better than anything we have today.
The first section of ramp only has to take blocks to a height of 35 RC ...the height of the Queen's Chamber floor. A spiral ramp around it can then be used to construct ìt. Do the maths properly and everything becomes clear.
@@firestarter105G Dr. Joseph Davidovitz subjected the casing stones to X-ray scattering spectroscopy and proved that the stones are a synthetic geopolymer. They were cast in place, not cut and moved, hence the perfect joinery.
I'm freaking out that they were able to measure up to millionth of an inch back then... damn. That's the kind of bearing tolerances in modern HDD drives... really impressive.
Joseph Whitworth, of Whitworth thread fame introduced the world to his "millionths of an inch" measuring machine at the Great Exhibition in London in 1851. The "modern" ball bearing was created in Wales by Philip Vaughn in 1794.
@@billdoodson4232 Thank you for telling us. The bearing as we know it is so versatile that without it we would not have so many items in our lives, eg. the car, bicycle, trains, engines, etc.
@@emanuelmifsud6754 In aerospace engineering, the requirements are within 7 to 8 millionth of an inch in the 1950s and 1960s during the Cold War's space race. Then came the requirements of IC Chips Manufacturing machineries called steppers that calls for MECHANICAL PARTS THAT HAS TOLERANCES OF 25 MILLIONTH OF AN INCH OR MORE. It is unfortunate that many young Americans are so under educated that one American FALSELY called me of lying even when I told him to read books printed in the 1950s and 1960s and 1970s and 1980s and 1990s on the engineering requirements of the aerospace industry and IC Chip Stepper Industry. But his American arrogance resorted him to more belligerent arrogance against me so I called him AN AMERICAN IGNORAMOUS! LOL! American kids, dumber than dirt Warning: The next generation might just be the biggest pile of idiots in U.S. history By Mark Morford, SF Gate Columnist Wednesday, October 24, 2007 Printable Version Email This Article I have this ongoing discussion with a longtime reader who also just so happens to be a longtime Oakland high school teacher, a wonderful guy who's seen generations of teens come and generations go and who has a delightful poetic sensibility and quirky outlook on his life and his family and his beloved teaching career. And he often writes to me in response to something I might've written about the youth of today, anything where I comment on the various nefarious factors shaping their minds and their perspectives and whether or not, say, EMFs and junk food and cell phones are melting their brains and what can be done and just how bad it might all be. His response: It is not bad at all. It's absolutely horrifying. My friend often summarizes for me what he sees, firsthand, every day and every month, year in and year out, in his classroom. He speaks not merely of the sad decline in overall intellectual acumen among students over the years, not merely of the astonishing spread of lazy slackerhood, or the fact that cell phones and iPods and excess TV exposure are, absolutely and without reservation, short-circuiting the minds of the upcoming generations. Of this, he says, there is zero doubt. Nor does he speak merely of the notion that kids these days are overprotected and wussified and don't spend enough time outdoors and don't get any real exercise and therefore can't, say, identify basic plants, or handle a tool, or build, well, anything at all. Again, these things are a given. Widely reported, tragically ignored, nothing new. No, my friend takes it all a full step - or rather, leap - further. It is not merely a sad slide. It is not just a general dumbing down. It is far uglier than that. We are, as far as urban public education is concerned, essentially at rock bottom. We are now at a point where we are essentially churning out ignorant teens who are becoming ignorant adults and society as a whole will pay dearly, very soon, and if you think the hordes of easily terrified, mindless fundamentalist evangelical Christian lemmings have been bad for the soul of this country, just wait. It's gotten so bad that, as my friend nears retirement, he says he is very seriously considering moving out of the country so as to escape what he sees will be the surefire collapse of functioning American society in the next handful of years due to the absolutely irrefutable destruction, the shocking - and nearly hopeless - dumb-ification of the American brain. It is just that bad. Now, you may think he's merely a curmudgeon, a tired old teacher who stopped caring long ago. Not true. Teaching is his life. He says he loves his students, loves education and learning and watching young minds awaken. Problem is, he is seeing much less of it. It's a bit like the melting of the polar ice caps. Sure, there's been alarmist data about it for years, but until you see it for yourself, the deep visceral dread doesn't really hit home. He cites studies, reports, hard data, from the appalling effects of television on child brain development (i.e.; any TV exposure before 6 years old and your kid's basic cognitive wiring and spatial perceptions are pretty much scrambled for life), to the fact that, because of all the insidious mandatory testing teachers are now forced to incorporate into the curriculum, of the 182 school days in a year, there are 110 when such testing is going on somewhere at Oakland High. As one of his colleagues put it, "It's like weighing a calf twice a day, but never feeding it." But most of all, he simply observes his students, year to year, noting all the obvious evidence of teens' decreasing abilities when confronted with even the most basic intellectual tasks, from understanding simple history to working through moderately complex ideas to even (in a couple recent examples that particularly distressed him) being able to define the words "agriculture," or even "democracy." Not a single student could do it. It gets worse. My friend cites the fact that, of the 6,000 high school students he estimates he's taught over the span of his career, only a small fraction now make it to his grade with a functioning understanding of written English. They do not know how to form a sentence. They cannot write an intelligible paragraph. Recently, after giving an assignment that required drawing lines, he realized that not a single student actually knew how to use a ruler. It is, in short, nothing less than a tidal wave of dumb, with once-passionate, increasingly exasperated teachers like my friend nearly powerless to stop it. The worst part: It's not the kids' fault. They're merely the victims of a horribly failed educational system. Then our discussion often turns to the meat of it, the bigger picture, the ugly and unavoidable truism about the lack of need among the government and the power elite in this nation to create a truly effective educational system, one that actually generates intelligent, thoughtful, articulate citizens. Hell, why should they? After all, the dumber the populace, the easier it is to rule and control and launch unwinnable wars and pass laws telling them that sex is bad and TV is good and God knows all, so just pipe down and eat your Taco Bell Double-Supremo Burrito and be glad we don't arrest you for posting dirty pictures on your cute little blog. This is about when I try to offer counterevidence, a bit of optimism. For one thing, I've argued generational relativity in this space before, suggesting maybe kids are no scarier or dumber or more dangerous than they've ever been, and that maybe some of the problem is merely the same old awkward generation gap, with every current generation absolutely convinced the subsequent one is terrifically stupid and malicious and will be the end of society as a whole. Just the way it always seems. I also point out how, despite all the evidence of total public-education meltdown, I keep being surprised, keep hearing from/about teens and youth movements and actions that impress the hell out of me. Damn kids made the Internet what it is today, fer chrissakes. Revolutionized media. Broke all the rules. Still are. Hell, some of the best designers, writers, artists, poets, chefs, and so on that I meet are in their early to mid-20s. And the nation's top universities are still managing, despite a factory-churning mentality, to crank out young minds of astonishing ability and acumen. How did these kids do it? How did they escape the horrible public school system? How did they avoid the great dumbing down of America? Did they never see a TV show until they hit puberty? Were they all born and raised elsewhere, in India and Asia and Russia? Did they all go to Waldorf or Montessori and eat whole-grain breads and play with firecrackers and take long walks in wild nature? Are these kids flukes? Exceptions? Just lucky? My friend would say, well, yes, that's precisely what most of them are. Lucky, wealthy, foreign-born, private-schooled ... and increasingly rare. Most affluent parents in America - and many more who aren't - now put their kids in private schools from day one, and the smart ones give their kids no TV and minimal junk food and no video games. (Of course, this in no way guarantees a smart, attuned kid, but compared to the odds of success in the public school system, it sure seems to help). This covers about, what, 3 percent of the populace? As for the rest, well, the dystopian evidence seems overwhelming indeed, to the point where it might be no stretch at all to say the biggest threat facing America is perhaps not global warming, not perpetual warmongering, not garbage food or low-level radiation or way too much Lindsay Lohan, but a populace far too ignorant to know how to properly manage any of it, much less change it all for the better. What, too fatalistic? Don't worry. Soon enough, no one will know what the word even means.
The railroads were slow to adopt roller bearings on freight cars because the cars were exchanged all over the country so the cars were paid for by one road but benefited other roads. They used to say these cars with roller bearings would only come back to the owners road when it needed repair so others were getting the benefit of the bearings they paid for. The early use of the roller bearing cars were usually in business where one road controlled the cars from shipper to customer so they always had conrtol of the cars.
You can still see closed box bearings on train cars, but probably only one in a thousand. The roller bearing, identified by the visible turning axle end, has made bearing failure and "hot boxes" a thing of the past.
@@quantumleap359 CSX won't except anything without rotating cap bearings, which makes it difficult for preservations to move old cars to museums without taking the trucks off and loading them on highway trucks as oversized loads. The cost of the cranes is huge.
@@voltairer.2919 solid bearing freight cars were banned from interchange between railroads after 1980. Some hung on working on their home roads into the 80s and beyond, however.
As a kid, my buddies and I traded and competed for marbles. Amongst the most prized marbles were those we called "steelies', something I later learned were ball bearings. It's been fun to see how these were made.
I replaced the turbo on my Subaru WRX from a TD04 journal bearing style to a VF34 roller bearing type. The VF34 being a much larger turbo would normally mean the turbo kicks in at a higher rev range but due to the roller bearing the turbo kicks in earlier giving the car turbo boost from just above idle all the way to 6000 RPM. Roller bearings just work.
If one of those girls gets her high heels caught in the railroad track, well, as the old saying goes, "pulling locomotives with your bare hands is all fun and games until someone gets hurt."
One night driving alongside a Seaboard Coastline RR track I saw a freight car with a hotbox. It lit up the night. I don’t know if it was friction or non friction but it was bright.
@@jockellis I can well believe that. You remind me of a film that used to be shown in England, of a Pacific locomotive on a night express train descending the gradient from Shap summit, braking, with the tyres of the driving wheels showing as bright circles.
IN MY DAYS OF RAILROADING STARTING 1964 IT WAS QUITE DRAMATIC SEEING THE FRICTION BEARINGS SUPPLANTED BY THE ROLLER AND BALL BEARINGS! IN THE CASE OF THE FREIGHT CARS, SITTING ON A SMOOTH RAIL AND BRAKES RELEASED, A PUFF OF WIND CAN START IT ROLLING!!
@@robertholderman7552 IN THE LATE 1960s THERE WAS A ROLLER BEARING EMPTY BOX CAR THAT ROLLED OFF A SIDING BETWEEN HUTCHINSON KS AND DODGE CITY, AND ROLLED FOR 75 MILES BEFORE IT GOT TO A PLACE THAT WAS A LOW SPOT! ABOUT HALFWAY BETWEEN START AND STOP THERE WAS A DEPOT CLERK WHO STAYED MUCH LATER THAN USUAL CATCHING UP ON PAPERWORK! WHILE WORKING AT NIGHT HE HEARD IT ROLL BY AND THEN WENT OUT THE DOOR TO CHECK IT OUT! FORTUNATELY IT WAS A BRIGHT MOONLIGHT NIGHT AND HE SAW IT HEADED EAST! HE PUT OUT THE WORD AND NO COLLISION OCCURRED!
Hi Nick. Nice to see your still doing the train thing. Many happy memories from my Harper's Hobby Shop days. I'm also involved. Latest project is a 15" gauge, 6.25 inch scale Porter. Almost done. Cheers, Lars
"Anti Friction Bearings" ??? Known in Industry as "Roller Bearings" and invented by Heinrich Timken in 1898. Increasingly used in Railway Industry world wide from the 1920's. Particularly for carriage wheel bearings, and in steam locomotive coupling & connecting rods. The loco seen in the programme clearly features the latter.
I used to work as an engineer for a few years for a bearing manufacturer. Although the designs and manufacturing technologies haven't change much since this footage was made, the material technology has advance a long way. In most cases manufacturers have their own secret recipes for their product alloys, usually a mixture of steel, nickel, chrome, manganese and other metals, which have increased the product's life expectancy. BTW, the bearings with the longest life expectancy, they last theoretically forever, don't have any rollers or balls. These are used in the huge generators in power plants and swim on an oil film that is continually pumped under huge pressure between the shaft and the outer race. The friction is allegedly as good as non-existent.
The film is the kind of film we used to watch on those old reel-to-reel film projectors in school in the 1970's whenever I was in school. However most of the films we watched were from the 60's 50's and even earlier the late 40's, and they failed to maintain the old heavy factory heavy flywheel bushing type load bearings. The kind of material those old bushings were made of is actually a soft material made from copper and brass fiber mixture. Those buildings actually had the capability of holding lubricants inside throughout the bushing's fibers, but they used those old glass bulb oil drippers that the machine operator had to keep filled with oil
SKF was not the first - older ball bearings were invented in Sundsvall, Sweden: "The most valuable object we have in the museum" SKF, the Swedish Kullagerfabriken, was one of the companies that brought Sweden into the industrial age and prosperity at the beginning of the 20th century. All school children have had to learn that. But before SKF in Gothenburg, ball bearings were built in Sundsvall, of which probably only one copy remains. You can see that in the museum on Norra berget. Bredenberg's ball bearings were single-row and not mobile enough. Where Bredenberg got the idea from is unknown, but he enlisted a talented Sundsvall mechanic, fabricator Aron Andersson, to help with the practicalities. From the beginning, the balls were turned one by one, so mass production was out of the question. Bredenberg took out a patent for his invention in 1890, and later that year another patent for an improved variant, where the bearing was "specially intended for railway carriages". In 1891 he gathered stakeholders into "Aktiebolaget Kullager", and the following year began commercial production in factory premises where Emhart Glass is now located. Bredenberg experimented further and displayed his product at the Landtbruksmötet in Gothenburg where he received first prize. But already in 1893 the company went bankrupt. - His ball bearing was single-row and not mobile enough, says Jürgen Holoch. Sven Wingquist, who invented the bearing on which SKF was built, was multi-row and thus more mobile. The few ball bearings that Bredenberg managed to sell also did not hold too much load and therefore broke. When SKF started its production in 1907, they used Hoforsstål, the best known at the time, and could make more durable bearings The ball bearing that the Antiquities Association displays in the Craft and Maritime Museum on Norra Berget was donated to the association by a manager of Wallerstedt in the 1930s. As far as the association knows, it is the only thing from Bredenberg's production that has been preserved. - It was one of the first ball bearings made, and not even SKF has one. I think it is the most valuable item we have, says Jürgen Holoch.
There's a machine standing in the museum of FAG Kugelfischer in Schweinfurt, Germany that is claimed to be the very first machine for mass producing precision steel balls for ball bearings. I do suppose though that the idea and invention of ball bearings and their manufacture happened more or less at the same time spontaneously around the world given the profound advantages this technology offered countries aspiring to industrialisation.
At first I went, I’m sorry what ?!? when I saw people pulling a full-size locomotive Then again I remember the Niagara’s had roller bearings and were lighter than other Northern’s But the ability to pull a locomotive is crazy Edit: I didn’t think my comment would get this much attention
Sure glad we exported all of this industry so we could just do the really important stuff, financing the deal to get the deal and then trading options on the deal and creating derivative positions.
I only watched this video because I am a railfan. If this video was shot today the girls pulling the Locomotive would all be wearing Goggles, Hardhats and Orange Safety Vests with a disclaimer saying shot with permission wearing full PPE. The Loco is a New York Central 4-8-4 Niagara one of the finest Steam Locomotives ever produced and the pinnacle of their development. Too bad the President of the NYC RR wanted every one scrapped with none saved for prosperity after a very short service life of only about 10 years as they rushed to switch to Diesel Locomotives in the 50's.
Thanks for the educational commentary B Wallace. I am a rail fan and a history buff. I do not think that this video could be made in the world of today. Due to wokeism. 🇺🇸👍
You are right. Notice all the cars are still old..the car industry took a while to get rolling with new cars when the war ended. However, the ladies definitely have a 1940s look to them, but no reference is made to war production.
Great film, for the tech info AND the 'slice o' life' of America back then. Thanx, Nick. BTW, could you share the actual year this was made? I'm guessing early 40s. Thanx!
They completely skipped the huge improvement shown in the RR "hot box" shot. With the axle turning, it would wear an oval into the bearing, and still run true without faster wear, instead of getting an ever sloppier and bigger hole in the wheel, providing less bearing surface.
My cousin's uncle worked for Alco on the Big Boy I seem to remember my dad and them talking about the Niagara but being so young paid little attention. Lol
Watching this would give you the impression that ball bearings are a relatively recent invention in the US. Design of the modern ball bearings actually invented by a Welshman pre 1800.
I was skeptical of the girls pulling the locomotive, so I did some homework and the simple arithmetic: • the rail industry states that it takes 2 to 3 pounds per ton of "train weight" to start and/or move at slow, switch-yard speeds. • the NYC 4-8-4 "Niagara" weighed 236 tons. • so the four girls need to be capable of pulling with 236 * 2 = 472 pounds, or just 118 pounds of force each! The salient point to the whole thing winds up being the bearing surface of the wheels on the rails. Without that low-friction starting point, you could have frictionless magneto-hydraulic bearings and the train wouldn't budge a millimeter. Try it with a truck with 1/10th of the weight on rubber tires, it won't move without a lot more force.
@@wryanddry2266 Anyone that can walk, and weigh more than 118 pounds, can press 118 pounds. If you can leg press your own weight, (more likely twice) you can do it. Think about it. (When I was in high school, 5 decades ago, I could leg press 550 pounds. That was on the machine.) steve
@@steveskouson9620 Okay, 550 lb for a trained male HS athlete. But they are using one leg at a time. And because of the angle (notice they aren't leaning much against the ropes) the ropes are getting only maybe 20% of the forces they are exerting. Notice the ropes are slack much of the time: each one is exerting a force only part of the time, making the average force smaller. And they are women--not male high school athletes. I think probably the tracks have a slight slope.
And yet ultra precise spindles turn in either very special plain type journal bearings or hydrostatic bearings. The bearings in an automotive engine are plain bearings
The crank is machined with holes that allow oil under pressure to be pumped into those journals, however; it's not like an old hot box with a simple oiling pad
@@herzogsbuick No kidding. I guess the 30 plus years i spent working in an automotive engine facility rebuilding machinery including precision rotating assemblies didn't teach me a thing
It's all about reducing surface area contact. A roller bearing contacts the surface along one line of the bearing at a time. A ball bearing contacts the surface one point at a time. Add in grease to further restrict surface area contact and you have reduced the contact to a minimum.
It's been claimed that because of the Niagara's lightweight, two people: most likely grown men, were able to push both the locomotive and its centipede tender. You look at these things and think: "There's no way someone could push that big beast" but apparently it was possible back then.
@@AdmiralColdhead Using aluminum wherever possible definitely helped in that regard, but the bearings and careful balancing of the motion made them that much more of a middle finger to friction
yea take out the pistons and the internal valve gear the mechanical pumps and so on it looks good like building a paper 40 ton tank looks good 4 men pick it up
@@AdmiralColdheadAs a Physics teacher, let me explain a few things. The rails need to be absolutely level as the slightest incline will have a vertical force component of high value, way beyond human exertion.As the loco is in a perfect level postion the only resistive force is in the horizontal direction. As these loco use amazing anti-friction bearings the minimal contact surfaces of the balls and rods in the bearings make it possible to move such weights. Also, they incorporate lubricants into the bearing which reduces further adhesive wear. I researched wear as my thesis. So bearings keep surface contact to a minimal, and the grease or oil makes sliding much easier, so a heavy object can be move, only on flat ground. The slightest vertical angle of movement introduces gravity affect and easily exceeds human strength.
The announcer is so proud of himself for knowing the slang used by teenagers ('swell'). Yet his mastery of nomenclature falls short of 'tribology' or 'metrology' which were salient to the subject matter.
Railroads weren't initially interested in roller bearings. Timken had to actually buy a new steam locomotive and outfit it with bearings because no RR would retrofit one to try out roller bearings. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wmyVYj2hJoI.htmlsi=tomFpSFU22ZStU8H
I was thinking the same thing. Even if the wheels are free rolling there is still friction from the piston in the cylinder and the packing on the piston rod. The rest of the valve linkage may or may not roller bearings in it.
Oil and grease. There's oil ont he piston carried on the piston rings, you can sometimes smell it when stood near a steam locomotive. All the bearing surfaces will be coated with oil or grease whatever the bearing type. Roller bearings reduce friction but they still need a little oil or grease to easy the way.
It might be so that the rails had a little of an incline so that the weight of the locomotive helped a bit to overcome the various frictions inside the engine so the pulling by the 5 dames in party shoes was easier.
@@dipling.pitzler7650 just watched an episode of Train Truckers (UK TV series about the people who move trains around the UK by road (reason is it's cheaper to go by road - I know, but that'show we do thing in this country)) and watch a handful of men (about four men) push a 99ton diesel-electric locomotive the last few feet off the trailer after gravity could do no more. The Deltic locomotive had got to the point were the very slight slope of the siding was just too much for the gravity assisted unloading to overcome. So their may have been a little slope assistance.
@@h8GW actually it's American industry Wall street moved mfg to Ccp China slave labor factory prisons for more profits. Now only Chinese take out food is made in America.. And if you ever actually designed built repaired machinery you would understand how bad Chinese metal is .. kid
I'm not sure. The announcer died in December 1952. They don't mention the war... Wikipedia says this series of trains were built in '45-'46, so that's my best guess right there.
In the UK such wagons were in use until the 1980s, but these wagons had low speed limits. Typically they weren't fitted with automatic brakes and were limited to 25mph.
The reason for eliminating plain bearings on interchange cars had little to do with "roller freight" efficiency -- above about 3mph a good hydrodynamic plain bearing is just as effective; in fact, very few IC engines use rollers for critically-loaded parts like crank and big-end bearings. The switch was made for maintenance and reliability: any concerns with rolling wear were constrained to the bearing, and they could be grease-lubricated (as in AP bearings under the M-947 standard) to run longer than the lifetime of the steel wheels themselves.
I don’t see why they would build up heat, as there is not the friction source. But then consider the massive amount of energy required to make this technology possible, and do an efficiency analysis when compared with a diesel-electric train that uses conventional bearings.
Locomotives themselves aren't that efficient. The statistic you're paraphrasing is actually _payload ton_ miles per gallon, which can reach such high numbers because of the enormous loads a freight train can haul and the low rolling resistance of steel wheels. I mean, it's not like the railroads have exclusive access to -magical- premium bearings that semi trucks do not have.
