I feel such gratitude, that two of the biggest science and engineering channels on UA-cam take so much interest in Rail! Thanks Derek, thanks Gradey for the awesome work you do!
As a train driver this was absolutely fascinating. Really gives me an appreciation for what the engineers do through the night when I clock off. Great video.
@@e.e.4695 How are these things mutually exclusive? I hate to break it to you but public services are provided by actual people doing their actual jobs. Just because _some_ peoples' jobs is to market cryptocurrencies or to invent the 3,255th dating app (or any other job that makes money but doesn't provide any worth to society) doesn't mean this person's job isn't, per definition, a public service. I'm grateful for anyone driving a train or maintaining my water supply grid rather than being a real estate agent or an Instagram influencer.
I've been working as a metallurgist in rail manufacturing, welding, and failure analysis around the world for 40 years and this is far and away the best explanation of the thermite welding process that I have ever seen.
Can I ask why "normal" hand welding does not work for rail? (or at least worse than thermite) It would seem (at first glance) that you could also shave down any excess material from the weld, like they already did here. (if I Googled correctly, I suspect FCAW would be needed/easiest for rail tracks?) Would be interested to learn why this isn't the standard :)
@@MrNicoJacnormal welding cannot handle that thickness. That is the short answer. The longer explanation can be deducted from the video where different zones and steel microstructures explained.
I was a foreman on rail thermite crews for about 6 years, and this video is awesome! They need to start showing this video in our training classes. We get the handbook and go over what we should/shouldn't do, but gloss over a lot of 'why' we should/shouldn't do these things. It's also interesting to see the little differences in welding procedures, one I noticed was that after we shear the weld, we put an insulating jacket over the rail to slow the cooling process even further. Another is when first fitting the two halves of the mold to the rail, we hold the molds tight to the rail and grind them against eachother side to side to help get a tight seam. Not as necessary on new rail, but essential on old worn-out tracks. Looking forward to the next video!
Its always useful to educate yourself more on your job, it would just be nice if you got payed for it instead of having to do it in your free time for free.
The box you are talking about I believe is what we call an 'Muffler' used for specific rail grades (don't ask me to quote the rail grade because i've never had to use the muffle box) otherwise the welds break. Rubbing the molds is just good practice for new to new rails. Having the molds nice and tight will stop any 'flashing' forming around the welds. Then there is old to new rail that when welded require 'Spot' Moulds. These molds have extra material on them and need adjusted to fit the specific rail section you are welding. I agree it is interesting watching others do the same process with slight changes!
In Germany "Gleisbauer" (rail builder) is a 3 year vocational education / apprenticeship . Similar to other vocational education "degrees" it's an alternative to a university degree. It's paid and usually about 50% working at a company and 50% at a specialized school teaching you the necessary information and skills to really do the job properly. At the one one gets a paper that proofs that one has the proper qualifications for the specific job. Almost all trades (and also jobs that require university degrees in other countries like for example becoming a nurse) in Germany are done by people who have passed through such a tertiary education path. It's often a true and proper alternative to university degrees. The vocational training/education / apprenticeship system in Germany and some surrounding countries really leads to excellent skilled workers who also understand the deeper science and reasonings behind what they are doing.
3:50 "all experiments were performed under the supervision of professionals with proper safety precautions" all while homeboy is using a torch with the ciggy still lit, God bless.
All welders usually smoke if they want, nobody is going to say no unless a big boss is around. Thats because you weld things way way hotter than a cigarette and they are exposed to way more dangerous gases than a simple cigarette, add the heat around, the heavy and dangerous job and you will see cigarettes like a soda.
I did this for about a year with terrible pay. Back breaking daily work, really makes you appreciate the things that go on behind the scenes to keep a solid infrastructure going.
I spent about 3 weeks taking an old rail line apart, unpaid. It was 'work for the doll' in Australia. The rail was gone but we had to take the big nail things out with huge wedges that look like the claw on a hammer. Had to knock them in with a normal hammer and then, I was on the big 10kg sledge hammer and had to hit down on it to knock the nail out. Sometimes it would shoot into the air like a bullet and everyone would bomb to get away from it. Then, 2 weeks later I got to make big garden beds out of the old sleepers we recovered. Again, unpaid.
Not the worst paid job here in Germany / Western europe and the benefits are good, but given how harsh the work can be still not paid well enough compared to the millions of cushy desk jobs. Not surprised that in lesser developed countries these are the jobs which are truly terrible, but then again its the workers fault for not uniting and fighting for a fair share. One would think people able to do a hard job would be able to fight for decent pay, especially as so many first world economies showed them how and what is possible.
I was waiting for a train many years ago, and they had just upgraded to concrete sleepers. These need continuous welded rail, so they were doing the welds on that night. I showed interest, and they got me down off the platform onto the track, and they let me hold the torch and light one of the ceramic pots off. I’m proud to say that a main line has one of my welds.
@ I’d love to work in the railways but it’s a very competitive field, especially for a train driver or guard, which is what I’d like to be. Also back in the day I would often get cab rides, and sometimes they’d even let me handle the regulator, or the train equivalent of a throttle. Being a kid and in control of about 4,000 horsepower worth of electric motors was amazing. It’s something I’d about kill to experience again.
Derek, your thermite videos part 1 and now part 2 are the most detailled science videos on your channel. I mentioned it on a comment under the first video: i think Goldschmidt did an extraordinary good job on conveying not only an overview of the topic but letting all of us be part of all the technical details of thermite. They took a lot of their working time to not be productive and instead showing you all of the process. I think the videos you created from all that information make a lot of young people getting involved into technical jobs - that is awesome! And now that I hear that you have collected enough material to even create a third video I am really overwhelmed. Great job, Derek! Great job, Goldschmidt! Solche Unternehmen brauchen wir! ❤❤❤❤❤
Thank you so much! It was a lot of work, but it also was a lot of fun. Also we don't get to do this every day. Plus: explaining what you are passionate about, what fascinates you and why is never a waste of time!
@AxelHoeschen Danke.... Ich finde es schön, dass ihr es als keine Zeitverschwendung anseht, und gleichzeitig finde ich es einfach bemerkenswert, dass ihr euch diese Zeit dennoch nehmt, weil in eurer Arbeitszeit kein direkter wirtschaftlicher Mehrwert generiert wird, was vielen Unternehmen aber sehr wichtig ist. Und das, wo ihr nicht mit 1-2 Personen für ein halbstündiges Interview zur Verfügung gestanden habt, sondern mit einem ganzen Team mehrere Tage! Ihr seid einfach super geil, ich feiere euch tierisch ab! 😀 Ein frohes, glückliches und gesundes neues Jahr 2025! 🍀🎉
@@AxelHoeschen I would love to know more about other applications that Thermite could be beneficial (besides railroad steel) ...like fabrication, automotive steel, steel in skyscrapers... This topic could become a much longer series!
@@xtianeskay5166 Wer weiß, vielleicht hat dieses Video ja bei einigen das Interesse geweckt die Ausbildung bei Goldtschmidt Smart Rail Solutions zu machen? Das Video hätte sich dann zumindest aus dieser Perspektive wirtschaftich gelohnt.
I was looking for a cigarette comment. When you see someone working with a cigarette you pretty much know they know what they are doing. And the longer the ash the better they are :D
I don't know why but this video, this series, has felt like what I remember the discovery channel being. That channel has stopped being like that years ago but I'm glad Derek is here to carry the torch on.
I was managing a railways superstructure construction team in my country. There we made 65000 rail welds. Later I moved to Halle city in Germany were the video was made. Nowadays I am doing something else but the video meant a lot to me. I missed all my hardworking colleagues in railways industry. When you ride safely on a train please do not forget those sweaty faces.❤
Just out of curiosity, How many people were on your crew, and how many welds a day could could you get done. I spent a couple years on a welding crew working on Steel gang years ago. There were two crew of 3 people and we were able to do 12-14 welds a day.
@SmokinOak we had 3 methods Enclosed Arc Welding (EAW), Thermit and Flash butt, depending on the project. Flash butt was rental and we supplied ~10-15 worker per car plus forman and 3 technical people and track safety officers etc. Workers were opening and closing the fastening systems and grinding the welds etc. The Thermit was normally used on switches and end points of projects and sometimes per request on the track. The technical crew per trolley was 2. They used to weld 2 joints per 45 min. But each 2 two certified welders had a team of workers depending on the type of work for grinding, fastening opening and closing, cutting, rough alignment etc. Similarly track officers, team leader, inspectors, formen etc was there per few trolley. On average each troley welds 6 - 10 welds per day. For a long time we also used EAW. In EAW we had 1 bigger trolley containing 1 diesel generator and two welding transformer/rectifier. Each troley had 2 meister certified welder, 2 assistants (trainee), 2 fit up experts, 2 motorists for opening and closing the fastening systems, 1 rail cutter (normally was the same os foreman), and 4 simple workers. Each trolley used to make 12 to 20 welds per day. Similarly we had track officers, each 2-6 trolley had a workshop leader, and a team of 2 inspectors.
.....HIERARCHIAL TRUTH IS so POTENT THERE,THOUGH.......LIKE _IF U KNOW SO much,THEN HOW MUCH THE COST OF REPLACING A DAMAGED PART OF RAIL is_ ??? ...LIKE,TRAINS,ESPECIALLY freight ONES,JUST *love* TO MESS UP WITH RAILS,RIGHT????SO,IT'S LIKE okay SOMEWHAT IF WEATHER CONDITIONS ARE JUST RIGHT,BUT if THEYRE NOT???......WAIT FOR GOOD WEATHER??? ....ALSO HOW much WORK TO ACTUALLY replace A PIECE???A lot!!!!!WITH ALL THAT CUTTING ETC ETC ETC ETC ......RIGHT???.......AND STUFF AND STUFF AND STUFF .....COMPARED TO just unscrew,throw away old one,set a new one,screw back.........THAT'S IT!!!!.... .....SO,I'D RATHER TO not STOP ON SCIENTIFIC RESEARCH ABOUT how make a perfect rail joints!!!UNTIL FIND THE PERFECT ONE WHICH WILL BE both silent and low maintainance costs!!!AND EXPERIMENT WITH ANGLED ONES......AND different ANGLES........ ..SORRY FOR THE THING BUT *_i'm against welding rails_*
I worked at Sydney's central station as a structural engineer during a rail shut-down weekend for maintenance. The rail technicians were doing rail welding and were kind enough to explain this whole process and mechanics. They were working under a time constraint so i didnt want to bother them. It was so cool seeing a deeper dive on this and knowing the basics of everything they taught me in a 5mins conversation.
I assume you were also there working with the track technicians during the STAR2 possession in December last year when they were building the tracks to platforms 11-14
@Voyagerthe2nd unfortunately no this was around early last year, from memory those platforms were either the ones they were working on or it was near by because it was the above ground platforms.
was also thinking about Sydney trains and how much flack they take for any downtime. it's hard when there's so many pieces that can go wrong plus things like welding and reduced funding. great stuff for making it work as smoothly as it currently does
The question was "Why don't railroads need expansion joints" the answer was "we mechanically restrain them" and viola, a 27 minute video. Fine, subscribed.
Too bad it ended up being a non-answer, after a 27 minute video. If simply bolting down the rails (which was happening back then too) is enough to prevent expansion and buckling, why were they worried about them in the past?
@@AttilaAsztalos They are welded at a median temperature, at night, so the maximum expansion and contraction are limited to a certain lower value. The welded rails resist deflecting, so they are not prone to deflect into an angle at the joints. Any minor deflection is likely sinusoidal. Steel has a known coefficient of thermal expansion. And environmental data is widely available for all geographic locations now. Not so in the early days. Also, they are not constructing railways as rapidly as they were in the past. So there is no need to work as fast, or throughout the day, as in times past.
@@grindcorgz either you didnt read the comment or are too ignorant to understand it, because the video never once mentioned why people in the past didn't know mechanical restraint was enough to prevent expansion and buckling. Because its true that they did not.
Mechanical engineer here - this video was INCREDIBLE! You meld the theoretical with the real world so well it's just awesome. Showing the actual graph of the test sample and seeing the fracture was soo cool. Took me right back to university days. I wish we had these types of videos to see when I was in university - would have made me even more excited about science than I already was.
@@Wes-x9pMost people who are laborers are smokers. This has been the case for hundreds of years for a reason lol. It helps with stress and numbs the back pain that is always present when working in a labor.
I had a career that spanned over 10 years in rail, most of it in Product Development and R&D. The amount of Engineering and Science that exists in railways will blow your mind. It's a culmination of all fields of Engineering, Electrical/Electronic/Computer, Mechanical/Metallurgy, Civil, Process/Industrial and Chemical. There were also Mathematicians and Physicists. There were so many brilliant minds working together to solve complex problems and keeping trains running smoothly.
We are a small Blacksmith Shop here in Austria but from time to time we make these Wedges für the Austrian Rail Company and in the past also for Goldschmidt Austria and other Companies that do this weldings. Nice to see how these guys work with them
I run a railroad maintenance company in Zimbabwe. with plans to expand into most of the region. Traveling Czech Republic and Germany sometime this year 2nd quarter. I would love to know more about your shop and if we can also become a customer for some consumables you make
In some places (Belgium), we use diagonally cut rails (lengthwise), that will expand one half next to the other. Allows for expansion without risks of derailing or buckling.
Even I was wondering why the technology did not improve from the rt. angle cut to the diagonal cut..... also the two parallel rail welds must be staggered by at least half the length between the two axles(front/rear).
Derek was never a theoretical physicist though (like some of the scientists you can see on the Sixty Symbols channel). He was always grounded in real-world practicality. I think his grad-level background is in methods of teaching and communicating physics, which involves a lot of demos.
As Railroad Technician it makes incredibily happy seeing veritasium at the fields that i operate at a daily basis. Seeing you try all the steps by yourself and get every knowledge behind the things you do is refreshing. I work with a lot of welders and youre right, these guys make it look like its an easy job. The scientific background and the seettrough weld was someting i always wanted to see. The Camera handled that exposure problem very well. Cant wait for the next Part!
They say that lieutenants worry about tactics, colonels strategy, but generals, generals, they worry about logistics. Point being, the older I get, the more I worry, worry about infrastructure. So, I super enjoy vids like this, the science, and art, behind everyday infrastucture upon which we all depend. Thinking about what others do not normally think about: I call that entertainment. And yet deeply educational. Overall, so satisfying. Thank you.
Is this why growing up in the 90s/00s i constantly saw commercials for "TONS AND TONS OF TRAINS! Old trains! New trains! Fast trains, slooow trains! Even trains from around the world!"?
It's all fun and games until you realize those highways need maintenance too, and someone hasn't been paying the bill on filling those potholes. It kind of doesn't matter what type of infrastructure you build if you can't get it maintained.
I get to see them do this every couple of years at night on the tram line right outside my window. Every couple of years they have to replace the tracks from the downhill curve leading to the tram stop, which receives a lot of stress from the trams braking and being in the curve. But I've never seen such a detailed description of exactly what they are doing ever step of the way, and exactly what and all the consequences of deviation are. Absolutely fascinating. Thank you!
My favorite thing about this channel is no matter how big you get, you always remain quality and informative. I see too many creators sell out and start getting sloppy. They do bigger and flashier things as they grow, but loose that informative quality these videos are made to present. Veritasium will always be a favorite channel of mine. ❤
@@emilen2 Oh, then thanks for clearing it up! I often saw glass turning black in experiments in school or in a fireplace. That must have been a other type of glass then?
My grandpa was a german engineer from Essen Germany and has numerous patents regarding these clamps that lock the railroad in place and the whole setup with welded Rails. So a little shout out to my long dead Grandpa Waldemar Bingmann! I miss you!
I've been studying all this christmas to get cerfified as a Railway Traffic Regulator and your video was the best gift possible to start this new year. Thanks and happy new year! 🎉
Worked for the BVG (Berlin metro and transport service) And welding these, one after another, in the underground tunnels was the second sweatiest job I have ever done. Somehow repairing the abrasion was even worse (by welding extra material ontop of the track to repair dents because you had to heat up the entire length of track around the weld to get it to not bend and stick properly. I can still remember the sensation of my shirt becoming part of my back through sweat osmosis.
Hey Derek, would you double check the explanation at 5:42 on why the rails must be angled up? Since the top of the weld gets poured last it will be the last to cool. If the bottom indeed cools first (as depicted in the animation at 21:25 ) it would solidify and shrink, squeezing and deforming the upper more malleable portion together. Then as the top solidifies and shrinks it acts like a hinge around the already solid bottom portion. Thus if it weren't angled up already it would "hinge" below level. The explanation "since there's more metal at the top" makes it sound like if the weld surfaces were parallel there would be no distortion because the same amount of metal is everywhere and the shrink would be perfectly even.
Yes, I was quite unsatisfied with Derek's explanation as well. "Since there's more metal on top..." Well of course it is thicker on top, you put it there, silly.
Loved the choice in editing where you showed what you were learning to do while simultaneously showing the professionals do it on the field. It gives a great contrast of real world vs controlled environment. Also, @23:00 Rearden Steel would have never broken LOL.
Finally, Derek listened to the hearts of mechanical engineers 😂. Now I realize there are many more opportunities in this field. Thank you, Veritasium team! ❤❤
I used to be a thermite welder for CP. Depending on conditions, you can have sun kinks in the summer and where a joint remains, pull-aparts in the winter. You could go out on a pull apart, and the rail would be open two feet. You'd have to bring in a short rail to make a splice. One thing they didn't have to use here is a rail puller. It's a monstrosity to lug around and put together. On a very small pull-apart, you can use ropes soaked in fuel oil to expand the rail by knocking off the anchors for a distance, placing a long length of rope on both sides of the gap and heating the rail until the gap closes and you can put you angle bars on and re-anchor the rail. I've also been on the rail gang in the winter. We'd have a rail heater with a 1000 gallon LP tank to heat the spiked but un-anchor rail, then we'd have to walk behind the heat pounding on anchors with a sledge hammer, that we referred to as a Monday. It could almost make you hate your life. Oftentimes, if you didn't hit the anchor right, it would fly 20 or 30 feet.
A long time ago I was a railroad worker, and during nights we performed the "neutralisation". First knocking off the anchors for a fair bit, then the welders cut out a calculated length of rail depending on the temperature. Then they pulled the rails together with hydraulic pullers. Then termite welded them. And then we pulled all the anchors back into place.
That’s really interesting! I’ve seen a lot of huge tools left over a long stretch of track wondering why they were left. Later I saw the crew bus and some heavy equipment I did not recognise pass by on the track. This was probably what was going on. BC Canada.
@DrPowerElectronics I've helped peddled ribbon rail before, too. Imagine quarter mile sticks of rail on rail cars. You tie one end of the rail down and then drive the train out from under it. As it threads off the train, it's like a snake. You have to be standing on the high rail, or it would be pretty easy to smash or lose a foot.
Cracked one of my teeth thanks to taking off anchors, they were rust welded on so really had to smash them to get them off, sometimes two hits. Had a stubborn one that didnt come off 1 hit, looked over to see where i needed to hit again and a single rock fell on it as it clicked back into place and launched the rock at me. Split my lip cracked a front tooth and still had 4 km of anchors to take off, my busted lip kept snagging on my broken tooth for the rest of the day till i knocked off and went to the dentist.
@matty101yttam I can imagine how bad that must have been. There were a lot of ways to get hurt. Then there's the possibility of being on the gang in the middle of nowhere. We had motor cars a couple of times to work from. One time, they gave me and another guy a dumpy and radio. We were behind the tie gang, fixing high spikes, bent spikes that were damned near impossible to pull with a claw bar. We were way behind the gang. We had one of those dummies that broke in two to clear the track in case of a train. It was cold and misty out. We sat in the cold ditch and ate our lunch. Thay was in my first few months. I remember how sore my feet were, too, walking on that ballast in the cheap pair of boots I'd bought. Good times, lol.
I knew most of the things mentioned in the video, but I never could quite get over the problem of expansion in summer and contraction in winter. No-one ever explained it to me in such a comprehensive and understandable way. Now I finally understand the physics in toto. Thank you for the insight, and thanks to Goldschmidt for the rare footage! Amazing video!
This was absolutely fabulous. Hats off to everyone on the team who did this. I am a chemist, but, to be honest, not one who has any experience whatsoever in the practical applications of chemistry. I'vI taught the thermite reaction in classes, emphasizing the fact that in this rare instance, we get to use the symbols which indicate elemental iron in the *liquid* state.
That see-through half section was amazing... had to play that frame by frame over and over. Wild how it flows and why it's all shaped like that and trying to analyze it. Really cool seeing how it's done in the field as well as a controlled set up, and the difference between them. Remarkable how professionals develop such a fine technique to do it quickly & perfectly compared to the controlled set up.
Derek, your video output for the last few months has been insane. Although I don’t expect it to continue at this rate, I want to thank you for giving me so much content to enjoy and share with my friends and family. Can’t wait to see what you have for us in 2025!
Having worked as a foreman on rail thermite crews for about six years, I’ve got to say, this video is fantastic! They should seriously consider including it in our training sessions. While we do cover the handbook and go through the dos and don’ts, we often skim over the reasoning behind those guidelines. It’s great to see the detailed breakdown here. I also noticed some interesting variations in procedures-for example, after shearing the weld, we use an insulating jacket to slow down the cooling even more. Another thing we do is grind the mold halves against the rail side-to-side during fitting to ensure a tight seal, especially on older, worn tracks. This video really captures the nuances, and I’m excited to see what’s next!
This was posted by someone else 4 days before you posted this: I was a foreman on rail thermite crews for about 6 years, and this video is awesome! They need to start showing this video in our training classes. We get the handbook and go over what we should/shouldn't do, but gloss over a lot of 'why' we should/shouldn't do these things. It's also interesting to see the little differences in welding procedures, one I noticed was that after we shear the weld, we put an insulating jacket over the rail to slow the cooling process even further. Another is when first fitting the two halves of the mold to the rail, we hold the molds tight to the rail and grind them against eachother side to side to help get a tight seam. Not as necessary on new rail, but essential on old worn-out tracks. Looking forward to the next video! Looks familiar, doesn't it? I have two fingers for you. The first is a 👎, and the second is🖕for being a copycat.
Amazing, cannot wait for part 3 :) I worked in the UK Titanium industry for 40 years, I came across a sort of "thermite" type reaction with Titanium a few times. Titanium has a high affinity for Oxygen and Hydrogen in particular when it is in a finely divided/fine form. So Titanium fines and dust from machining operations can build up on machines like lathes etc. Should you also machine Steel then the fines of Titanium and Steel can mix unless you are very careful to clean the machine down after each different material. A mix of Titanium and Steel fines can spontaneously combust. As the Steel fines rust, the Titanium which has a greater affinity for Oxygen than Iron will pull the Oxygen from the rust, a chemical reaction occurs which raises the temperature until it catches fire. I would guess it is a long slow process to start the reaction, but I came across this a couple of times "in the wild" so to speak where machining swarf and fines from mixed materials were dumped aside and caught fire spontaneuosly. Could be a nice little research project for someone and perhaps a useful commercial process for something at the end.
That's how most fires that destroy aluminum fab/manufacturing plants start. Fine aluminum dust and random chunks of iron that has rusted. Eventually, the right ratio of FeO+Al occurs, and it starts getting hot
@@mmorris2830 Ah yes, I am sure lots of such things happen. None of our "experts" aware of the Titanium and Rusty Steel turnings reactions, came as a bit of a shock, though the spontaneous combustion of Titanium Grinding fines, even when wet was a well known thing and resulted in having to store the stuff in 45 gallon drums under water prior to regular disposals.
I love how you've levelled up both the quantity and quality of videos recently. It could easily have suffered with expanded team and new hosts etc. but if anything the content just keeps getting better, longer and more frequent. In a world of so much sensationalised dumbed-down documentary content, thanks for your dedication to high quality science communication!
Awesome video and have just subscribed. A big shoutout to all the rail maintenance crews and companies such as Goldschmidt around the world that keep our trains and rails safe, thank you! We take a such matters for granted and thanks again.
I have much respect for the guys doing the field work at night over and over again. This is a hard job physically and the hours put you slightly of set to the rest of working people around you , making socializing more difficult also. 💪
Its not that hard at all... and they get paid very well here in Germany. Its more like a dumb and boring job... but there is way more to Oberbauschweißen than SKV-Welding. Thermit is just the starting point as an Oberbauschweißer.
@@wtfdude1830I think it's really not that exciting anymore after you done it a few times. It's a repetitive work, that's why you see them smoking while doing it. Physically hard, but mentally must be really boring.
Seeing you do a tensile test as a welder was very neat! And they ARE correct. In many cases when we do tensile tests, a perfect weld would break on either SIDE of the weld, not in the middle of the weld. Because the weld itself, in many cases is ALWAYS stronger than the base material. Which is why we add filler metals and the like back in. But even if you didnt add filler metals, the weld should still keep the properties OF the base metal, and will only break in the Heat Affected Zone, which is why it's important to keep this zone small (especially when doing TIG welds). The smaller the zone, the less chance of failure down the line due to stresses.
Thermite Welder from the UK here! Very cool and informative, enjoyable to see the slight differences in the process they do over in Germany. Usually we just leave the Risers (the excess metal that is left behind after trimming) on the weld then knock them off once its cooled down. Personally I don't see too much of a time save in doing pre grinding as you are having to wait for the rail to cool down regardless. Plus the additional risk of potentially over grinding the rail and dipping the weld if you aren't careful!
Pro's use short, stubby cigarette holders. You can point it at the side, away from your nose and you can plug the end with your tongue so you can breathe without constantly drawing smoke. When i smoked and worked, that little stubby holder was god send, you can easily keep working without eyes and nose stinging, and since pro's also roll their own cigarrette's, they will extinguish on their own. So, if you work and smoke, get one of those stubby holders.
Great to see the ingenuity of some engineer 100 years ago still has such a huge and lasting impact today. Shoutout to the Elektro Thermit team to give access and such insights into their world! Grüße nach Halle
Great video! I work with Thermite every day for a completely different application than railroads, but still, your videos are both entertaining and educational. The Goldschmidt crew has an incredible history and knowledge of this topic, making it a great choice for this series! Cant wait for the next episode! 😁
Its not only that, but afaik every welded rail cant go in a perfectly straight line. Since its constantly curving left and right the railway can expand by pushing itself into slightly more of a S pattern, while in winter it can slightly straighten itself out.
Some of these comments are beautiful. I really hope that the whole Veritasium team continues to be extremely proud of the work they do. As an educator, I am inspired by what you do. The quality of the explanations and visual demonstrations in all your videos are simply amazing.
I grew up in Chicago and had railroad tracks 1 block away that all the neighborhood kids played around. The tracks are elevated above the road along the back of factories. I always seen the tracks joined together with bolts and they would have braided wire connecting them as well. Never ever seen welded tracks in person.
Absolutely fascinating! The combination of chemistry and engineering in thermite welding is mind-blowing. Seeing how science is applied to something as crucial as railway construction really makes you appreciate the innovation behind our everyday infrastructure. Thanks for making this process so accessible and engaging.
I worked on the Eglinton LRT in Toronto back in 2021 and saw a crew of people doing this. It looked neat but I did not really get to talk to them. This video explains a lot, really well made and detailed.
Love a video that combines the concepts of microstructure in steel and Stefan-Boltzmann law. Would have loved it even more if you let the people know about the pearlier structure of the steel that was slowly cooled
Now that is a really incredible process related to Thermite and rail construction! It looks like Veritasium will soon have 17 Million subscribers! 👍👍💥💥
Watching this on a 4k HDR1000 48" OLED on a desk was amazing, thanks for making all the effort required to shoot in 4K, and thanks in general for the content you make!
1:46 this gave me a Vietnam Flashback that I didn't realise I had! The Yorkshire Three Peaks Challenge was possibly the most horrendous 9 hour ordeal of my life.
Thank you for giving credit to Grady in your video instead of just in the description. Your video was clearly inspired by his, so he deserves the credit in a place most people will see (and most people don't read video descriptions).
happy new year sir , i am 15 year old and love your content sir , keep uploding more about mathematics the visual explanation , science , how everything works , thank you
Not long ago here in Singapore a broken-down MRT metro train with a damaged bogie badly damaged a long stretch of track as it was being taken out of service and back to the depot. The damage included breaks to the running rails, damaged or destroyed trackside equipment, and damage to the power-supplying third rail; it took nearly a week before repairs were completed to a degree where passenger-service trains were able to run again over the affected stretch. Our metro system uses continuously-welded running rails as well, and seeing how tedious and involved the process to weld the rails together is here gave me a better understanding and appreciation of why it took the railway engineers so much time to repair the damaged tracks - having to cut out the broken rails, splice in the new rails, aligning them properly, welding them together to the required strength, and grinding them down to make them smooth, and all that was just for the running rails (they had to repair or replace all of the other damaged trackside equipment and third rail as well, which is probably its own involved process I’m sure). Given the temperature requirements they probably couldn’t do the rail-welding procedure during the day, and they almost certainly couldn’t do it during rainy weather as well because of potential water contamination, which is made worse by our temperamental weather especially around the time when that whole incident occurred.
BTW: the signature sound is still there, just less often: every time you cross a railroad-switch. Great video, makes you realize how precise and hard these orange-collar workers work and let's you appreciate their work more therefore!
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Happy new year derek!
@@iamnotdarshan happy new year!!!
How can ur comment posted 1 hour ago while the vids itself came out 7 min. Ago...
Wait bro's the poster..
HI DEREK!!! Love your content, I've been following you as long as I can remember at this point. Much love!
I haven't showered since last year
Thanks for the shoutout. The cross-section demo was awesome!
I feel such gratitude, that two of the biggest science and engineering channels on UA-cam take so much interest in Rail! Thanks Derek, thanks Gradey for the awesome work you do!
Hi, Im Franky. And this is practical.... learning from the the best of both worlds!
The first video I saw of yours was about welding railroads, reminded me of my late grandpa who loved trains and drove for Amtrak
Love your channel!
Was hoping this was a collab…
As a train driver this was absolutely fascinating. Really gives me an appreciation for what the engineers do through the night when I clock off. Great video.
@@nikc1313 thank you for your service!
@@danielbum912 What service? It's a job, he makes money, that's it.
@@e.e.4695so anyone who is compensated is not providing a service? :facepalm:
@@e.e.4695 Money is used for the purchase of goods and services. Transportation is a service, so a train driver provides a service.
@@e.e.4695 How are these things mutually exclusive? I hate to break it to you but public services are provided by actual people doing their actual jobs. Just because _some_ peoples' jobs is to market cryptocurrencies or to invent the 3,255th dating app (or any other job that makes money but doesn't provide any worth to society) doesn't mean this person's job isn't, per definition, a public service. I'm grateful for anyone driving a train or maintaining my water supply grid rather than being a real estate agent or an Instagram influencer.
I've been working as a metallurgist in rail manufacturing, welding, and failure analysis around the world for 40 years and this is far and away the best explanation of the thermite welding process that I have ever seen.
Thanks for all your hard work!
The techs at Goldschmitt are verry proud of that their making. This is German engenering at its best.
Can I ask why "normal" hand welding does not work for rail?
(or at least worse than thermite)
It would seem (at first glance) that you could also shave down any excess material from the weld, like they already did here.
(if I Googled correctly, I suspect FCAW would be needed/easiest for rail tracks?)
Would be interested to learn why this isn't the standard :)
@@MrNicoJacnormal welding cannot handle that thickness. That is the short answer. The longer explanation can be deducted from the video where different zones and steel microstructures explained.
@@MrNicoJacwire feed welding is used extensively. Thermite is just the focus the narrative for this video.
I was a foreman on rail thermite crews for about 6 years, and this video is awesome! They need to start showing this video in our training classes. We get the handbook and go over what we should/shouldn't do, but gloss over a lot of 'why' we should/shouldn't do these things. It's also interesting to see the little differences in welding procedures, one I noticed was that after we shear the weld, we put an insulating jacket over the rail to slow the cooling process even further. Another is when first fitting the two halves of the mold to the rail, we hold the molds tight to the rail and grind them against eachother side to side to help get a tight seam. Not as necessary on new rail, but essential on old worn-out tracks. Looking forward to the next video!
The best comment, I think.
Its always useful to educate yourself more on your job, it would just be nice if you got payed for it instead of having to do it in your free time for free.
The box you are talking about I believe is what we call an 'Muffler' used for specific rail grades (don't ask me to quote the rail grade because i've never had to use the muffle box) otherwise the welds break. Rubbing the molds is just good practice for new to new rails. Having the molds nice and tight will stop any 'flashing' forming around the welds. Then there is old to new rail that when welded require 'Spot' Moulds. These molds have extra material on them and need adjusted to fit the specific rail section you are welding. I agree it is interesting watching others do the same process with slight changes!
In Germany "Gleisbauer" (rail builder) is a 3 year vocational education / apprenticeship .
Similar to other vocational education "degrees" it's an alternative to a university degree. It's paid and usually about 50% working at a company and 50% at a specialized school teaching you the necessary information and skills to really do the job properly. At the one one gets a paper that proofs that one has the proper qualifications for the specific job.
Almost all trades (and also jobs that require university degrees in other countries like for example becoming a nurse) in Germany are done by people who have passed through such a tertiary education path. It's often a true and proper alternative to university degrees.
The vocational training/education / apprenticeship system in Germany and some surrounding countries really leads to excellent skilled workers who also understand the deeper science and reasonings behind what they are doing.
I also learned recently thermite is used to form continuous copper ground bonds at broadcast tower sites! It's cool to see it in action.
And to cook Hot Dogs! (I couldn't resist) Happy New Year Jeff
@@mrfoodaramahappy new year! Hot dogs, bratwurst, you name it, I'll make it talk!
@@JeffGeerling Even AI XD
Yes, I used to do that at cell phone tower sites. We called it CAD welding.
@@JeffGeerling Happy new year, Jeff. Wasn't expecting to see you here.
3:50 "all experiments were performed under the supervision of professionals with proper safety precautions" all while homeboy is using a torch with the ciggy still lit, God bless.
jordan?
The cigarette shows he's a pro
All welders usually smoke if they want, nobody is going to say no unless a big boss is around.
Thats because you weld things way way hotter than a cigarette and they are exposed to way more dangerous gases than a simple cigarette, add the heat around, the heavy and dangerous job and you will see cigarettes like a soda.
Smoking and metal fabrication go together like peas and carrots. It's in the bible I think. 😂
...and no glasses whilst grinding....
I did this for about a year with terrible pay. Back breaking daily work, really makes you appreciate the things that go on behind the scenes to keep a solid infrastructure going.
Thank you for your work!
I spent about 3 weeks taking an old rail line apart, unpaid. It was 'work for the doll' in Australia. The rail was gone but we had to take the big nail things out with huge wedges that look like the claw on a hammer. Had to knock them in with a normal hammer and then, I was on the big 10kg sledge hammer and had to hit down on it to knock the nail out. Sometimes it would shoot into the air like a bullet and everyone would bomb to get away from it.
Then, 2 weeks later I got to make big garden beds out of the old sleepers we recovered. Again, unpaid.
Makes you appreciate men!
@@BabyMakR unpaid loose term.
Not the worst paid job here in Germany / Western europe and the benefits are good, but given how harsh the work can be still not paid well enough compared to the millions of cushy desk jobs.
Not surprised that in lesser developed countries these are the jobs which are truly terrible, but then again its the workers fault for not uniting and fighting for a fair share. One would think people able to do a hard job would be able to fight for decent pay, especially as so many first world economies showed them how and what is possible.
I was waiting for a train many years ago, and they had just upgraded to concrete sleepers. These need continuous welded rail, so they were doing the welds on that night. I showed interest, and they got me down off the platform onto the track, and they let me hold the torch and light one of the ceramic pots off. I’m proud to say that a main line has one of my welds.
I just got to see all the stuff sitting still from an overpass bridge. Jealous. 🙃
@ I’d love to work in the railways but it’s a very competitive field, especially for a train driver or guard, which is what I’d like to be. Also back in the day I would often get cab rides, and sometimes they’d even let me handle the regulator, or the train equivalent of a throttle. Being a kid and in control of about 4,000 horsepower worth of electric motors was amazing. It’s something I’d about kill to experience again.
the correct way to start a new year!! Thank you Veritasium
A video on how thermite turned the WTC into rubble might have been better.
Dull
Ok
When you heard "rail" and "line" amidst the new years cheering, I don't think this video was what your friends were calling for.
Derek, your thermite videos part 1 and now part 2 are the most detailled science videos on your channel. I mentioned it on a comment under the first video: i think Goldschmidt did an extraordinary good job on conveying not only an overview of the topic but letting all of us be part of all the technical details of thermite. They took a lot of their working time to not be productive and instead showing you all of the process. I think the videos you created from all that information make a lot of young people getting involved into technical jobs - that is awesome! And now that I hear that you have collected enough material to even create a third video I am really overwhelmed. Great job, Derek! Great job, Goldschmidt! Solche Unternehmen brauchen wir! ❤❤❤❤❤
Thank you so much! It was a lot of work, but it also was a lot of fun. Also we don't get to do this every day. Plus: explaining what you are passionate about, what fascinates you and why is never a waste of time!
@AxelHoeschen Danke.... Ich finde es schön, dass ihr es als keine Zeitverschwendung anseht, und gleichzeitig finde ich es einfach bemerkenswert, dass ihr euch diese Zeit dennoch nehmt, weil in eurer Arbeitszeit kein direkter wirtschaftlicher Mehrwert generiert wird, was vielen Unternehmen aber sehr wichtig ist. Und das, wo ihr nicht mit 1-2 Personen für ein halbstündiges Interview zur Verfügung gestanden habt, sondern mit einem ganzen Team mehrere Tage! Ihr seid einfach super geil, ich feiere euch tierisch ab! 😀 Ein frohes, glückliches und gesundes neues Jahr 2025! 🍀🎉
grateful
@@AxelHoeschen I would love to know more about other applications that Thermite could be beneficial (besides railroad steel) ...like fabrication, automotive steel, steel in skyscrapers... This topic could become a much longer series!
@@xtianeskay5166 Wer weiß, vielleicht hat dieses Video ja bei einigen das Interesse geweckt die Ausbildung bei Goldtschmidt Smart Rail Solutions zu machen? Das Video hätte sich dann zumindest aus dieser Perspektive wirtschaftich gelohnt.
7:45 that ash on the cigarette is amazing! Artist at work.
How does that not fall off! Wow
I don't smoke, but how in the world does that not fall off? That dude must be dragging hard on that thing.
You can tell he isn't going to put his hands on it again until that rail is set up tight.
I was looking for a cigarette comment. When you see someone working with a cigarette you pretty much know they know what they are doing. And the longer the ash the better they are :D
I have no clue how people can keep their eyes open with the cig smoke in their eyes.
I don't know why but this video, this series, has felt like what I remember the discovery channel being. That channel has stopped being like that years ago but I'm glad Derek is here to carry the torch on.
I was managing a railways superstructure construction team in my country. There we made 65000 rail welds. Later I moved to Halle city in Germany were the video was made. Nowadays I am doing something else but the video meant a lot to me. I missed all my hardworking colleagues in railways industry. When you ride safely on a train please do not forget those sweaty faces.❤
Just out of curiosity, How many people were on your crew, and how many welds a day could could you get done.
I spent a couple years on a welding crew working on Steel gang years ago. There were two crew of 3 people and we were able to do 12-14 welds a day.
@SmokinOak we had 3 methods Enclosed Arc Welding (EAW), Thermit and Flash butt, depending on the project. Flash butt was rental and we supplied ~10-15 worker per car plus forman and 3 technical people and track safety officers etc. Workers were opening and closing the fastening systems and grinding the welds etc.
The Thermit was normally used on switches and end points of projects and sometimes per request on the track. The technical crew per trolley was 2. They used to weld 2 joints per 45 min. But each 2 two certified welders had a team of workers depending on the type of work for grinding, fastening opening and closing, cutting, rough alignment etc. Similarly track officers, team leader, inspectors, formen etc was there per few trolley. On average each troley welds 6 - 10 welds per day.
For a long time we also used EAW. In EAW we had 1 bigger trolley containing 1 diesel generator and two welding transformer/rectifier. Each troley had 2 meister certified welder, 2 assistants (trainee), 2 fit up experts, 2 motorists for opening and closing the fastening systems, 1 rail cutter (normally was the same os foreman), and 4 simple workers. Each trolley used to make 12 to 20 welds per day. Similarly we had track officers, each 2-6 trolley had a workshop leader, and a team of 2 inspectors.
.....HIERARCHIAL TRUTH IS so POTENT THERE,THOUGH.......LIKE _IF U KNOW SO much,THEN HOW MUCH THE COST OF REPLACING A DAMAGED PART OF RAIL is_ ???
...LIKE,TRAINS,ESPECIALLY freight ONES,JUST *love* TO MESS UP WITH RAILS,RIGHT????SO,IT'S LIKE okay SOMEWHAT IF WEATHER CONDITIONS ARE JUST RIGHT,BUT if THEYRE NOT???......WAIT FOR GOOD WEATHER???
....ALSO HOW much WORK TO ACTUALLY replace A PIECE???A lot!!!!!WITH ALL THAT CUTTING ETC ETC ETC ETC ......RIGHT???.......AND STUFF AND STUFF AND STUFF
.....COMPARED TO just unscrew,throw away old one,set a new one,screw back.........THAT'S IT!!!!....
.....SO,I'D RATHER TO not STOP ON SCIENTIFIC RESEARCH ABOUT how make a perfect rail joints!!!UNTIL FIND THE PERFECT ONE WHICH WILL BE both silent and low maintainance costs!!!AND EXPERIMENT WITH ANGLED ONES......AND different ANGLES........
..SORRY FOR THE THING BUT *_i'm against welding rails_*
I worked at Sydney's central station as a structural engineer during a rail shut-down weekend for maintenance. The rail technicians were doing rail welding and were kind enough to explain this whole process and mechanics. They were working under a time constraint so i didnt want to bother them. It was so cool seeing a deeper dive on this and knowing the basics of everything they taught me in a 5mins conversation.
I assume you were also there working with the track technicians during the STAR2 possession in December last year when they were building the tracks to platforms 11-14
@Voyagerthe2nd unfortunately no this was around early last year, from memory those platforms were either the ones they were working on or it was near by because it was the above ground platforms.
I was looking for someone to write this, i always wondered what they do every public holidays to repair the line in Sydney.
was also thinking about Sydney trains and how much flack they take for any downtime. it's hard when there's so many pieces that can go wrong plus things like welding and reduced funding. great stuff for making it work as smoothly as it currently does
As a welder, I thank you for your appreciation of what we do.
The question was "Why don't railroads need expansion joints" the answer was "we mechanically restrain them" and viola, a 27 minute video. Fine, subscribed.
Too bad it ended up being a non-answer, after a 27 minute video. If simply bolting down the rails (which was happening back then too) is enough to prevent expansion and buckling, why were they worried about them in the past?
@@AttilaAsztalos They are welded at a median temperature, at night, so the maximum expansion and contraction are limited to a certain lower value.
The welded rails resist deflecting, so they are not prone to deflect into an angle at the joints. Any minor deflection is likely sinusoidal.
Steel has a known coefficient of thermal expansion. And environmental data is widely available for all geographic locations now. Not so in the early days.
Also, they are not constructing railways as rapidly as they were in the past. So there is no need to work as fast, or throughout the day, as in times past.
@@AttilaAsztalos either you didnt watch the video or you didnt understand the answer because he explained it perfectly lol
@@Triple_J.1thank you, I also felt the title wasn’t fully answered in the video. Did learn a lot about material science and welding at least.
@@grindcorgz either you didnt read the comment or are too ignorant to understand it, because the video never once mentioned why people in the past didn't know mechanical restraint was enough to prevent expansion and buckling. Because its true that they did not.
Mechanical engineer here - this video was INCREDIBLE! You meld the theoretical with the real world so well it's just awesome. Showing the actual graph of the test sample and seeing the fracture was soo cool. Took me right back to university days. I wish we had these types of videos to see when I was in university - would have made me even more excited about science than I already was.
7:50 how to spot a professional: it’s the guy chain smoking while working with both hands
My exact toughts!
Word
Dat ash 😂
Or an addicted Fool.
@@Wes-x9pMost people who are laborers are smokers. This has been the case for hundreds of years for a reason lol. It helps with stress and numbs the back pain that is always present when working in a labor.
I had a career that spanned over 10 years in rail, most of it in Product Development and R&D. The amount of Engineering and Science that exists in railways will blow your mind. It's a culmination of all fields of Engineering, Electrical/Electronic/Computer, Mechanical/Metallurgy, Civil, Process/Industrial and Chemical. There were also Mathematicians and Physicists. There were so many brilliant minds working together to solve complex problems and keeping trains running smoothly.
Geology too.
Wow, thank you for your work!
O’ playing you
We are a small Blacksmith Shop here in Austria but from time to time we make these Wedges für the Austrian Rail Company and in the past also for Goldschmidt Austria and other Companies that do this weldings. Nice to see how these guys work with them
I run a railroad maintenance company in Zimbabwe. with plans to expand into most of the region. Traveling Czech Republic and Germany sometime this year 2nd quarter. I would love to know more about your shop and if we can also become a customer for some consumables you make
In some places (Belgium), we use diagonally cut rails (lengthwise), that will expand one half next to the other.
Allows for expansion without risks of derailing or buckling.
Even I was wondering why the technology did not improve from the rt. angle cut to the diagonal cut.....
also the two parallel rail welds must be staggered by at least half the length between the two axles(front/rear).
HUUUGE respect for the people that do this every day, I don't think I need to explain why.
Man who started out as a theoretical physicist on youtube turned into promoting something learned at trade school :) respect man.
In North America, railroads and contractors teach in rail yards and on track.
Science and engeneering are linked strongly, one is reaserch twods anything and everything the other is aplication for findings useful.
Derek was never a theoretical physicist though (like some of the scientists you can see on the Sixty Symbols channel). He was always grounded in real-world practicality. I think his grad-level background is in methods of teaching and communicating physics, which involves a lot of demos.
@@Octoschizare his bachelor is on engineering physics, his later Phd is on science communication
Smarter Everyday ;)
As Railroad Technician it makes incredibily happy seeing veritasium at the fields that i operate at a daily basis.
Seeing you try all the steps by yourself and get every knowledge behind the things you do is refreshing.
I work with a lot of welders and youre right, these guys make it look like its an easy job.
The scientific background and the seettrough weld was someting i always wanted to see. The Camera handled that exposure problem very well.
Cant wait for the next Part!
As a Metallurgist it was really fascinating to watch. I really appreciate the effort put up by the Veritasium TEAM. Kudos to you guys 🙌
They say that lieutenants worry about tactics, colonels strategy, but generals, generals, they worry about logistics. Point being, the older I get, the more I worry, worry about infrastructure. So, I super enjoy vids like this, the science, and art, behind everyday infrastucture upon which we all depend. Thinking about what others do not normally think about: I call that entertainment. And yet deeply educational. Overall, so satisfying. Thank you.
Is this why growing up in the 90s/00s i constantly saw commercials for "TONS AND TONS OF TRAINS! Old trains! New trains! Fast trains, slooow trains! Even trains from around the world!"?
@@A.Filthy.Casual you just unlocked a memory in me!
Going by your username I'm guessing you were born in 1381. That's a long time to worry about infrastructure. Also, can I be a vampire too? 😂
I don't worry about infrastructure. If it gets too bad you can always add another lane to a highway. Simple, efficient, inexpensive. 🌈🇺🇸
It's all fun and games until you realize those highways need maintenance too, and someone hasn't been paying the bill on filling those potholes.
It kind of doesn't matter what type of infrastructure you build if you can't get it maintained.
happy new year🎉
Happy new year 🎊🎊🎊🎊
evil new year 😈
Happy new year!
happy new year 🎉
Happy new year!
I get to see them do this every couple of years at night on the tram line right outside my window. Every couple of years they have to replace the tracks from the downhill curve leading to the tram stop, which receives a lot of stress from the trams braking and being in the curve. But I've never seen such a detailed description of exactly what they are doing ever step of the way, and exactly what and all the consequences of deviation are. Absolutely fascinating. Thank you!
My favorite thing about this channel is no matter how big you get, you always remain quality and informative. I see too many creators sell out and start getting sloppy. They do bigger and flashier things as they grow, but loose that informative quality these videos are made to present. Veritasium will always be a favorite channel of mine. ❤
The footage of the preheating with glass is fantastic.
I am amazed they found glass that can handle the temperature and temperature gradient!
@@jovetjFor real. Normal glass would probably have turned black really quick.
@That_Student_ It would have cracked and/or melted. No discolouring though.
They might be using fused quartz or other exotic high temp glass.
@@emilen2 Oh, then thanks for clearing it up! I often saw glass turning black in experiments in school or in a fireplace. That must have been a other type of glass then?
@That_Student_ do you know the name of the glass?
My grandpa was a german engineer from Essen Germany and has numerous patents regarding these clamps that lock the railroad in place and the whole setup with welded Rails.
So a little shout out to my long dead Grandpa Waldemar Bingmann! I miss you!
schon 1939 promoviert, glaub er hat Jahrzehnte deutsche Eisenbahngeschichte geprägt :)
One of humanities heroes! May he rest in glory..
I've been studying all this christmas to get cerfified as a Railway Traffic Regulator and your video was the best gift possible to start this new year. Thanks and happy new year! 🎉
Man I just have to say how much I enjoy your videos. Thank you for taking the time and work to put these together.
Worked for the BVG (Berlin metro and transport service)
And welding these, one after another, in the underground tunnels was the second sweatiest job I have ever done.
Somehow repairing the abrasion was even worse (by welding extra material ontop of the track to repair dents because you had to heat up the entire length of track around the weld to get it to not bend and stick properly.
I can still remember the sensation of my shirt becoming part of my back through sweat osmosis.
If welding in a tunnel only ranked second, what was the sweatiest job you've ever done?? 😅
What was the first??
@@emilyrln Barkeeper at Berghain? :P
Danke, dass du das dennoch gemacht hast. Infrastruktur ist fast so wichtig, wie die Facharbeiter, die sie am laufen halten.
My stepdad works there too :D as an Electric/welding engineer. really interesting stuff
Hey Derek, would you double check the explanation at 5:42 on why the rails must be angled up? Since the top of the weld gets poured last it will be the last to cool. If the bottom indeed cools first (as depicted in the animation at 21:25 ) it would solidify and shrink, squeezing and deforming the upper more malleable portion together. Then as the top solidifies and shrinks it acts like a hinge around the already solid bottom portion. Thus if it weren't angled up already it would "hinge" below level. The explanation "since there's more metal at the top" makes it sound like if the weld surfaces were parallel there would be no distortion because the same amount of metal is everywhere and the shrink would be perfectly even.
Yes, I was quite unsatisfied with Derek's explanation as well.
"Since there's more metal on top..."
Well of course it is thicker on top, you put it there, silly.
@@XxZeldaxXXxLinkxX maybe he means on the rail, since its an I-beam, but then that would also be true on the bottom so idk
Sounded like an explanation from chat gpt to me
I also didn’t understand this part. If the rails weren’t angled at all, wouldn’t the even amount of metal from top to bottom pull them in evenly?
@@XxZeldaxXXxLinkxX `yep! .... more metal on the top ... ergo greater mass on the top than t/o rest of the sectioned rail.
Loved the choice in editing where you showed what you were learning to do while simultaneously showing the professionals do it on the field. It gives a great contrast of real world vs controlled environment. Also, @23:00 Rearden Steel would have never broken LOL.
Finally, Derek listened to the hearts of mechanical engineers 😂. Now I realize there are many more opportunities in this field. Thank you, Veritasium team! ❤❤
I love these dirty jobs style videos. It shows how complex seemingly simple jobs are and how much skill you need.
Why is it a dirty job? Are they working on the sewage system?
@@mernokimuvek I am refering to the old program of Mike Rowe where he takes on dirty, difficult or dangerous jobs.
I used to be a thermite welder for CP. Depending on conditions, you can have sun kinks in the summer and where a joint remains, pull-aparts in the winter. You could go out on a pull apart, and the rail would be open two feet. You'd have to bring in a short rail to make a splice. One thing they didn't have to use here is a rail puller. It's a monstrosity to lug around and put together. On a very small pull-apart, you can use ropes soaked in fuel oil to expand the rail by knocking off the anchors for a distance, placing a long length of rope on both sides of the gap and heating the rail until the gap closes and you can put you angle bars on and re-anchor the rail. I've also been on the rail gang in the winter. We'd have a rail heater with a 1000 gallon LP tank to heat the spiked but un-anchor rail, then we'd have to walk behind the heat pounding on anchors with a sledge hammer, that we referred to as a Monday. It could almost make you hate your life. Oftentimes, if you didn't hit the anchor right, it would fly 20 or 30 feet.
A long time ago I was a railroad worker, and during nights we performed the "neutralisation". First knocking off the anchors for a fair bit, then the welders cut out a calculated length of rail depending on the temperature. Then they pulled the rails together with hydraulic pullers. Then termite welded them. And then we pulled all the anchors back into place.
That’s really interesting! I’ve seen a lot of huge tools left over a long stretch of track wondering why they were left. Later I saw the crew bus and some heavy equipment I did not recognise pass by on the track. This was probably what was going on. BC Canada.
@DrPowerElectronics I've helped peddled ribbon rail before, too. Imagine quarter mile sticks of rail on rail cars. You tie one end of the rail down and then drive the train out from under it. As it threads off the train, it's like a snake. You have to be standing on the high rail, or it would be pretty easy to smash or lose a foot.
Cracked one of my teeth thanks to taking off anchors, they were rust welded on so really had to smash them to get them off, sometimes two hits. Had a stubborn one that didnt come off 1 hit, looked over to see where i needed to hit again and a single rock fell on it as it clicked back into place and launched the rock at me. Split my lip cracked a front tooth and still had 4 km of anchors to take off, my busted lip kept snagging on my broken tooth for the rest of the day till i knocked off and went to the dentist.
@matty101yttam I can imagine how bad that must have been. There were a lot of ways to get hurt. Then there's the possibility of being on the gang in the middle of nowhere. We had motor cars a couple of times to work from. One time, they gave me and another guy a dumpy and radio. We were behind the tie gang, fixing high spikes, bent spikes that were damned near impossible to pull with a claw bar. We were way behind the gang. We had one of those dummies that broke in two to clear the track in case of a train. It was cold and misty out. We sat in the cold ditch and ate our lunch. Thay was in my first few months. I remember how sore my feet were, too, walking on that ballast in the cheap pair of boots I'd bought. Good times, lol.
I knew most of the things mentioned in the video, but I never could quite get over the problem of expansion in summer and contraction in winter. No-one ever explained it to me in such a comprehensive and understandable way. Now I finally understand the physics in toto. Thank you for the insight, and thanks to Goldschmidt for the rare footage! Amazing video!
This was absolutely fabulous. Hats off to everyone on the team who did this.
I am a chemist, but, to be honest, not one who has any experience whatsoever in the practical applications of chemistry. I'vI taught the thermite reaction in classes, emphasizing the fact that in this rare instance, we get to use the symbols which indicate elemental iron in the *liquid* state.
As a transit nerd, this is literally and figuratively the most metal thing I've seen.
😂😂❤
Why would u have that as smth ur nerdy for 😂😂
That see-through half section was amazing... had to play that frame by frame over and over. Wild how it flows and why it's all shaped like that and trying to analyze it. Really cool seeing how it's done in the field as well as a controlled set up, and the difference between them. Remarkable how professionals develop such a fine technique to do it quickly & perfectly compared to the controlled set up.
Derek, your video output for the last few months has been insane. Although I don’t expect it to continue at this rate, I want to thank you for giving me so much content to enjoy and share with my friends and family.
Can’t wait to see what you have for us in 2025!
Having worked as a foreman on rail thermite crews for about six years, I’ve got to say, this video is fantastic! They should seriously consider including it in our training sessions. While we do cover the handbook and go through the dos and don’ts, we often skim over the reasoning behind those guidelines. It’s great to see the detailed breakdown here. I also noticed some interesting variations in procedures-for example, after shearing the weld, we use an insulating jacket to slow down the cooling even more. Another thing we do is grind the mold halves against the rail side-to-side during fitting to ensure a tight seal, especially on older, worn tracks. This video really captures the nuances, and I’m excited to see what’s next!
This was posted by someone else 4 days before you posted this:
I was a foreman on rail thermite crews for about 6 years, and this video is awesome! They need to start showing this video in our training classes. We get the handbook and go over what we should/shouldn't do, but gloss over a lot of 'why' we should/shouldn't do these things. It's also interesting to see the little differences in welding procedures, one I noticed was that after we shear the weld, we put an insulating jacket over the rail to slow the cooling process even further. Another is when first fitting the two halves of the mold to the rail, we hold the molds tight to the rail and grind them against eachother side to side to help get a tight seam. Not as necessary on new rail, but essential on old worn-out tracks. Looking forward to the next video!
Looks familiar, doesn't it? I have two fingers for you. The first is a 👎, and the second is🖕for being a copycat.
Amazing, cannot wait for part 3 :)
I worked in the UK Titanium industry for 40 years, I came across a sort of "thermite" type reaction with Titanium a few times. Titanium has a high affinity for Oxygen and Hydrogen in particular when it is in a finely divided/fine form. So Titanium fines and dust from machining operations can build up on machines like lathes etc. Should you also machine Steel then the fines of Titanium and Steel can mix unless you are very careful to clean the machine down after each different material. A mix of Titanium and Steel fines can spontaneously combust. As the Steel fines rust, the Titanium which has a greater affinity for Oxygen than Iron will pull the Oxygen from the rust, a chemical reaction occurs which raises the temperature until it catches fire. I would guess it is a long slow process to start the reaction, but I came across this a couple of times "in the wild" so to speak where machining swarf and fines from mixed materials were dumped aside and caught fire spontaneuosly.
Could be a nice little research project for someone and perhaps a useful commercial process for something at the end.
That's how most fires that destroy aluminum fab/manufacturing plants start. Fine aluminum dust and random chunks of iron that has rusted. Eventually, the right ratio of FeO+Al occurs, and it starts getting hot
@@mmorris2830 Ah yes, I am sure lots of such things happen. None of our "experts" aware of the Titanium and Rusty Steel turnings reactions, came as a bit of a shock, though the spontaneous combustion of Titanium Grinding fines, even when wet was a well known thing and resulted in having to store the stuff in 45 gallon drums under water prior to regular disposals.
I don't think I'd want to be anywhere near a titanium fire.
Its crazy how perfectly accurate everything has to be
This channel has became what Discovery Channel was for me when I was a kid, and I love it.
I love how you've levelled up both the quantity and quality of videos recently. It could easily have suffered with expanded team and new hosts etc. but if anything the content just keeps getting better, longer and more frequent. In a world of so much sensationalised dumbed-down documentary content, thanks for your dedication to high quality science communication!
19:02 "North Korea" Lmao
Haha I love it!
They exist since 1895,
so very likely that they had trade relationships also back then
(before the embargo)
The question was "viewers riding on his welded tracks". No internet, no viewers, so they aren't part of the sample set.
Surely they're not watching Veritasium videos though, as the context implies
I'm 100% sure there's a clickty-clack every few seconds on some of the trains in Bulgaria.🥲
Great to have you folks here in Germany! Have a great new year! 🇩🇪🇺🇸
I love how you reference other videos and give praise to other creators.
The cherry on the top is the link in the description.
Awesome video and have just subscribed. A big shoutout to all the rail maintenance crews and companies such as Goldschmidt around the world that keep our trains and rails safe, thank you! We take a such matters for granted and thanks again.
I have much respect for the guys doing the field work at night over and over again.
This is a hard job physically and the hours put you slightly of set to the rest of working people around you , making socializing more difficult also. 💪
Its not that hard at all... and they get paid very well here in Germany. Its more like a dumb and boring job... but there is way more to Oberbauschweißen than SKV-Welding. Thermit is just the starting point as an Oberbauschweißer.
@@wiLdchiLd2k Then can you do it and post a video about it if you say it's dumb, boring and not hard at all
@@wtfdude1830I think it's really not that exciting anymore after you done it a few times. It's a repetitive work, that's why you see them smoking while doing it. Physically hard, but mentally must be really boring.
@@Asto508 Once you beat the barrier of 'physically hard' it definitely just becomes boring and monotonous.
@@Asto508 Yeah perhaps you are right, just like other job, its getting boring
This video really makes me appreciate how much skilled labor goes into our infrastruture. 150 of these welds a night is an incredible pace
Seeing you do a tensile test as a welder was very neat! And they ARE correct. In many cases when we do tensile tests, a perfect weld would break on either SIDE of the weld, not in the middle of the weld.
Because the weld itself, in many cases is ALWAYS stronger than the base material. Which is why we add filler metals and the like back in. But even if you didnt add filler metals, the weld should still keep the properties OF the base metal, and will only break in the Heat Affected Zone, which is why it's important to keep this zone small (especially when doing TIG welds). The smaller the zone, the less chance of failure down the line due to stresses.
Thermite Welder from the UK here! Very cool and informative, enjoyable to see the slight differences in the process they do over in Germany. Usually we just leave the Risers (the excess metal that is left behind after trimming) on the weld then knock them off once its cooled down. Personally I don't see too much of a time save in doing pre grinding as you are having to wait for the rail to cool down regardless. Plus the additional risk of potentially over grinding the rail and dipping the weld if you aren't careful!
3:56, you can clearly see he's pro, hands free smoking during work, never seen anyone more pro in my life
Smoking while welding with oxy-acetylene.
I noticed that instantly, too. Brother out there, in the night, middle of nowhere, heavy machinery around, cigarette on his mouth. That's a pro.
Pro's use short, stubby cigarette holders. You can point it at the side, away from your nose and you can plug the end with your tongue so you can breathe without constantly drawing smoke. When i smoked and worked, that little stubby holder was god send, you can easily keep working without eyes and nose stinging, and since pro's also roll their own cigarrette's, they will extinguish on their own. So, if you work and smoke, get one of those stubby holders.
Bro probably lights his cigarette on the Thermite Reaktion
@lenzelot983 😄
8:21 working with Germans in technical fields, I see that look daily. The look of, "Are you sure? You're not saying it like you're sure".
as a german in a technical field, you sure about that?
As one of my German friends often says to me "Do you know it, or do you only think it"
The way Derek said it I'd have given him a double of that look xD
In Germany we say "Sicher?" and I think its beautyful
Great to see the ingenuity of some engineer 100 years ago still has such a huge and lasting impact today. Shoutout to the Elektro Thermit team to give access and such insights into their world! Grüße nach Halle
Great video!
I work with Thermite every day for a completely different application than railroads, but still, your videos are both entertaining and educational.
The Goldschmidt crew has an incredible history and knowledge of this topic, making it a great choice for this series!
Cant wait for the next episode! 😁
26:47 NEXT?!
Let's GOOOOOO!
24:27 is what i wanted to know
Exactly. I had it in my school textbook that the gap is for expansion.
I'm used to the tuduk tuduk... Tuduk tuduk sound of a train
Its not only that, but afaik every welded rail cant go in a perfectly straight line. Since its constantly curving left and right the railway can expand by pushing itself into slightly more of a S pattern, while in winter it can slightly straighten itself out.
Really cool video!
Thank you for watching, glad you enjoyed it!
Some of these comments are beautiful. I really hope that the whole Veritasium team continues to be extremely proud of the work they do. As an educator, I am inspired by what you do. The quality of the explanations and visual demonstrations in all your videos are simply amazing.
I used to do this for a living. Worked for CN master welder. Hated the job but loved the wildlife
How much did you get paid?
Why did you hate it?
@@Dp270 $50k to $80k depending on experience and which company you land a job with.
14:15 I love the Old Timer just taking a drag in the midst of what looks like Hell.
You think that guys an old timer? Lol
I gave myself metal fever making thermite when I was about 14, bought everything off ebay bar a respirator.
I grew up in Chicago and had railroad tracks 1 block away that all the neighborhood kids played around. The tracks are elevated above the road along the back of factories. I always seen the tracks joined together with bolts and they would have braided wire connecting them as well. Never ever seen welded tracks in person.
Absolutely fascinating! The combination of chemistry and engineering in thermite welding is mind-blowing. Seeing how science is applied to something as crucial as railway construction really makes you appreciate the innovation behind our everyday infrastructure. Thanks for making this process so accessible and engaging.
Happy new year, Veritasium
Bro at 22:48 straight up a giant! Thank you rail testing man!
This really gave me a new appreciation for rails, the fact that this whole process is repeated for every. single. joint. is just crazy
Did they say "every single joint"?
Not every single joint, most joints done in the field yes. A large amount of joints would also be done using a process called Flash Butt Welding
@@plica06 I mean the one I just smoked didn't need all that.
They do have dedicated train cars that do this welding without all this hassle...
@@ArmandMaree ah ok, still pretty cool though
Happy new year derek ❤
Happy new year!!
I worked on the Eglinton LRT in Toronto back in 2021 and saw a crew of people doing this. It looked neat but I did not really get to talk to them. This video explains a lot, really well made and detailed.
Love a video that combines the concepts of microstructure in steel and Stefan-Boltzmann law. Would have loved it even more if you let the people know about the pearlier structure of the steel that was slowly cooled
Wow, this is the kind of exacting, disciplined and painstaking work we take for granted, which ultimately improves all our lives.
0:19 joining mineplex
very niche but funny
Didnt they shut it down
god tier reference
Crazy esoteric reference that brings me way back..😢
Damm this is one of the references of all time
A mind-blowing video at start of the year!!!🎉
I can't wait what's coming all throughout the year
I wish veritasium reach 20 million this year❤❤❤
Now that is a really incredible process related to Thermite and rail construction! It looks like Veritasium will soon have 17 Million subscribers! 👍👍💥💥
Happy new year to Derek and your team. Welcome to Germany 🇩🇪
03:54 - The welder is casually smoking while welding! Epic!
It's to filter out any noxious gasses from the welding process, normal procedure.
It's the same for guys working on building streets with tarmac ;-)
It is to be absolutely sure he gets ammonia.
He is from Balkan I can feel it 🤣
@@andersnilsson973 Not to be confused with pneumonia.
Thanks!
Thank you!
I like trains, and science. This video being made is a big win for me.
Very interesting. Thanks a lot and greetings from Germany 🇩🇪
The quality and determination is just spectacular!
Watching this on a 4k HDR1000 48" OLED on a desk was amazing, thanks for making all the effort required to shoot in 4K, and thanks in general for the content you make!
1:46 this gave me a Vietnam Flashback that I didn't realise I had! The Yorkshire Three Peaks Challenge was possibly the most horrendous 9 hour ordeal of my life.
But did you die, bro?
@@darksu6947haha! IDK did your mom have any children that lived? 😂😊
Thank you for giving credit to Grady in your video instead of just in the description. Your video was clearly inspired by his, so he deserves the credit in a place most people will see (and most people don't read video descriptions).
happy new year sir , i am 15 year old and love your content sir , keep uploding more about mathematics the visual explanation , science , how everything works ,
thank you
Not long ago here in Singapore a broken-down MRT metro train with a damaged bogie badly damaged a long stretch of track as it was being taken out of service and back to the depot. The damage included breaks to the running rails, damaged or destroyed trackside equipment, and damage to the power-supplying third rail; it took nearly a week before repairs were completed to a degree where passenger-service trains were able to run again over the affected stretch.
Our metro system uses continuously-welded running rails as well, and seeing how tedious and involved the process to weld the rails together is here gave me a better understanding and appreciation of why it took the railway engineers so much time to repair the damaged tracks - having to cut out the broken rails, splice in the new rails, aligning them properly, welding them together to the required strength, and grinding them down to make them smooth, and all that was just for the running rails (they had to repair or replace all of the other damaged trackside equipment and third rail as well, which is probably its own involved process I’m sure). Given the temperature requirements they probably couldn’t do the rail-welding procedure during the day, and they almost certainly couldn’t do it during rainy weather as well because of potential water contamination, which is made worse by our temperamental weather especially around the time when that whole incident occurred.
@07:55 the guy with a cig hanging from his lip means he's a pro at his craft!
19:07 "Finally they will ride above our welds"
Almost sounds like a threat in a German accent.
Watching this after the New Year’s party makes a perfect end for the night
When you heard "rail" and "line" amidst the new years cheering, I don't think this video was what your friends were calling for.
All those night-time shots of the operators building the rails went SO HARD. Great filming
Shoutout to Grady! I love Practical Engineering
3:55 Professionals with proper safety precautions and the guy welding is smoking!
I go out to the rail, I have a coffee, a cigarette, maybe some chocolate, I weld some rail, I have another cigarette... It's the euro way.
you know he is professional , because of that cigarette
If you see a guy working with both hands and a cigarette hanging from his mouth you know he's been doing it for years 😂
You get nervours IF the guys stops smoking. As long as you see him like that everyting is fine. :D
That's how you know he knows what he's doing.
0:39 "There is one sound that everyone associates with railroads"
*Banjo*
That’s exactly what my brain said!
BTW: the signature sound is still there, just less often: every time you cross a railroad-switch.
Great video, makes you realize how precise and hard these orange-collar workers work and let's you appreciate their work more therefore!