It's simpler than you think, and makes a ton of sense when you know the bits that go into it... Visit the channel shop: hycetrains.com... Join my discord: / discord Become an ES&D Train Crew Member and get extra perks! / @hyce777
Or as a former Class I engineer dealing with power desks that were miserly with the horsepower, I liked to say, "I love the smell of burning traction motors in the morning, it smells like overtime!" 😆
11:10 The complete motive power adage can be summarised like this: * Steam can pull a train it cannnot start, * Diesel can start a train it cannnot pull, * Electric can start a train and pull it fast, but what about switching with electric? Forget it.
@@mafarnz The high infrastructure costs are still there, making electric switchers seldom practical, unless entire switching is confined to already electrified portion.
Electric freight trains!? Getta outtahere this is America. It's a big country. This isn't the dainty hills of Norway. We need power!! SPEED!! We need liquid hydrogen fueled rocket engine powered trains. Probably about x2 Saturn V F-1s strapped to a tanker car on the back outta do it. Your ETD won't survive unfortunately but the exhaust will melt the train circuit components anyway so there's no problem there the company will know your train passed through.
hybrid, battery electric, and occasionally even electric shunters are a thing. In switzerland the Eem 923, Aem 940, and alstom prima H3 (doesn’t have a swiss designation) are taking over a lot of shunting work. For passenger shunting, we also have the Ee 922, which is the electric brother of the Eem 923, since passenger train yards often need catenary for modern EMUs anyway, they might as well be used for shunting passenger cars too.
@@mafarnz@robnobert Its a "final mile" problem, just like power-wires at home. There is easily more distance of wire between every houses fuse box and the closest power poll than runs down the street. Easily more down every street to substation than between substation and power plant ect. So the big impressive feats of engineering embody a lot less of the work and cost than the little stuff. Its extremely affordable to electrify between two cities, but to put more miles of wire into yard tracks that might see only a few cars at a few miles an hour? Uneconomical at its extreme, and its not a "buy once, cry one" type equation either, your maintaining all that infrastructure in situ rather than having a single fueling stand and maintenance shed for the motors, to work inside under lights, not out in the weather. Also one failed shunter is a nothing for meeting schedule, it can be dead towed out of the way and still leave you with just as many operational on the day (there are always a few waiting, or down for routine maintenance that can wait till tomorrow), but a single failed insulator will kill power to most (if not all) the yard. Also loading things onto cars underneath traction wires with cranes ect is more difficult, and 3rd rail systems make switches more expensive and yards more dangerous for operators who are working on foot. The one coming technology that could change that paradigm is batteries, totally useless for the continuous output of mainline freight, lacking the range for intercity passenger and less safe, heavier and more costly than systems to allow controlled back-feed on EMU services (which currently are using rheostatic dumps, despite power actually being the most expensive part of train operations, just ahead of crew costs, and far over track/wire maintiance on busy routes), small (and often remote operated) battery shunts allow for lower fuel costs/emissions within yards, and are easily rotatable to keep units charging. Yes the batteries will wear out but it will sum to less cost than difference between fuel and power, and unlike automotive applications they don't need the extreme power/weight, and can be far more durable/stable and standardized/recylable, so it might not even be the human/environmental disaster of large electric luxury cars. Or who knows, we might see the technological promise then find some new way to mess up just as badly, time will tell.
Something I've heard through my time in college regarding internal combustion VS electric motors goes something like this: "It's easy to keep an internal combustion engine from starting but don't try to stop it once it's going. It's hard to keep an electric motor from starting but it's easy to bog down." Feel like that's appropriate here given what you've mentioned.
As a Brit used to driving cars manual gearboxes, I can assure you it is very easy to stop a petrol (gasoline) internal combustion engine when it's running.
Hi Mark, before this excellent tutorial I knew very little about diesel tractive effort. I now understand this better and why HP is so important to diesel vs. tractive effort. Also, for someone like me being afraid of math, you take formulas that sound complicated and you make them understandable. Thank you Professor for another great 101 episode, and as always cheers to you!
You still don't know much...Power output and traction effort are related and one in the same. There is no one or the other. They are related in the exact same way for steam locomotives. Unfortunately, Hyce does not understand this relationship, and should not have made this video. He knows just enough to be dangerous 😂
The whole "TE Equation" "Drag Rating" "Maximum Starting TE" "Min. Speed for Full HP" conversation still is one of my favorite subjects to nerd out about. Like, the TE equation works pretty well at any speed above the Min. Speed for Full HP, but as you bog down past that speed (depending slightly on the locomotive) you'll start to lose horsepower, but still gain TE (just not fast enough to keep your horsepower up). Then, once you reach the "Drag Rating" speed, the excitation system (specifically the feedback comparison portion) is designed to limit current from the main to the maximum continuous rating of the main or TMs (whichever is lower). If you continue to bog down, *some* locomotives are equipped with special components in the feedback comparison portion of the excitation control that will allow the main to put out above the continuous rated current. This will continue to go up until you reach the "Max Starting" Tractive effort. Trouble is, if the engineer doesn't watch what they're doing, they'll roach a TM (or the main, or both) by operating in this rang for too long. That's still a bit simplified and this all can vary based on locomotive model, age, and manufacturer, but it's such a nerdy thing that I love going on about. Great video as usual, and I was glad to hear you elaborate on some of the more complex things about diesel tractive effort calculations.
Ahhh Math. My worst subject in school, usually any video that involves this gets the ole skip button. It's basically an ad to me. Usually. If there's anyone and anything who can get me interested in math, it's Hyce and trains.
Just for reference: SD70Ace TE = 850 kN (starting) & 700 kN (continuous) Big Boy TE = 602 kN As for HP, the SD70Ace has 4500 versus the Big Boy's 7000. Hence why the Big Boy will pull any train it can start faster than the SD70, however SD70 will start a much heavier train thanks to its higher TE at low speeds.
My father was an engineer for 42 years. According to Dad, "A steam locomotive will pull anything you hook to it, as long as the boiler doesn't explode. Just keep pouring coal to it." Lol. Miss you Dad.
🎵Come with me, and you’ll be, in a world of FRA destruction! Take a look, and you’ll see what it means to violate rule G. You’ll begin, with a grin, smashing trains in head on collisions. Working there, run red boards, if Mark Huber does decree.🎵. (I leave it to the comments section to continue the parody)
Steam locomotives are power limited as well. There's only so much steam it can generate per hour. The largest are roughly equivalent in power to the largest diesel locomotives. If you compare the torque curves of electric traction motors to steam locomotives they are more similar than you let on. Like any vehicle, the power available to be converted into tractive effort by a diesel-electric locomotive is not equal at all speeds, so the real-world speed-tractive effort curve looks nothing like an ideal 1/x curve.
Very true, just like you have to live with the electrical supply you also have to live with the steam generation supply. That said working harder helps you in that space.
100% there is a limit to how much steam in an hour (though as Hyce says, both blast pipe and locomotive speed help drag more air through), thus even when aiming for max power you reduce the valve cutoff as the train speeds up, but there is also a pretty big capacitive effect in the heat within the boiler (a lot more than merely the volume*pressure of the steam that is already a gas, hence why compressed air locomotives never did well even in underground mine work) so you can throw the bar to the corner at fairly high speeds (at extreme speeds the flow through valves/piping starts to be a limit) and put out most of the torque you would at 10mph for a couple of minutes. But the reason that the seemingly simpler boiler comparison is not done is people avoid using any equation from steam horsepower for trains because even within one region/era represent vastly different nameplate specifications, and between different times or regions its just completely incomparable. Its pretty common to see a 400hp and 1,200hp train of about the same size, number of boiler tubes, firebox area, and see them do about the same work, while a historic "40hp" locomotive did vastly more than one tenth the work. Meanwhile the pressure, cylinder area and wheel are very rigid numbers with limited error, and their relationships are nice and linear/intuitive (twice the pressure or twice the area both double hp or tractive effort in their respective equations). That said the power available to be converted into tractor effort by a diesel-electric doesn't depend at all on speed, some of them literally have hook up kits to provide grid power for remote deployed or emergency applications. And above a certain (and fairly low) speed, the curve looks exactly like the 1/x curve.
@@SheepInACartGreat explanation. There is a limit for "sustained horsepower" for steam locomotives, but this is highly dependent on the crew. If your fireman is tired the sustained HP rating will be deteriorated. So any "sustained HP" rating on a spec sheet would need to be accompanied by a big asterisk. Also interesting about using the capacitance of the system. If you are "consuming" that buffer, you can put out significantly more HP than your sustained HP during shorter bursts.
@@Hyce777 Exactly. Heat is GOOD for a steam engine, but BAD for diesel engines and electric motors. Steam gets more efficient the hotter it gets (to material limits of course).
@@hallkbrdz That is not entirely true. Diesel engines are very much thermodynamic heat engines, like steam engines. The hotter they run, the more power and efficient they are. Up to the point when they cook the lubricant, which is the exact same problem with steam locomotive in lubricating the cylinders when exposed to superheated steam. It is true for electric motors. They are more efficient the cooler they run.
I've read articles and seen videos on SD70 MACs crawling up grades at less than 2 mph! I don't know how long these big Locos can sustain that effort, but AC traction motors seem to offer advantages for pulling heavy trains over steep grades.
EMDs Creep Control is a lifesaver in scenarios like that. It allows for minimal slipping of the wheels before it reduces power, because a little slip is better than no movement...
This is like 3rd hand information so take it with a grain of salt, but I once talked to a guy who used to work for NS, and he told me that when they wanted to demonstrate the AC traction system, they took a loaded coal drag, underpowered it, ran it up a hill in 8th notch until it stalled, set air and handbrakes, went to lunch, and came back an hour later to find the locomotives still giving it all they had. He said they designed everything so that the control system wouldn't pass enough current to burn up anything. He also said they claimed that the AC motors are so robust that the inverters for the VFDs in the aux cab will fail before the motors do. AC traction really is some crazy stuff.
@@CDROM-lq9iz Oh hey, fancy seeing you here! Yeah, I doubt they would tie up the line like that, but I don't doubt the possibility of the results one bit. I hear tell the "AC" stands for the word for "magic" in Hogger Latin...
@@PowerTrain611 Same to you! Like I said, this is like 3rd hand information, I wouldn't be surprised if they picked a siding or the company had a test line or something.
A lot of European railways are going for bi mode locomotives which are basically an electric loco with a diesel generator added. In many cases the diesel engine is quite small but they still could exert the same maximum starting tractive effort (and move the same load) although speeds would be limited which is ok for shunting or working a short slow speed branch lines, on a mainly electrified network. A typical example is British railways class 88. For shunting there seams to be an interest in battery or hybrid power. Clayton engineering in the UK has built several recently for industrial applications with battery recharging from either a small onboard generator, a shore supply or line supply, For operations where operation is highly intermittent battery is ideal. There is even a project in the UK to convert an ancient 08 shunter to hybrid operation
i was always a bit confused about the relationship between horsepower vs TE, and why people would say steam could outpul diesel. this definitely clarifies some of that confusion, thanks !
You are so right. Even in train simulators it's so easy to start a freight train with several diesel-electric engines because of their huge tractive effort at low speed, but you need more engines if you want to move faster, but after a certain speed, a 4400 hp diesel loco and a 4400 hp steam loco, they both perform the same. In my opinion, if they electrify their networks, they can run much more powerful locos and start thinking in tractive effort again.
In the words of Uncle Pete mechanical helping me troubleshoot over the radio: "Well its dead. I guess we're just moving trains on hopes and dreams now." On our class 1, we use TPA (Tons per Powered Axle) to figure out what our power needs are. Train Tonnage / EPA = TPA. Lets say our TPA limit for a subdivision is 500, we need enough EPA to get us to, or below 500 on TPA. EPA: An Equivalent (powered) Axle is a locomotive's tractive effort or braking effort compared to one standard axle which has 10,000 lbs. tractive effort or 10,000 lbs. braking effort. A SD70ACe is rated at 14.4 EPA, times that by 500 and you get 7200. Thats the max tons that engine can pull on its own before you need more power.
Thank you for this explanation. Puts perspective in what was said to me 2 years ago standing on top of CN6060 in restoration. Was ask if I saw it run? I said no. The engineer that was with me said it is the hand of God pulling. Said they hardly ever get into the throttle in excursion service.
A conductor once told about inter-terminal drags working up the hill to Bayview using a match-book inserted into the relays to prevent tripping due to short-time issues. These were on switch engines built in the late 1940's and 1950's. A related topic -draw-bar limits.
Really great video! Helps put in perspective part of why some applications were slow to switch to alternatives to steam & others held on a lot longer. Then of course there's stationary applications for electrical generation for a town or mine etc. Great topic!
Great video! I look at it as power impulse spacing. At starting, Mechanical/Steam is very abrupt, electric is smooth. It all comes down to adhesion coefficient. Exceed that and you just spin. If piston / steam was as cheap to run as diesel / electric they could have mixed power and get the best of both, great starting power of electric and high speed power of steam!!!
I think you need to take a step back and look at the forest, rather than this specific tree. Steam doesn't more more horsepower per ton than modern diesel or electric. Impulse spacing is a consideration for the engineer starting a train but not a binding restriction on the power specified for any real world route/application. At low speeds these are are NOT sinusoidal power phases, in a simple 2 cylinder steam engine at max cylinder cutoff the valve remains open to steam chest almost the entire way to exhaust, your talking falling to 50% power for 10% of a rotation 2x per rotation, with far more slack in the draft gear along the train than period of reduced power even if you where unlucky enough to be stopped at the worst rotation. 3 cylinder locomotives existed where more area was desired but either loading gauge or inertial forces didn't allow the 2 cylinders to be larger, it wasn't worth the cost in any context a simple twin could just be upscaled. So in neither context was there any even theoretical benefit to a hybrid system. Diesel and electric can already wheel-slip, so steam cannot help them start a heavier train, even if somehow it didn't add any extra cost at all. You know what does start heavier trains? Slugs. Simple railcars of concrete ballast with traction motors under them.. and they are rare because desired freight speeds are fairly high, and beating hard on less equipment often costs simlar money than being gentler on more equipment that can be less specialized.
The really cool thing about AC traction motors is that there is no minimum speed requirement. And can pull at zero mph and not birds nest the traction motors. Helpers can push in the slack until they cannot push any further. Then when the train is ready to start, the lead locomotives will begin to pull. And the train begins to move. This is the kind of train handling that was done in the days of steam. I remember reading that in a railroad publication when AC locomotives were first introduced.
So the gist of the matter, as i understand it is; that a steam engine is basically a piston engine connected directly to the drivers. This means that, like an internal combustion engine, it has a torque curve and corresponding horsepower curve. And apart from the "dead-spots" at the end of piston travel when going slow, the torque curve is pretty flat at low speeds and tapers off approaching top speed. So rising horsepower as the engine goes faster, until the torque starts dropping off. In contrast a diesel-electric locomotive has essentially an infinitely variable gear ratio between the engine and the drivers, in the form of the generator and traction motors. This means, that the engine can run at its optimal speed, generating full power regardless of the wheel speed. And since torque and horsepower are related through rotational speed; gearing any amount of power down to near 0 RPM, means near infinite torque.
One big thing that you didn’t mention is diesel electric locomotive transition where the locomotive motors go from series to series/ paralle at about 20mph The various formulas for modern trains is basically Horsepower per ton Or Tons per equivalent power axel So like a motor GE can be up 14.4 equivalent power axle
hyce I have been watching you for 3 years I love your vids and live streams I hope to become a train engineer one day just like you Hyce I really wish I could be a train conductor but I’m to young lol but thanks all you do hyce! -ETandwncrailfan
I remember coming across a video a while back that they're experimenting with new steam locos in the UK. Would be interesting to hear your take on it. IIRC, they're using steam generators to turn hydrogen with atmospheric oxygen into steam to turn a turbine to generate electricity to turn motors to turn the wheels. I scoffed at it myself, sounds like a lot of trouble over what could be solved more simply with just electrification. (Not to mention, hydrogen production isn't exactly clean unless you want to go the nuclear electrolysis route.)
let me tell you some practical experince from being a fork truck tech, and yes they are more alike then you think. Another issue with motors is shaft whip, Ac brushless motors are absurd, they can tear themselves apart they are so powerful. It makes a lot of sense to hook multiple engines to reduce load beacuse the motors work best at certain rpm ranges and laod ranges so your not melting stuff or tearing up shaft bearings
Small thing that’s closer to trivia than critical. British Imperial measures != US Customary measures. The differences are generally fairly minor but they are still these. Amusingly both are defined in metric so they’re just metric with extra steps. :P Seriously, NIST defined US measure in metric in the 1930s if not earlier. You can find the publications from the time with it.
thank you for the nerdy lesson! I fetched writing materials and took notes because .... because. Amazing how fast diesel locomotives lose it getting up to speed. No wonder PSR is cursed at so much. I think one would represent the lower limit of those traction motors by drawing a horizontal line on the graph at a certain maximum T.E. Right?
@@Hyce777 Depends on how old the locomotive is. Older locomotives didn't have any kind of regulation for loading other than the Load Regulator. As such, those old engines would let you have full horsepower pretty much right off the rip. (F them traction motors lol) We had a GP11 in our shop not too long ago that would pin the ammeter in 3rd notch from a dead stop. *Edit: This is actually why EMD talked about their early diesels having full horsepower available right away. That fact is also why early diesels ran steamers right out of the switchyards. Modern "road switcher" or "line haul" style locomotives limit TM amperage (and thus tractive effort) at low speeds to protect equipment.* As much as I'd love to ramble about excitation control on newer engines, I'll refrain. Suffice it to say, roughly Dash-2 era EMDs would follow the curve for the equation until the "min speed for full hp" and then would follow a slightly less steep line down until "continuous drag" speed and then follow an even shallower line down to stall. Newer locomotives (i.e. Dash-3s and newer) use a more sophisticated system yet that probably does get alot closer to that flat line that was mentioned.
TE in diesels is something I've been trying to figure out for a long time. It seems to me there are so many more factors that play in. Most importantly is weight, and # of axles, and type of traction motors. You have to have enough weight for your motors to apply the effort. If you look at a 1750hp SD9 and a 3000hp SD40, they both say 90000 starting from info I've seen. But the SD9 drops off significantly faster than the SD40. However if you look at the SD40, SD45, and SD50. 3000, 3600, and 3500hp respectively, their starting tractive effort is almost identical, their weight is almost the same. I've read the SD45 has no advantage over the SD40 at low speed due to adhesion limitations. My next example is the SD60 (3800hp), SD70M and SD70MAC (4000, later 4300). SD60 makes 105,000-110,000 starting and continous at 13mph. It weighs less than the SD70 but more than the SD40. The SD70s had a new wheel truck design and the AC motors could make 160,000 starting and 137,000 continuous I believe. This leads me to believe if the SD60 was heavier it would make much higher starting figures as it is adhesion limited. Last example is a B40-8 vs a C40-8. 4 axle making 68,000 vs. 6 axle making 108,000. I would have to believe that these higher hp engines make way more power than 4 traction motors can even use at low speed, but at high speed there would be more power available for 4 axles vs. 6, allowing the motor to create more torque. Most electric motors will backfeed voltage as they turn faster, requiring the alternator to step up output voltage to overcome tte backfeeding and maintain voltage potential. I'm not sure on gearing numbers on these units but since a motor uses more amperage at low speed, changing the gearing to make the motor run slower at fast speeds would effectively increase TE at high speeds. Just some thoughts on my findings.
Hyce- On a traction motor, the rpm is not as much a problem as heat on the low end. The minimum continuous speed is more about heat dissipation than anything else. GE's 752 traction motor was insulated better than EMD's D series up until the AC era. So at a given horespower, an ALCo or GE unit had a lower minimum continuous speed than an EMD. Road units tend to have larger motor blowers than switch engines, whereas switch engines generally had much less horespower. EMD's E-units with their 33" wheels and 90+ MPH gearing had a minimum continuous speed of 33 MPH. The overall point is, railroads and manufacturers use two primary minimum continuous speed ratings: 1) Slowest speed you can use full throttle without damaging the traction motors. BN, BNSF and NS used a speed-it is a little arbitrary as you can still overamp the motors. Many motors still have it marked or placarded somewhere as noted below 2) The placard you show is common on most 2nd generation motors showing an amp load and time limit. Various railroads have various procedures for cooling the TM's down if the limits are exceeded. On the efficiency side, 82% is a reasonable number for pre-electronic controlled traction, electrical and engine systems. A modern AC unit is around 93%. I grew up running EMD SD7/9's, they really did not have a minimum speed. You could stall burn them if not careful. Our former SP unit we have had D78 traction motors, SP had rated its minimum speed at 3 MPH. Odd thing was at 3 MPH, you were already down to 1000 amps. ALCo's had some units like RSD-4/5's and 12's(maybe even the C628) that did not have minimum ratings. They simply said follow the amp meter markings.
So what you're telling me is that the traditional Big Boy caravan is the perfect train. A diesel to start a train it cant pull and a steam loco to pull a train it cant start.
I mean really the confounding factor here is the electric traction motors, not really anything to do with the diesel. You pair the big boy up with one of those road engines full of lithium ion batteries that are supposed to be paired with a couple of diesels. Then you can launch with it, it comes with all the modern signaling gear you need, and when you want to make the big boy look more impressive you run the dynamic brake, Big boy makes a lot of smoke and steam and you get the energy back in the batteries.
True, i suppose. But, in the modern Big Boy caravan there isn't enough tonnage being pulled for either Big Boy nor the diesel to even notice anything is back there. The caravan is a short little passenger train full of mostly air. Now that Big Boy 4014 has been outfitted with PTC, the diesel is still there only to provide dynamic braking to save wear and tear on Big Boy's crazy expensive and now-custom brake shoes (the local AutoZones along the route don't stock them for some reason!), and to provide emergency backup power in case something on Big Boy breaks. So, the diesel is still in the consist for both "brakes" AND "breaks"!
None of what you said applies to modern AC Frequency Drive Induction motor locomotives. Technology has changed drastically in the past 30 years and it seems like Hyce has missed that boat with his explanation.
Honestly I think one of the simplest ways to understand this is that the actual *engine* of a diesel locomotive operates at a fixed RPM, while the engine of a steam loco operates at the RPM of the wheels (at least unless its a shay :P)
The only diesel electrics that are always in Run 8 are the Amtrak passenger engines because of the HEP need. Diesel RPM increases as the throttle is advanced through Run 1 to Run 8 which is the maximum diesel RPM. Units of any train climbing any ruling grade will be in Run 8 no matter the train speed unless they are light or have a minimum loaded train.
For the next Tractive Effort 101, is it over the Handcar? Basically, it has a small value due to it being man powered, but it can do some work. IE the average man can output a strength of (Lets use me for the sense of things) 200 pounds of force on my arms. With the gears on my own, I can make lets say a TE of 300 due to gears, wheel size, amount of people, how much said people have strengh wise, and speed. Does it make sense what I am trying to ask? Yes this sounds like a joke question but I am curious if there even is a way to figure it out yet, or if it needs to be make with trial and error.
@@Hyce777 I am more than willing to do a few laps or moves around the museum to figure it out. Or I can do some weight measurements to figure out a theoretical average output strength of a blue collar worker. Although if the museum or yourself has a photo or drawing of the handcart the museum uses, I could figure it out so you could do a short video on it.
Interesting anecdote. Back in the day the SE Railroad Museum had a family field day. They had handcar races timed laps. The wives bold enough to do it, and me, took a turn. We started with wheel slip. The guys thought it was a fluke, we did another lap with the same starting wheel slip. Our total time was close to the various guys teams but no slips from them. I could only think the combined weight was lighter just enough to get slippage. True the rails were greased to lessen flange squeal and reduce wear on the tight curves.
I think this would be pretty much the same with a straight electric powertrain. The source of power shouldn't matter, it can be a "diesel generator" as in the diesel-electric powertrain, or an overhead contact system, or even a battery. An electric motor-based traction system has basically the same characteristics, no matter the power source. Even the DC traction motors and VFD (power converter)-driven AC synchronous or asynchronous motors behave similarly, given the limited amount of power available from any of the sources. The reality is that you can't get more power out of a traction motor than what you can supply, and torque (tractive effort) basically depends on supplied power and motor RPM. Given the maximum amount of constant power you can supply to a traction motor, as the RPM increases, torque drops because this way the power put out to the shaft dosen't change(as well as the input power). With a steam engine you can put out more power as speed increases, because increasing RPM inherently increases steam usage, so you dinamically put more power into the engine by going faster, using more steam.
Steam engines do have horsepower limit, as the cross-section of steam passageways is finite and steam can be admitted into cylinders at high speeds only so fast. Regarding electrics, there is a big difference. On diesel traction motors cannot physically develop more horsepower than the prime mover does. On electric loco, there is no such restriction - by drawing amps above continuous rating the driver can squeeze extra hp for a limited time. A typical 1960-era 6-axle electric may have about 4000 hp continuous rating, but is able to run at 4500 hp for up to one hour.
Considering what you say here, the railroads tend to push the limits of this. I wonder about the huge cross country trains that are > 3 miles in length. As a railfan I often hear engineers telling dispatch that one of their engines (power units) is inefficient or failing. Is it worth all of that power (and diesel usage) to save a few man hours? There must be a maximum length (OK weight) that is feasible to pull in one train (even disregarding the other issues like siding lengths or trouble if a mechanical problem develops in the middle of the train). Fascinating info, Thank you.
Hey Hyce, I know this isn't really related to the video itself, but the locomotive in the thumbnail kinda looks like it might've been used as inspiration for, at least the front profile of, Satisfactory's Electric Locomotive, nicknamed Leif by the employees of the in-game company FICSIT because of its reliability.
Question for you about traction motors. Let's say for really heavy moving, you put 4 out of 6 lower geared for start pulling, then the other 2 are higher geared, that way you could run at higher speeds. But you would probably need and extra engine for start pull power. Was an idea.
It does not really matter all that much. Gearing is there to step down high RPM motor to low RPM wheel and the specific sizes have more to do with making sure the motor is not oversped and mechanically the entire assembly can carry the design torque. For any electric tracton its 'gearbox' is in the electrical cabinet.
All I heard is that we need Steam + Diesel Electric Hybrid Locomotives, that have both the steam drive and the electric portion in one combined locomotive
Its the same Phenomenon. When it comes to the rotary and pisiton engine The rotary engine can start something it cannot pull and the pisiton engine can pull something it cannot start Why Look at the fundamental design of each
At slow speeds the Tractove effort is limited by traction the electric motors are only in danger at a stall or very slow speeds maybe 1-3 mph at full amps because the brush will weld to the commutator
And this is why once you start using traction motors, the diesel engine ends up being the limiting factor. This is why so many countries use overhead wire/catenary electric locomotives. You can get the same job done with fewer locomotives. Sure it costs more to setup but you get locomotives that can be much more powerful as they have a large external, remote power supply (an actual powerplant or a few). Horsepower, so much horsepower... Or should I say kilowatts, so many kilowatts.
Easy Lemon Pepper Chicken 1-2lbs of whatever chicken you want, adjust oil to compensate Zest and juice from 1 good sized lemon (optional, but worth it) 1-4 Tablespoons olive oil (use more if no lemon) (to taste) Your favorite lemon pepper seasoning, I'm partial to the one from Badia Breadcrumbs (optional) Prep the chicken to be about 1" thick, or just use bone-in things or wings or smthn Mix olive oil, lemon juice, lemon zest, and seasoning Toss prepped chicken in the mixture and marinade 20mins-overnight (I like to prep it in the morming to eat for dinner) Place marinated chicken on wire rack placed in a baking sheet (to catch juices) Sprinkle breadcrumbs over chicken (optional) Bake at 425F for 35-40 mins or until safe to eat (165F internal) You can also pan-fry or air-fry, both are good options but the oven has the least work involved Goes well with asparagus imo, and served over rice, or you can eat it with no sides lol
Actually, this is perfect timing for this. I was going to look for a recipe like this when I got off from work, now all I have to do is send this to my email. Thanks for saving me time, Mikely!
@hyce way off the topic of this video, but I’m curious about something. A ways back you posted a short about a cursed steam loco on Leighton’s layout that had a tender in front of and behind the actual locomotive and the driver wheel sets were under the tenders and not the loco. I’m curious because, to me, that seems like it could potentially solve some issues stemming from having the drivers under the boiler. I’m also just wondering if that sort of thing would even function at all if you used extreme high pressure steam hoses for any connections requiring the flexibility around turns and such. Anyways, thx for the super entertaining/informative video, as always:) have fun.
If you keep adding locomotives, you pull out the drawbars. You’ll need to put locos in the middle. This is done in Queensland, Not sure if locos in the middle of the train are done in US.
Great piece as always. So, on a steam loco with a booster engine, the booster is intended to compensate for the variable torque at very slow speeds because of position of the pistons? I’m not quite sure I understand the piston position issue. Do you have a video that deals with this?
That is precisely it. I'm not sure I've got a specific video that addresses it - but basically there are dead spots in each wheel's travel where the rod isn't really doing much to the crank - front and back dead center, and near there. So at slow speeds, you'll get to the point where half of the engine doesn't supply any force at those spots, halving power output, and stopping things dead. At faster speeds, the time at those spots is so minimal momentum carries you through, and you don't have to worry about it.
@@Pamudder Basically, a steam locomotive has 2 steam engines coupled together through the driving axles but the connections are offset by 90* so that the locomotive can be started in any position. When one side is at 0 power or thrust or top dead center, the other side is at full power
BNSF has changed their formula for figuring horsepower. For DC locomotives it's the same, but for AC locomotives they get their rated horsepower goosed up to over 5000 HP on account of less wheel slip. Even though their diesel engines may still be 4400 HP. It's good and bad for TY&E. It's good that the company has finally also admitted that the GE C4s with only 4 traction motors are bad to put on a heavy train running over a subdivision with hills. So maybe we'll get fewer loaded unit trains built on flatter subs with all Dash 9s and C4s that stall on more hilly subs, and the company can't figure out why. "On Paper, you have plenty of HPT!" But bad because with the new GE 216 ton 6 traction motor AC locomotives, some coal sets that used to run 2x3, with some throttle restrictions, but you could exceed that when you were below 15 mph going uphill, now will be 2x2 with the new GE heavies, but the trail unit on the head end will be in DB Only unless on the absolute hilliest subdivisions. I admit, it does work okay on dry rails, but there's no margin for error for inclement weather, and getting approval to put the 4th unit in run doesn't seem like it's either easy, or fun.
Worth noting that just as you can't maintain max horsepower at slow speeds because adhesion or heating limits, you can't maintain max horsepower at very high speeds because of voltage limits. Faster you go, the more voltage series wound DC motors need to maintain a constant horsepower, and if you only provide a constant voltage then the horsepower drops with speed. And that's why the difference between an SW1500 and GP15 matters-both are rated at 1500 horsepower and can pull the same, but the SW1500 can only maintain that full power output to about 21 mph. The GP15, on the other hand, can maintain full power output up to its maximum speed (GP15 has transition allowing motors to receive higher voltage as speed increases, most SW1500s do not), which means it straight up pulls better than an SW1500 at higher speeds-useful if you ever intend to take the train out of the yard.
I've wondered a similar thing about something like a GP35 vs a GP40. Like you said, transition can affect the performance of the locomotive depending on the speed you're going, which is why an SD40 will pull about 50% more than a GP40 at low speeds. I wonder if a GP35 could outpull a GP40 in a short burst at low speeds because of the same thing. If I'm not mistaken a GP35 and GP40 weigh about the same, but only the GP35 will start in series, meaning the main can deliver more current since it's only feeding 2 paths instead of 4.
@@CDROM-lq9iz GP35 won't outpull GP40, because the former's main generator is D32 DC unit rated at 1700 A, whereas GP40's AR10-D14 is AC capable of 4200 A continuous current. The low max amperage of DC requires a transition, while much higher current of the alternator allows to eliminate it.
@@Knsgf if my memory serves me right, a d32 main is rated for 2900 amps of continuous current. Across two series paths, that'll give you 1450amps on 4 motors. A GP40 with an AR10 will start in parallel which only gives you 1050amps on 4 motors. Edit: anecdotally, I've seen alarms on our gp35s where the main managed to pass over 4000 amps of current.
Thanks that helps! could 102 be Gearing? Like more info about Passenger/commuter diesels engine gearing, compared to Freight locos gearing. I hear the F-40's get beat to hell at full throttle all day long. I'm mot sure if this is still the same thought but maybe explanation of why the commonality of the B-B trucks and C-C trucks on Diesel locos here in the USA
Electric motor torque decreases with speed..... but I thought that due to the reverser(?) or whatever making the valves supply steam for less and less time as speed increases you would have the same effect on a steam loco? Y'know the reduction towards the end of the piston stroke thing, I'm tired sorry.
There is no "minimum speed" on a diesel locomotive. There is a minimum time rating at high output(amperage). Its called short time rating and it has to do with throttle and rotation of the motor. With high amperage the motor gets very hot when it absorbs the energy. If you keep the throttle and amperage below the short time rating for any type of locomotive you can run at as low a speed as it will go (As tonnage allows). The counter EMF is what takes away the energy in the motor as it rotates faster.
The HP rating of steam has always seemed a little weird. Even with cars and tractors they’d get rated at say 20Hp when in reality they could often produce much more. I think steam introduces a few extra variables that can make power ratings a little fuzzy.
Long story short, the power is always the ultimately limiting/dictating factor, be it diesel, steam or anything else. The fact that diesel electric systems theoretically can produce infinite torque at standstill doesn't mean they're worse than steam at high speeds, the steam engines also has to be able to produce the power required for that tractive effort at high speeds as the diesel electric ones has to be able to produce for a given tractive effort at the same speed. So, it's not that diesel electric has to produce a lot of power to generate a lot of tractive effort at high speeds, because that is also true for steam engines, the difference is that steam engines are unable to produce a lot of power at low speeds because their ability to generate power essentially increase with the speed, assuming constant steam pressure, and neglecting some variables that should be minor within the speed range they're designed for.
I'm confused as allways. "I WENT TO COLLEGE" Plankton quote,! Makes my head hurt. Math. You young wiper snatches n your funny formulas 🥴🥴🥴🥴🥴 I Do know that a small block Chevy 327. Bored 30 thousands. Comes out to 331. Had one in my 56 Chevy😭😭😭😭More bango on the train vids 🪕🪕🪕🚂🚂🚂🎸🎸🎸🦜🦜🦜🍊🍊🥓🥓🤬🔥✅✅❤️Thanks for noticing!! William
So, what I'm hearing is that the ideal locomotive (in spherical cattle language) is some kind of fission-steam abomination with an electric starter motor-majigger?
I'm not a railroader, but my work has caused me to be involved with simulating electric motors. I don't understand the cause of why a diesel loco and a steam loco don't have the same performance as both work by expanding a hot gas (not steam isn't a gas) in a cylinder. (It would be interesting to know if a torque curve like a car or truck diesel engine). So, I'm wondering if the cause isn't the diesel engine itself, but rather the electric traction motors. Most diesel locos are diesel electric, (in the 1950s the UK built some diesel-hydraulic locos and I believe that some shunters are direct drive), and an electric motor only produces maximum torque when there is slip between the rotor's speed and the "speed" of the rotating magnetic field in the stator.
I plan to do this in my current Transport Fever 2 save once diesels open up, I'll see if it simulates this. ...Eventually, school's back and I have a game backlog.
Or a Diesel train with steam helper. B&O passenger westbound out of Cumberland with a steam helper pushing, 1956. Might have been one of the last times that happened.
The issue is the electric motors struggle at high rpm, right? Have a water filled tender with steam drive system. Above a certain speed use the diesel generator and/or exhaust heat to create steam and drive the pistons.
Hey Hyce, can you explain for me what is going on with the large amount of steam that appears to be blowing out around the cylinders when a steam engine starts up, but then when the train is underway abruptly stops? I've long wondered what's going on with that, and you're the best person I can think of to explain it. TIA, Audry.
When a steam locomotive stops for longer than say 10 minutes or so, the cylinders cool enough to condense some of the steam into water when the steam enters the cylinders. After the train starts moving and water stops coming out of the cylinder cocks, the valves under the cylinders are used to expel water or wet steam, the cylinder cocks are closed to keep all of the steam in the cylinders. Does that answer your question satisfactorily?
Not Hyce, but I believe I know what it is that you're asking about. When a steam locomotive is stationary, the steam that is in its cylinders will begin to cool down, which will cause it to condense back into liquid water. Water, being incompressible in a very bad thing to have in your cylinders so they have valves called cylinder cocks attached to the cylinders that allow steam and water to vented out. Once the engineer is sure that there is no more water in the cylinders the cylinder cocks are closed to avoid wasting steam.
Question... so if I have a sh!t box 45 tonner with a single tranction moter and generator but dual alternators... should it be able to go over 400 volts dc with throttle at max? Just seems it isnt building power properly when facing any form of resistance including a .5 percent grade qhere it resides.
