Diesel 101 - How DIESEL LOCOMOTIVES Work! [10 Levels]

hey guys this is heiss and we are back at you with another 101 course 10 levels of understanding and this time we are talking about diesel locomotives and i'm sure i'm going to get myself in trouble with this one because uh i did work for bnsf for a couple years but i was a mechanical shop foreman so i didn't really work on these i just coordinated work on the locomotives and organized them and and assigned guys to work on them and made sure things were flowing smoothly so i am not the best technical expert on diesels i will say that first and foremost but i hopefully have enough preliminary level information for you guys that i can help you guys understand some of the nuances of how they work what we have before us here is one of my favorite locomotives we had come to the shop um this is the locomotive that my buddy jeff dubbed the war pumpkin because uh it had an engine fire and so the middle of the locomotive got cut out uh and replaced with the car body off of a decommissioned locomotive that was painted in the warbonnet colors but the rest of it is painted in the old pumpkin scheme so it's the war pumpkin the war pumpkin yeah we like we like having fun here anyways so this is a general electric dash 9 diesel locomotive from the 1990s one thing to note about american diesel locomotives is that there's primarily two manufacturers anymore being ge which is now ab tech and emd which is now progress rail which is actually caterpillar but getting beyond that i'm going to be using pictures from both of these locomotives to explain or both these manufacturers locomotives to explain a lot of these concepts but it's important to understand that most of my knowledge and understanding comes from the emd specific stuff so a lot of what we're going to be talking about is more applicable to an emd locomotive rather than a ge it just depends on what pictures i had available from my my time here so here's your typical general electric locomotive dash nine and here is a typical older emd locomotive this is a gp38 they also had bigger six axle variants as well but this is pretty common for what we saw at my shop let's get to it what is level one in terms of understanding how a diesel locomotive works while level one is understanding that a diesel locomotive does not work like your diesel pickup truck does not at all the diesel engine which lives inside here actually only exists to run a giant alternator that's up here or generator in some cases but we'll get into that nuance later and then that giant alternator can then supply electrical current to the traction motors that are in the trucks so the diesel locomotive is really a diesel electric locomotive where the actual propulsion is powered by electric motors which is supplied by that giant alternator and so let's take a look at some of that stuff inside the body we have our diesel engine and the diesel engine power is a giant main alternator and for scale here is one of the main alts um and this is on the floor at the kansas city locomotive shop here's a locomotive and this is how big the alternator is the alternator in your car is maybe both of your fists put together so um this one's a good you know six foot tall so uh it's a bit of a small alternator right and then those power traction motors and so this is a wheel set with the motor built into it we call it a combo in the industry and we could take another look of one being lifted by a crane but this assembly here is the whole actual electric motor and it's got a gear case that then runs and drives the actual axle that the wheel set is attached to and so in our level one we have big diesel engine inside the body the power's a big alternator inside the body it really is a big alternator and then that then powers our traction motors and that is how our locomotive can move it is a diesel engine at the end of the day or diesel locomotive right so let's learn a little bit more about the engine and for that we're going to talk specifically about the emd style engines for this portion here and this is going to be our level 2. here is a brilliant demonstrator that bnsf has and this is a diesel engine that's been cut down so you have the one end of it and the other end of it and they took all the middle bits out because normally these engines are typically a a 16 cylinder v16 so you'd have six more cylinders in between these two guys here that you can see but those have been omitted so that they can teach the important bits on the back end and the front end and you can actually see there's a there's a ge one over here you can see they put their logo on it they're quite different in design between emd and ge the primary difference is that emd is two-stroke and ge is four-stroke and what that means if you're unfamiliar with car engines or or engine design in general is that there's two strokes to complete the whole cycle down up would complete it whereas if you have a four-stroke engine like this guy you have to go down up down up and then you restart your cycle and it's a little easier to see if we take a look at one of the power assemblies so this is an emd power assembly that has been cut out cut open so you can kind of see what it is you have a cylinder head with all of the cams and rockers on top and you have the liner or the actual cylinder walls that are water cooled and then your piston is inside with connecting rod that goes down and so this is kind of what your engine is actually made of or these individual power assemblies or power packs or some of the old heads would call them an hlp a headliner piston and you can actually replace this as a whole unit in the engine so the block in the engine is actually not that big of a deal this whole structure here is just a case for those so rather than changing engines when time comes they actually just change the power assemblies out typically sometimes you know after a lot of awareness and going for like a really big overhaul yes they'd change the whole block and everything too but typically we would have failures of one or a couple power assemblies and you'd do them as sets a two um or you'd re-power pack half the engine or the whole engine but anyways you have two strokes in this this is an emd power assembly so what you have is when the piston gets all the way down you have your intake air running through these ports like this and then it gets compressed all the way up to the top when the piston gets all the way up to the top it actually compression ignites there's no spark plug there's no glow plug uh just the physical compression of the fuel that gets squirted in uh from the injector on top plus the air is enough to make it detonate and then send the piston down and under a power stroke and then again you get an intake and as it squeezes back up there's actually exhaust valves on top that open so that the fresh air helps scavenge out the exhaust as it goes in one stroke so that's why two strokes are less clean or less efficient whereas with a four stroke you have an individual intake you have intake valves on top you have an individual open valve you let the intake come in you then compress the intake then you have a power stroke and then you exhaust that out all separately so your exhaust is separate from your air intake but in the two-stroke it's done in the same stroke but two strokes if you've got a lawnmower or you've got a weed whack or something around the house uh you should know that your two-stroke engines will run for freaking ever they are pretty bulletproof and that is certainly the case with these emd diesel engines because they really haven't changed the design much since the 1930s at least as far as the engine goes yes they've upped the cylinder sizes over the years and they've added better control and all that but this concept set up like this has pretty much been the same concept for the better part of 70 or 80 years which is really impressive so we kind of have an understanding of our power assembly so how does it sit in there that power assembly from the picture sits in here at an angle comes you know it comes up to about here and then it goes down and connects down to your crank down below and so this is called uh up top you have the top deck cover which when you open it you get to see the tops of these cylinders so if we take a look at that this is up close unfortunately a lot of my pictures were trying to find actual issues with the locomotives and documenting them so this particular locomotive had a fault with the engine block where the uh the slot that the power assembly actually slid into was cracked and it was causing problems so we had to document the pictures but you can see this is the cylinder head and it's held in by this which is called the crab and then the crab studs and uh and some giant nuts on there but those hold the power assemblies in there's one on either side and then you've got your exhaust valves here there's four of them run out of picture of course here and then your injector linkage right here and your injectors in the middle and that's actually what puts the diesel fuel in and the fuel comes through this kind of copper looking pipe so that's all up at the top deck of the locomotive and here's a better picture of the the other end of it with the uh the rollers here this is a really pitted cam that needed to get replaced but you have your cam lobes on your cam shaft that actuate the rockers and rollers and the the shape of these actually determines when the exhaust valves open um and then also when the injector does its thing and so that is all within the top deck cover up here so you open this guy up and you'd see all that stuff down in there well what's the rest of this we got some big like manholes and all that well this is called the air box this is where that lower end of that power assembly sits so you can see we have all the little ports there for our intake air those ports sit down in here where we have positive air pressure that lives in here so that we pressurize the air so that it will intake and it force the exhaust out natively as the pistons do their thing and then below that is the crankcase where the crankshaft lives so the crankshaft is all the way down at the bottom it's co-linear with this this is an attachment off of the crankshaft here so your crankshaft lives through there your pistons and their connecting rods then connect to the crankshaft there and that's actually what makes the actual mechanical energy but the crank case is actually in a vacuum and it's and it's where all your oil ends up draining to and so that's kind of the overall geometry of your diesel engine you have your top deck you have your power assemblies that run through you have an air box here to allow air to come in and you have a crank case where your oil ends up and we can scavenge the oil out and you want your crank case to be in a vacuum so that you're not trying to force anything through the the pistons the uh the pistons actually doing their thing draws the vacuum in here and uh if you don't have vacuum in here it means that your piston rings aren't seating quite well and that can lead to a number of troubling issues including launching the power assemblies at the top of the block which you don't like you don't want to do that but that is a really basic overlook at the geometry of the engine you have top deck air box crank case you've got cam shafts with the cams and the cam lobes up in the top deck you've got your crankshaft down bottom that your pistons actually connect to now i'm gonna pull a bit of heresy and this is the piston arrangement from a ge not an emd but it'll show you how it works so you have one bank of pistons on one side the other bank on the other side and on the ge's you have a master connecting rod that is that has the bearing and everything put together on it and then you have the articulating rod that is pinned into that they actually share a central bearing surface the emds are pretty much the same in the fact that they share their bearing on the crankshaft but you have what's called the fork and what's the knife so you have one connecting rod that has half then the other connecting rod that has half of the actual bearing and then there's a set of bolts that basically run together to hold it together on the bearing surface whereas the ge is all pretty much one section that then gets the other piston connecting rod pinned to it so slight difference in manufacturing there uh but the point is it's not like a car where each connecting rod connects to its own bearing on the crankshaft they actually share sets so in the case of ge they label them left and right and then their position one two three four five six seven eight and the emds they label them one through sixteen and so you have pairs that you know number one and number nine are next to each other the pistons share their bearing on the crankshaft so that was a quick crash course at a level two what is a diesel engine in a diesel locomotive look like this is already kind of getting quite complicated even at level two but hey we're a more complicated machine with a diesel locomotive than we were with a steam locomotive so uh feel free to ask any questions in the comments and we'll see if we can't clarify and hopefully uh like in the other videos some of you experts that really worked on this stuff and really done it can come in and support what i'm saying and or correct me but earlier in this step we talked about the air box having positive pressure so how do we get that that's a very important part for the locomotive well there's a couple different styles but we have to have forced air and so the early amd locomotives had what are called roots blowers which they look like this so a roots blower is basically an early way to force more air into something this is a lot bigger than the ones that you can put on your muscle car these are quite large for a diesel engine of this size you got to remember that even the early emd engine was 567 cubic inches per cylinder and you had 16 of them so you need quite a bit of air but uh those blowers go up here on the engine so you could see the engine was as tall as it was this is just the very top this is where the blower goes and i always thought this picture was funny we were replacing a roots blower in 2019 you know why are we replacing blowers on it on a locomotive when they've gone to turbos at this point but anyways uh they take intake air and it compresses it basically in an early mechanical fashion and sends it down into the air box there and you can see the actual gear train in here from the engine that then runs those roots blowers i'm sure someone out there has done a better animation for how blower works but you basically have two overlapping circles and you've got blades that kind of interlace and then as the air comes in it gets forced through those blades and comes out at higher pressure and that's a that's a pretty poor explanation but um luckily if you google anything about blowers you should be able to find something pretty easily if you want to know more in depth on that but we're trying to focus on the locomotive sides of things here so i said that they upgraded to turbos well most engines these days are turbos there still are plenty of roots blown engines your early gp38s were all roots blown but a lot of them got converted to turbos and a lot of them have turbos and this is a turbo cutaway from a ge engine rather than mechanically driving a set of blades that compresses the air you take the exhaust gas and you spin a big fan that then can compress the intake and on the ge it's just free floating the exhaust gas does it all but one of the neat things about the emd locomotives is that the turbo is actually clutch driven and what does that mean well that means that they still do mechanically drive the turbo through and it's highly geared so that the turbo spins 18 times faster than the engine does and because of that because it takes a long time to build up the exhaust pressure to drive the turbos the emds actually load up and start moving a lot faster than the ge's do because they get more instantaneous response with the clutch driven system because as soon as the engine speeds up boom you get more inlet pressure so it's able to work harder faster whereas with ge you have to speed the engine up start building up the back pressure of the exhaust and then you can start to spin the turbo harder so they're a little bit slower on the draw than the emds are and the emds are clutch driven and i say they're clutch driven because once you get to like notch six i believe that's when you get enough exhaust gas pressure to pop the turbo off the clutch and let the exhaust gas spin it exclusively because these engines run at a really slow rpm uh it's kind of impressive how slow they run the fastest speed on most of these emd diesel engines is only 900 rpm so when you're notch 8 your throttle is wide open the engine is doing less than most modern car idle speeds and that's just because of how big the pistons are right when you're running slow you're only getting so much rpm it takes a lot of exhaust gas pressure to build things up and so the roots blower or the turbo depending on what the kind of locomotive has supplies that fresh air to the air box from the turbo's end in the case the emd that ends up supplying your higher pressure air for the pistons so we were talking about throttle notches let's let's get back to things that we kind of know in our level four here and we're going to talk about the cab controls things that you actually experience as an engineer okay so here is a picture of a typical control stand on an emd diesel locomotive some of the ges looks similar and and every railroad has slightly different flavors of these and you know but this is this has your typical controls so one of the nice things about diesel locomotives is that they're much more ergonomic than a lot of the steam locomotives are everything's kind of at your fingertips right in front of you and uh it looks like it's a lot to look at but it's not that much you have your reverser right here and that's actually your key for the locomotive the reverser handle is removable and you need to have one you shove the handle in and then you're allowed to throw the reverser to let the locomotive operate if you push it forwards you select forward you push it backwards you select reverse pretty exciting next we have the throttle which is set to idle it's got a little readout where it is right now and as you bring it this way you start notching it up and it has defined notches you only have idle and then eight power notches so notch one through eight and you can click them up individually as you go down you also have the dynamic breaking handle which we will talk about uh more in our next level but this is a different kind of break than our air brakes that we talked about in my last video and it again also has eight notches once you start setting it up over here we have 26l equipped air brakes on this particular locomotive which we talked about a bunch in my last tutorial video air brakes 101 10 levels of air brake understanding if you haven't checked that out i hope you do and you can see kind of how this works from the fundamental train side but you have your automatic brake handle on top and you have your independent brake handle down on bottom and this is 26l style which is the ubiquitous kind of came around in the late 50s you know most locomotives had it until they got computer control there up here we have the locomotive voice radio so this is where you pick what radio channel who you're talking to and there's typically a handset that is sitting off to the side but you can hear things through that speaker as well here's where the fun is horn valve it's very loud you also have a separate bell valve but typically it's set up so that when you start blowing the horn the bell starts going off as well you have your gauges up here and these are the same as they were in the steam era you have your main reservoir on the red needle right here you can see it's about 140 psi and then you have your equalizing reservoir in white which we didn't even talk about in the air brake video but uh perhaps in another video we will you have your independent brake cylinder and you can see it's 72 the independent's set up all the way and this must be a single clasp locomotive set up 72 psi brake cylinders and then you have your brake pipe which follows what the equalizing reservoir does so that's the brake pipe set on the train and then this is a neat thing that we also didn't really talk about in the air brake video and not all locomotives are equipped with this and no steam engine was to my knowledge but this is your air flow meter indicator so you can see how much air is flowing down the brake pipe so you can see as you're taking a set just how much air is actually flowing i've never had the privilege to operate with one of these so i don't necessarily understand a hundred percent what you do with one of these but the nice thing is it shows you what the flow through the brake pipe is i believe while you're applying and releasing so you can see at what points you know what what the rest of your trains going to be doing and it helps you guide your air brake sets should you use them we also have a number of controls and switches which vary per locomotive and this locomotive appears to have the isolation run switches and headlight switches all located on the control stand some of them have them on the back wall some of them have them here so every locomotive is different this particular one has what's called safety control reset which i would assume is the flavor of alerter which there is a device built into these locomotives where if the power is on if you have the throttle on and you don't have any air brakes set it knows and if you don't move any handles or confirm by thwacking the stick or pressing a button in some cases that you're still awake and alive it starts beeping at you which is very obnoxious so make sure you're not falling asleep at the wheel all that good stuff and if you don't acknowledge it it'll put you in a penalty break application and you'd have to move your automatic to handle off to let it recover but you also have some indications for wheel slip for sand on the sand control as well and then all of these different switches so we could get into the specifics of every single one but it's different per locomotive in a lot of cases and and per railroad in some cases as well so perhaps for another video but this is kind of a basic look at your control stand and what you see in an older locomotive the more modern ones either some of them have this sideways setup still some of them have the desktop controls but typically you have ptc screens as well and you also have computer controlled air brake and computer controlled gauges rather than some of the uh the old pneumatic stuff so slight differences but this is a basic look at what the control stand looks like and does in a diesel locomotive so when i talked about some locomotives having the controls on the back panel this is the case of most of the locomotives i dealt with at bnsf where you have what's called the enunciator panel and this is where you have a number of different controls and indications so in the case of this locomotive we have our headlight setup switch this is saying okay you know uh i'm gonna consist of multiple locomotives what do the headlights need to do because if your single unit intermediate unit you want to uh you want to have your headlights control one way but if you are the controlling locomotive you want to have you know total control your headlights when you put it on full bright forwards you want to make sure that your headlights come on but the engine behind you doesn't have his headlights come on so you have to set these per consist you have your isolation switch which allows you to be either in start stop or isolate the locomotive for when you're sitting or in run ready to do things and ready to operate you have a very important thing called the emergency fuel cut off uh should you have issues or you need to shut down the locomotive you gotta press this button here your number board lights are here lights underneath the platform steps lots of little switches there this is your traction motor cutout switch so if you have a failure of traction motors this particular locomotive allows you to cut out one and six two and four or three and five all together so if you have an issue with three and five for whatever reason you could cut them out and continue running if you needed to and that typically comes from a ground relay issue where you start getting a hey you're dumping like hundreds and hundreds of amps straight to ground something electrically has gone wrong and uh you're not able to use the motor for power anymore okay well then we come over here and we cut one of those motors out until we get this to go away and then we can make it back home so that the locomotive can be fixed hopefully there's a number of other indications up here and it depends on the type of locomotive and exactly what they're equipped with like the older ones had things related to the engine's governor which we'll talk to later uh the emds have a turbo lube pump indication if they're turbo powered so you know all sorts of fun stuff that you know are something for another video or perhaps another level but this is kind of what a back panel on a lot of these locomotives does look like earlier when we were looking at our control stand we were talking about dynamic braking and the dynamic brake handle and how it works so for the engineer the dynamic brake handle set to off throttle set to idle if the throttle is set to idle and you've got the reverser thrown you can grab the dynamic brake handle and you can move it to setup to say hey i'm going to go into dynamic braking and then you have eight notches of dynamic braking again just like your throttle does but we keep saying dynamic braking how does it work fundamentally how did it what does it actually do well let's take a look back at our picture of the 2096 at the roundhouse this is an emd gp 38-2 and it's got dynamic braking equipped dynamic braking is rather than using our electric motors as motors we use them as generators so what does that mean well normally a motor when you apply electrical current to it then creates a mechanical rotation which is how we have you know we take our alternator we dump the current into the traction motors boom choo choo gets to go very exciting in the case of dynamic braking we apply a resistive load to the motors we connect a load to them instead rather than supplying current we're asking for current and so we have what is called the grids up here and um for lack of a better explanation this is just a giant toaster on top of your locomotive this is just a bunch of huge resistors that are just designed to soak up current and dissipate heat so you connect the grids to the motors and by using the dynamic braking handle you can say how much current that you want these motors to actually generate as you notch up through the dynamics and so as you are generating more and more current it takes energy to do that and so you remove some of the mechanical energy regenerative braking is essentially what it is you start to remove the mechanical energy you turn it into electrical energy and then you send it up to the grids to be cooked off and then there is a fan that keeps the grids cooled off and blows it out to the sky but why are we doing that we we have batteries on the locomotive and you know what like the teslas and the priuses use that to charge their batteries why don't locomotives do that well if you're in notch eight dynamics you can be pulling close to or in some cases in excess of a thousand amps when you're in full dynamic braking and that's a lot that is many amps uh one amp is enough to guarantee kill you if it goes across your heart almost in every case just about and so this is just a casual thousand which is a lot but you got to remember that like your your phone charger charges at like maybe a half amp or a quarter amp at most and that's so that you don't kill the battery because the faster you charge a battery the more likely you are to basically ruin the chemistry inside of the battery um and so in order to use that thousand amps you need a lot of batteries and you need a lot of batteries with a significant capacity wabtec has started to develop a new battery-powered locomotive called the bel which we won't get into too much but it is the size of the war pumpkin but full car body so it's extra wide and it is just jam-packed with batteries and that is how many batteries they need to be able to take the amperage output of dynamic braking from the motors so yeah that's why they don't do it is because choo choo heavy and choo choo need lots of power to stop okay so we talked a little bit here in level five about dynamic braking and how that works earlier we talked about another electric thing we talked about that big main alternator well why why is it an alternator a lot of people say that it's a generator well let's talk into level six let's talk a little bit about how the electrical system actually works and this is going to be like the cutest little toes in the pool explanation because uh i'm not a locomotive electrician i'm thinking about asking one of my former locomotive electricians from bnsf and see if you wouldn't mind uh schooling me a little bit on this or maybe doing a a collab episode where we could talk about this in more detail but it's a really nuanced complicated thing that makes locomotives go so i'm just to give you the basic overview from an emd perspective early emds did have a big generator instead of an alternator but almost all of them in emd or ge nowadays has a big alternator okay so why an alternator why is it that instead of a generator well there's a lot of efficiency things to be said and you're able to scale more power out of a big alternator than a big generator for one but basically the way that it works is that rather than a generator just taking a mechanical energy so spinning engine shaft and then turning that into electrical energy an alternator can take that same mechanical energy plus an excitation voltage so you have to send electricity to an alternator plus the mechanical energy to get a lot more energy basically is kind of how this works you can get a more efficient power output and when you're talking about needing to output something like up to 1200 amps out of one of these things you really kind of need the efficiency you can get the emds actually have a separate generator that supplies the excitation voltage to the alternator so it's kind of the situation of you've got a you've got the generator for the alternator it's kind of like you've got the engine to start the engine kind of thing if you've ever looked at one of these emds and you've seen this this this bump out on the side of the frame we call it the bubble and that's actually where your air ducting for the auxiliary generator is located so what is the auxiliary generator well we've got an ancient picture of one this is your generator it attaches to part of the drivetrain drive shaft in the engine via lots of gearing and all that it's not just directly connected but anyways this is connected to the drivetrain and then you create an electrical signal you create voltage that runs out of this thing and then that then runs into the big alternator that's located about the same spot you send that electrical voltage in to the alternator then the giant alternator can really take that and make it the high power that these locomotives actually need in the high voltage and high amount of amperage that the locomotive actually needs to move the ges like this kind the 7811 or our favorite war pumpkin they are slightly different in that they do not have the oxygen they are self-exciting they have what's called the companion alternator within the main alternator which then provides the electrical signal for the alternator to run off of and i believe on the ges that that is supplied by the locomotives batteries somebody who knows the the ins and outs can probably correct me on that but that's the nuance difference uh between emd ge on at least on that piece but that's a really really basic look at what the main alt does and how you actually get the electricity and as you select forward or reverse it determines what polarity the voltage is going to be going to the motors whether you're making the motor spin forward or reverse right as you increase the throttle notches it notches up the engine which spins the alternator faster which means you get more electricity which means the locomotive pulls harder so there's a lot of little steps between this and we're even going to get more in depth than that uh in another couple levels here but that's uh that's kind of your basic look at some of the electrical propulsion side of this and that is our level six now in level seven we wanna talk about some of the support systems on these engines because you can't just have diesel engine in it and it runs just fine it's not like your car where you have you know just one radiator and one little water pump and and then that's great and you keep oiling it and uh the car is happy right it's a lot bigger than that and a lot more nuance than that so the next three levels seven through nine are all going to be about the support systems level seven is gonna be talking about the start of how some of those support systems are configured and some important terms and other connections that we have we have the front and back end of an engine for an emd style diesel locomotive the front is this end with all this fun business stuff that we're gonna talk about in the next two levels and then the back is the end with the turbo or the blowers where the main alternator is located so you go that way you go electrical you come this way you go mechanical look at that it's very fun you also have on the emds a shaft driven air compressor that is then attached to the crankshaft down this way so as we come this way from the front end of the engine which is actually in the back end of the locomotive front engine is actually back of the locomotive so if we look at rgp 38 the water pumps and oil pumps and everything are back here our air compressor is back all the way over here and then our main alt is up front and our exhaust stack is up here whereas of course because the manufacturer's off to be different ge has it the other way around where the exhaust stack is in the back and the main alt is attached on the other end of the engine so just gotta make it just as challenging as physically possible but let's take a look back in the gp 38's case let's walk back towards that air compressor and take a look at that a little bit and uh knowing this you gotta remember that i mostly took pictures of stuff that was broken for documentation so here's your air compressor um this one puked most of its guts out but you can see the uh the shaft runs up here you can see where it bolts in and there's plenty of fun stuff in here but here this is your air compressor it's got these big cylinders in here that actually compress air so it's a a rotating shaft based engine basically it's an air engine that squeezes air as the pistons move up and down and it's got a lot of water cooling that runs through it that we'll talk about in another level but your air compressor is what's attached in the in the back there and you know what happens when you break all the bits on the inside well typically also break the bits on the outside here's a here's an external view that air compressor pulled off of the locomotive and this is the shaft that connected to the engine and when the air compressor locked up something had to break and guess what it was the drive shaft and this is actually a brilliant look at a torsional ductile failure where it failed pretty much on the 45 degree line down the uh down the pipe that's like classically what they teach you in school which is kind of funny to to see in the field something actually breaking that way anyways now so we talked a little bit about the air compressor and the back end of the locomotive which is the front end of the engine what do we have more on the other side how do we connect up to that main alternator so here's a picture of the locomotive the uh the rear of the engine with all of the stuff removed it had a bad day the turbo's gone the main alts has been shoved back and most of the gear trains been removed this was a locomotive that was stuck at the shop for eons because it had a massive failure at this at this back the rear gear train here so what what do we have that is then attached to that well we have a flywheel a ring gear and a flex plate this big metal honking guy with the holes drilled in it is the flywheel and it's been precision balanced and all that and it's got little ticks on it that are actually the degrees of rotation because you need to know you know at what degree is what cylinder all the way up or all the way down top dead center or bottom dead center for a number of different reasons we have a ring gear which is something the emds have that the ges don't because the emds actually have starter motors that start by grabbing that ring gear so this is one starter they typically have two this one was removed again we were doing some maintenance but uh when you send electrical power to this it starts to spin the ring gear and then that actually is what starts the engine up whereas the ges are smart and they just use their own alternator to start themselves but sorry md anyways so this is your engine side over here and your alternator side is over here the starters grab this ring gear start things in motion and the ring gear and flywheel are attached to each other uh but then there is also the flex plate and that's what's broken right in here the flex plate is a flexible coupling between the engine and alternator such that if something locks up for some reason or there's a huge issue like that uh it's not translated between the engine and the alternator so yeah you can see that either you know if something locks up in the alts the engine can still spin and provide support if something locks up in the engine it doesn't immediately ko the alternator because it'll break the flex plate like this one and uh lordy that was a pain in the butt any time those came in that was always quite a lot of work and the machinists that could actually make it happen and replace one of those yeah they they knew what the hell they were doing those are good guys but here's a ring gear on a pallet uh as it split up this is a three-piece one some some of them were single piece which made them incredibly challenging to put in but the three-piece ones were easier if you had teeth stripped off of the ring gear for any reason you know starter problems because that was probably the most common problem we ran into is failure of the starter motors and all that anyways that's kind of looking at the geometry around our engine a little bit so let's kind of recap a little through that while we're here so in our engine we have the front of the engine which is at the rear of the locomotive with a shaft driven air compressor off the back and then at the rear of the engine we have a connection with a flywheel flex plate and ring gear that connects us to our main alternator that's your overall geometry of of the system of locomotive put together right there the next levels we need to talk about the other little support systems that go in with that before we go down that rabbit hole we should do a quick recap of all the systems because this has been going on for quite a bit now at this point right so let's do a quick talk through so we have a diesel locomotive it is actually a diesel engine that powers a giant electric alternator that then runs electric motors to drive it's not a directly mechanical diesel vehicle like a diesel truck is or any other diesel driven car or anything like that that's your level one your level two is that we have a diesel engine it's got a top deck it's got power assemblies that live within it an air box and then a crank case and of course that is the emd flavor the ges are different maybe another video for those perhaps if if folks are interested and the air box supplies our intake air to our power assemblies and it's a two-stroke system right but so how do we get that air well that's where we have roots blowers or that's why we have turbos depending on the age of the locomotive but both supply air input and remember the cool thing about emds is that the turbos are driven by a clutch big clutch on that side of the engine so that in lower speeds and lower notches we can start loading really quick because we can get that turbo giving us that high pressure air as fast as it can we have a control stand that lets us operate the locomotive with reverser throttle dynamic brake and our air brakes amongst a number of different things and we have all sorts of fun stuff to tell us what the locomotive is doing we have dynamic braking where we use our motors as generators instead and we take that electricity that they generate and dump it up through grids which then vent off as heat and that generation of power actually slows down the train pretty significantly level six was talking about that main alternator again and how it needs to have an auxiliary generator or some sort of source of electricity so that it can supply the higher power electricity to the electric motors and how the throttle and reverser achieve that and make us actually drive the locomotive and level seven was talking about the geometry of the engine and the things attached to it so we have the front of the engine which is at the back of the locomotive the shaft driven air compressor then we have the back of the engine at the front of the locomotive with flywheel flex plate and ring gear that then connects us to our main alternator and we have starters attached to it and then start the locomotive unless we're smart like ge and it can start itself so level eight is going to be talking all about water it's not coolant it's not antifreeze it's just water diesel locomotives just use water that is treated with something called borate which just basically makes it die green and you can see if it leaks and it also is a bit of a rust inhibitor but it's not antifreeze or anything like that and so what happens if the engine gets cold you may ask well there's actually little valves built into the system called guru valves and the guru valve opens up if you get to less than 40 degrees fahrenheit and so as soon as you get less than that the guru opens and it drains all the water out the system and you've got green everywhere and it's total pain to deal with one of the fun things is like the the shops in the north on the bnsf system would typically uh they would they would shim the gurus closed with pennies they'd stick a little penny in there and they'd rip the diesel engine open and pray they could get it started and up to temp uh before they had a problem then they'd have to pull the pennies out or if you forgot to pull the penny out that's how you freeze an engine block but that's one of the big issues that they deal with it the shops in like minneapolis and and haver montanas getting locomotives out the door and starting them as soon as they could when it was in the winter so that the uh the engines didn't have any issues but the water system has two pumps on an emd a left side and a right side and at least in the case of the emds they supply water down through the air box through a big pipe and then that water then flows through the power assemblies you've got a water jacket inlet and outlet on these that lets water run through and cool the engine built in so when you remove and replace one of these power assemblies you actually need to undo those water connections and you have to have the water drained out of the locomotive which always adds to the fun the water also needs to run through and pull the air compressor and you can see that you've got these nice hoses that actually are the water hoses through the air compressor to keep it cooled because the air compressor generates a lot of heat as well but how do we keep the water cool it's pretty simple and it's just like your car in that case except for where it's located we have big radiators up in the rear of the locomotive for both emd and ge they're big and up here and then you have radiator fans which live up top and actually exhausted out this particular locomotive the gp38 only has two some of them have three and they are stepped up to control exactly what the temperature the water needs to be so if the water temps really high you kick on all the fans if it's below operating spec you'll you won't have any fans on but if it you know if it's in somewhere in between you might have one fan come on and all that to get fresh air flowing across the radiators and ensure that you can cool the water back down before it comes back into the water pumps here and the inlets on those water pumps are what's missing right here in this diagram so you come from straight from the radiators boom you go back through there and some general electric locomotives actually have what's called split cooling where the water doesn't run through the radiators all the time the water will cycle and back cycle through the engine and through the water pumps uh or water pump actually on a ge and it'll only get diverted through a special butterfly valve if the temperature is uh high enough that the coolant needs to be cooled t he because the ges tend to only have one big radiator fan so they can't modulate speed like the emds do they modulate the coolant instead to regulate temperature so that's a fair bit about the water and cooling system on these locomotives there's still of course more nuance to it but that's that's a good 101 level so that's gonna be our level eight so what about level nine level nine is going to be talking about the oil system and how oil moves throughout the engine and we're gonna be specific to amd on this one so your engine oil ends up in the crankcase down in the bottom when you start up with it the engine oil is then scavenged by the scavenging oil pump or the main sump pump depending on what terminology you like to use and it gets sent out of a pipe that is missing out of this picture right here and it goes through a drum of oil filters and there's a couple different styles of that here is an old santa fe style with individual filter elements though most of the locomotives later got a big barrel style element where all the filters lived in one place after that it then goes through the lube oil cooler it's a basically heat exchanger with the water system as the water is coming back to the pumps that's the last thing it runs through is the lube oil cooler and then from the lube oil cooler it goes to the ice cream box there's ice cream on a diesel locomotive didn't you know that that is the the old school slang term for this right here because it looks like a 1950s bicycle with an ice cream tub on the front to sell ice cream via bicycle it's a thing that doesn't really exist anymore but you go to most of the railroad machine shops they'll still be calling this the ice cream box uh the technical name is the lube oil strainer there's several strainer elements in there and i say strainer because they're not filters they're like eighth of an inch holes this catches the sockets of your machinists who are working on things before you end up sending the oil through through to the uh the pistons so just in case you drop your 10 mil uh it goes in here first and gets caught and from the lube oil strainer it goes into the piston cooling pump and the main lube pump and it this is kind of like a two in one style pump on these emds one sends a specific grouping of oil to be shot up through what are called p pipes into the power assemblies to lubricate the cylinder walls and then the other one goes to the main lube oil header that then ends up lubing up pretty much everything else the camshafts the crankshafts once the engine oil makes it all the way across the engine if it makes it through the main loop oil header without getting you know distributed and lubricating other various parts it'll end up going through the soak back filter the turbo filter right here and then it'll get sent through to the turbo but however when the engine is not running because the turbo is mechanically connected and spins very quickly you have to pre-lubricate the turbo before you start a locomotive so as part of the start sequence you have a turbo lube pump down here that can take some of the oil from the crank case and send it up through the turbo lube filter into the turbo when the engine is not running but when the engine's running you primarily use the oil from the main lube pump that is then gone through that secondary filter before it goes to the turbo and lubricates everything there and then it ultimately all comes back down to the crankcase and starts over again again i mean all these things we're just getting our toes into the water and how they work we're not talking about component theory or torque specs or you know flow rates or temperatures or anything like that um but that's basically what goes on in uh in this section here so we've talked about these ancillary systems that support the diesel engine and how they operate in a little bit of detail and that's been our level you know seven eight nine now what's level ten hopefully some of you uh who know these things have seen this guy and have been shuddering at the fact that i haven't talked about it at all and that's why we're going to talk about it in level 10. this is the governor this is basically what tells the engine how fast it needs to run and then this is kind of the uh the brilliant and complicated thing of these early dc locomotives because this kind of early emd diesel locomotive is still mechanically fuel injected it has a mechanical rack that the governor adjusts so there's this this is the basically the throttle bar it's called the lathe shaft but when you grab this you can actually increase the engine speed by modulating what the governor does and it increases the amount of fuel being dumped into the diesel engine because the governor gets to tell the mechanical rack where all the fuel injectors are hey this is this is how much fuel i need you to run this is what you need to do you know squirt more in and then the engine will catch up on its rpms right afterwards and then the turbo catches up and you get cleaner burning as you rev up right now how does the governor tell the engine to do that well it's quite complicated and i think you could probably have a whole class on how a governor works and most of the machinists that i had at the roundhouse they knew the idea of the governor that and that how it worked but uh the specifics of everything inside i mean it's a black box system for us which means we put this part on and it does what we need it to there were a couple guys who were really really good who really actually knew the innards and could go through them but we didn't tend to do that so um just replaced him at component level but so how does the governor work well of course it's pretty complicated and there's a special relationship with the governor the throttle in the cab the load regulator and the main alternator so you have these four pieces so we have our main alt big spinny guy right we have our load regulator small guy that is basically has a dial that says how much load is being applied it can indicate that and then you have your throttle valve or knife i'm so used to steam engines you have your throttle control and so as you advance the throttle control and you bring the throttle forward in the cab it opens different valves in the governor the a b c and d valves depending on what position and you get various combinations of those valves which tell the engine how fast it can run and so that begins to speed up the engine which speeds up the alternator which means that we can get more electricity out and we can load the traction motors harder so we can accelerate faster or pull harder so what if the engine can't meet the demand of the alternator because it's ultimately a demand based system i set the throttle here i want to have this much power going to my traction motors the alternator knows how hard it needs to work to generate that power and it has to be powered hard enough by the engine to make that work happen well if it can't for any reason the load regulator will back off and it'll decrease and i can't i genuinely can't remember which way it rotates that there's an important thing in troubleshooting about it'd be clocked one way or another depending on if it was you know running full or not all my former employees at the nsf are gonna tell me that uh they're disappointed in me for not remembering that but i've forgotten more about this stuff than i ever learned i think point is the load regulator backs off which then tells the governor and the engine like hey it's okay we're gonna we're gonna load less than what the throttle is allowed to let you try and catch up and then it'll try and amp things back up again but you have this nuanced relationship of the throttle telling the governor what to do but it has to mesh between what the electric system is able to do so you have this dynamic system of sometimes okay the governor can't give us the engine speed we need or there's a problem with the fuel rack and it doesn't rev up fast enough so we lose the load to the traction motors and the alternator has to cool off so we're not getting everything we need but then as the engine can pick up speed or as the problem gets resolved it comes back to you know full power and we can get back to where we are but that way you know you never end up like bogging down or stalling the engine really and i'm sure judging on some of the comments on my other videos there are going to be some folks who are going to know this so much better than i do that i'm going to pin probably the top comment on what it is because this is a very confusing and nuanced relationship between the alternator the load regulator and the governor which is why they don't have them anymore the more modern locomotives don't have governors they don't have mechanical racks they're electronically fuel-injected and it's all computer control now so this this is the antiquated system so um and it's quite complicated but quite interesting and it works pretty well except for when it doesn't and it's usually because the governor is a piece of junk which uh that was our experience at least at bnsf so that's a real quick look at a level 10 talking about the way that the engine the alternator and governor and load regulator end up working together because the governor is your guy that sets engine rpm your max engine rpm is set from what the governor says it could be and then it modulates it based on what those throttle valves are it modulates the speed accordingly if it can let's do a quick recap before we finish up we have diesel locomotives they're actually diesel electric they're not just straight diesel we have an engine which then powers an alternator and the alternator then powers traction motors and traction motors make our train go the engine is built out of power assemblies hlps with an air box crank case and then top deck for us to inspect whatever is going on the air box needs positive pressure to ensure that our engine can do what it needs to do so the locomotives are equipped with roots blowers or they are equipped with turbos most of them turbos these days to supply the air we need that way we can get the power we want and we get the power we want by using the cab controls we have in our control stand with our reverser our throttle our dynamic brake our air brakes and all of that we also get special indications from these that let us know what the condition of the locomotive is and with our dynamic braking we take the traction motors we talked about and we turn them into generators and we take this excess electrical current dump it off into the atmosphere's heat through a big series of resistors called grids and that resultant electrical production slows down our train uh electromechanically regenerator of braking but we don't save it inside of our locomotive we have an alternator and the alternator needs an energy source and in the case of an emd it is the auxiliary generator that lives in the bubble right here the oxygen provides the excitement for the main alternator so that the main alternator can then supply electricity to our different traction motors our engine has a number of things connected to it as support systems we have an air compressor that is shaft connected in the case of an emd off of the front of the engine rear of the locomotive and then on the other side which is the back of the engine or the front of the locomotive we have a flywheel flex plate and ring gear that connects the engine to the main alternator which has starter motors on it that allow us to start the diesel engine we also have a complex water system that uses water rather than coolant with gurus for freeze protection radiators radiator fans and we have typically multiple water pumps that run through and send water through the jackets of our power assemblies to ensure that everything is running at the correct temperature we also have a complex oil system on the locomotive where we take oil from the crank case run it through a main pump to scavenge the oil we run it through a filter barrel we run it through a cooling unit we strain off any bigger bits like accidentally drop sockets and bolts and then we send it through all the different various parts of the engine in order to keep things from wearing out and also to ensure that the temperature is correct in the engine and lastly we have a governor on these mechanically operated diesel locomotives and the governor load regulator and the alternator working in combination with our throttle assembly allow us to pick what speed we want the locomotive to run at and how hard we want it to load so that we can operate the train as we need to okay guys that was a ton of information and i'm sure that i made an error here there but that's a really good crash course 101 level this is how diesel locomotives work and it was really tough to find a way to describe some of this stuff with just pictures thankfully for this one i had a lot of good pictures but diesel locomotives aren't inherently as easy to mechanically understand as a steam engine which is what makes them interesting but it also makes them more challenging to explain so i hope you guys liked the video and i hope you guys learned some things and by all means for you experts out there who really work on this stuff please chime in i'd be more than happy to have discussions and correct the video if i got anything wrong particularly level 10 uh and and have further discussions on how these work but this should be a decent primer for someone who doesn't know how a diesel locomotive works hopefully now i have a decent idea an understanding of yeah there's a fair amount that goes into this and uh let me know if you guys would like the in-depth look with that with an electrician buddy of mine and i'll see if i can't uh i'll see if i can't convince him to do it so anyways guys thanks so much for watching i'm heiss make sure you like the video if you did subscribe to the channel click the little bell if you want to know when i'm posting content or going live so thanks for watching

Channel: Hyce

Views: 206,005

Keywords: EMD, GE, diesel locomotive, diesel, train, locomotive, 101, class, tutorial, teaching, how does a train work, how does a diesel locomotive work, diesel engine, engine, 645, 567, 710, 2 stroke, BNSF, trains, railroad, railway, classroom, school, education

Id: G7nqvjCbsv0

Length: 60min 19sec (3619 seconds)

Published: Mon Apr 11 2022