Railway Man Fear of unit failure was not and is not the problem. The problem is this: there are very service designs in the U.S. that economically favor a locomotive consist with 12,000 hp but only 300,000 lbs of continuous tractive effort, as opposed to a locomotive consist with 12,000 hp and 450,000 lbs. continuous tractive effort, or multiples thereof. The 6,000 hp locomotive has been a locomotive in search of purpose and need. If it had one, there would be a lot more incentive to solve their technical problems. RWM
Fear of unit failure was not and is not the problem. The problem is this: there are very service designs in the U.S. that economically favor a locomotive consist with 12,000 hp but only 300,000 lbs of continuous tractive effort, as opposed to a locomotive consist with 12,000 hp and 450,000 lbs. continuous tractive effort, or multiples thereof. The 6,000 hp locomotive has been a locomotive in search of purpose and need. If it had one, there would be a lot more incentive to solve their technical problems.
RWM
This is the insight I was looking for. This brief paragraph explains it all. Thanks, RWM, for lighting the little bulb in my brain.
Assuming that CSX practice is similar to Conrail's on the same territory, 12000 HP would be good for about 6900 tons of intermodal train between NJ and Chicago - a large but not atypical intermodal train for that route. Conrail would typically use 3 SD60s or C40s on intermodal trains of that size, so the attraction was going 2 for 3 on locomotives. Conrail was leary of new diesel engine designs, so opted for the 20-710 SD80. The lower HP made them better suited for the merchandise traffic on the Pittsburgh Line, but they wound up on the B&A - not a bad fit, but utilization was historically low there..
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
JayPotter bubbajustin6000 hp isn't enough for an intermodal train but 2 of them is way too mutch. To what intermodal trains are you referring? CSXT has routinely operated intermodal trains with two-unit AC6000CWs.
bubbajustin6000 hp isn't enough for an intermodal train but 2 of them is way too mutch.
To what intermodal trains are you referring? CSXT has routinely operated intermodal trains with two-unit AC6000CWs.
I knew I would run into this problem. I remember hering a locomotive expert, on The Ultamate Railroading DVD Series, say that for some instances 6000 hp isn't enough but on the outher hand 12000 hp is way too mutch. I'm sorry that I didn't specafy that. Although I think a 6000 hp locomotive is a better concept on paper. Although you have to admit that theay still look amazing going down the line. Also this unti is doubley tourboed, just a little tid bit there.
The road to to success is always under construction. _____________________________________________________________________________ When the going gets tough, the tough use duct tape.
Railway Man challenger3980 I think that another reason that you saw more Steam locomotives handling a train single handed is that the railroads had a lot wider variety of motive power to chose from in the steam era. Such as the Union Pacific, even many of their 1910's era 2-8-0's soldiered on right up to the end of steam in the late 50's Then they had 2-10-2's, 4-12-2's 2-8-8-2's 4-6-6-4 and 4-8-8-4's as well as others available. They matched the locomotive to the load and terrain to be crossed. If a 2-10-2 wasn't upt o the job, call out a Challenger, or Big Boy to handle the train. The later Challengers were designed and intended for a large part to work hand in hand with the Big Boys. The Challengers were built to handle a train that a Big Boy handled throught the Wasacht Mtns, take the same train through the lesser grades, and hand off that train off to a 2-10-2, or 4-12-2 in open country. A large part of this wide variety of power was due to the inability of Steam locomtives to MU, each Steam locomotive must have its own crew, so basically build a double Mountain (4-8-2) into a Big Boy, and you only need one crew to control the effective power of two locomotives. The diesel has the advantage of being able to consist together as many locomotives as needed, even DPU'd, and control all of them with one crew. Doug The economics is driven by labor costs, not locomotive costs, then and now. In the steam era, railways matched the tonnage to the steam locomotive, not the steam locomotive to the tonnage, and strove to reduce the labor costs more than anything else. The idea was to load the steam locomotive to the maximum it would just barely haul over the division. Alignments were laid out in an concerted effort to concentrate all the heavy grade into one short section and keep the grade everywhere else the same to avoid wasting horsepower. For example, a district might be engineered so that there were five 1% grades and one 2.2% grade, so that the road locomotive could just barely move its tonnage everywhere except one location, where it would need a helper. It would be very poor economic and engineering practice to lay out a line with four 1% grades, one 1.1% grade, and a 2.2% grade, because that would force either a second helper district on the 1.1% grade or a no helper district on the 1.1% and an undertonnaged train on the 1.0% grades. The railways then designed locomotives specifically for a given district, making them just big enough to haul the tonnage they wanted to move on the schedule they wanted to keep, for trains that would fit into the sidings, and on a schedule that would work with the forecasted tonnage and the passenger schedule. A stringline would be used to determine exactly how many trains would be run, at what speed, and where they'd meet, and with what tonnage, and various locomotive capacities compared iteratively to fit that stringline and tonnage chart, and arrive at a bottom-line number that delivered the highest cost-benefit ratio. Inputs into the formula included crew cost, estimated maintenance cost, fuel cost, track maintenance cost, car-hire cost, locomotive capital cost, and the cost of any required engineering improvements to accommodate a new locomotive or the longer, heavier trains it might haul. Locomotives were not purchased by looking at a catalog, but in a very detailed accounting and engineering exercise. I have a couple of old studies -- one I have from 1947 comparing the savings for F3s vs. 2-10-2s on the LA&SL runs to more than 250 pages of little type and tables, and today would probably cost $250,000 to produce. Many railways double-headed as a regular practice to reduce train crew costs as opposed to engine crew costs. Prior to the advent of dieselization and the cascading of newer steam locomotives into last-stand districts, the typical railway strove to assign a very limited number of types to a given engine district, in part to reduce maintenance expense by not scattering different types all over, but mostly because it made very little economic sense from an operational point of view. The ideal would be a district that had exactly one type for road freight and one for road passenger, for example, a heavy 2-8-2 and a heavy 4-6-2, and perhaps a third type such as a 2-8-8-2 or 2-10-2 if there was a helper grade in the district. The later smorgasboard of everything on places such as Sherman Hill was not done for operational reasons but for cash-flow reasons; the railway was seeking to extract the last dollar of value from still good engines before they became due for major overhauls. UP engine assignments in the 1930s before diesels appeared were highly simplified, with very little variation in most terminals for main-line drag freight and fast freight. From an operational perspective, it is a very poor practice to mix and match locomotive types and train speeds. Ideally every train moves at exactly the same speed, otherwise there are either overtakes (which use up an indordinate amount of main line capacity) or trains get to terminals too early and have nowhere to go, using up terminal capacity, or have to linger in terminals so that faster trains can run around them there. Mix-and-match train speeds use up crews inefficiently and create labor difficulties and costs because crews are being run-around and in some locals can time-slip for it. The idea is to add sections on the days that tonnage runs heavy and delete sections on the days it runs light, and every train looks alike, they only vary in number. If a district lies at the foot of another with higher train tonnages, then reduce tonnage on the inbounds at the terminal, and when enough accumulates, run another section. If a district lies at the foot of another with lighter train tonnages, it simply adds tonnage to fewer trains and avoids running light trains. The way to understand just about everything in railways is to start with the cost sheets, but that's pretty unexciting, I'll admit. But when you're a line manager with cost responsibility, you sweat every hour of overtime because if you have more than your peers, you will not be getting a bonus or promoted or left alone by the superintendent. RWM
challenger3980 I think that another reason that you saw more Steam locomotives handling a train single handed is that the railroads had a lot wider variety of motive power to chose from in the steam era. Such as the Union Pacific, even many of their 1910's era 2-8-0's soldiered on right up to the end of steam in the late 50's Then they had 2-10-2's, 4-12-2's 2-8-8-2's 4-6-6-4 and 4-8-8-4's as well as others available. They matched the locomotive to the load and terrain to be crossed. If a 2-10-2 wasn't upt o the job, call out a Challenger, or Big Boy to handle the train. The later Challengers were designed and intended for a large part to work hand in hand with the Big Boys. The Challengers were built to handle a train that a Big Boy handled throught the Wasacht Mtns, take the same train through the lesser grades, and hand off that train off to a 2-10-2, or 4-12-2 in open country. A large part of this wide variety of power was due to the inability of Steam locomtives to MU, each Steam locomotive must have its own crew, so basically build a double Mountain (4-8-2) into a Big Boy, and you only need one crew to control the effective power of two locomotives. The diesel has the advantage of being able to consist together as many locomotives as needed, even DPU'd, and control all of them with one crew. Doug
I think that another reason that you saw more Steam locomotives handling a train single handed is that the railroads had a lot wider variety of motive power to chose from in the steam era. Such as the Union Pacific, even many of their 1910's era 2-8-0's soldiered on right up to the end of steam in the late 50's Then they had 2-10-2's, 4-12-2's 2-8-8-2's 4-6-6-4 and 4-8-8-4's as well as others available. They matched the locomotive to the load and terrain to be crossed. If a 2-10-2 wasn't upt o the job, call out a Challenger, or Big Boy to handle the train.
The later Challengers were designed and intended for a large part to work hand in hand with the Big Boys. The Challengers were built to handle a train that a Big Boy handled throught the Wasacht Mtns, take the same train through the lesser grades, and hand off that train off to a 2-10-2, or 4-12-2 in open country. A large part of this wide variety of power was due to the inability of Steam locomtives to MU, each Steam locomotive must have its own crew, so basically build a double Mountain (4-8-2) into a Big Boy, and you only need one crew to control the effective power of two locomotives. The diesel has the advantage of being able to consist together as many locomotives as needed, even DPU'd, and control all of them with one crew.
Doug
The economics is driven by labor costs, not locomotive costs, then and now.
In the steam era, railways matched the tonnage to the steam locomotive, not the steam locomotive to the tonnage, and strove to reduce the labor costs more than anything else. The idea was to load the steam locomotive to the maximum it would just barely haul over the division. Alignments were laid out in an concerted effort to concentrate all the heavy grade into one short section and keep the grade everywhere else the same to avoid wasting horsepower. For example, a district might be engineered so that there were five 1% grades and one 2.2% grade, so that the road locomotive could just barely move its tonnage everywhere except one location, where it would need a helper. It would be very poor economic and engineering practice to lay out a line with four 1% grades, one 1.1% grade, and a 2.2% grade, because that would force either a second helper district on the 1.1% grade or a no helper district on the 1.1% and an undertonnaged train on the 1.0% grades.
The railways then designed locomotives specifically for a given district, making them just big enough to haul the tonnage they wanted to move on the schedule they wanted to keep, for trains that would fit into the sidings, and on a schedule that would work with the forecasted tonnage and the passenger schedule. A stringline would be used to determine exactly how many trains would be run, at what speed, and where they'd meet, and with what tonnage, and various locomotive capacities compared iteratively to fit that stringline and tonnage chart, and arrive at a bottom-line number that delivered the highest cost-benefit ratio. Inputs into the formula included crew cost, estimated maintenance cost, fuel cost, track maintenance cost, car-hire cost, locomotive capital cost, and the cost of any required engineering improvements to accommodate a new locomotive or the longer, heavier trains it might haul. Locomotives were not purchased by looking at a catalog, but in a very detailed accounting and engineering exercise. I have a couple of old studies -- one I have from 1947 comparing the savings for F3s vs. 2-10-2s on the LA&SL runs to more than 250 pages of little type and tables, and today would probably cost $250,000 to produce.
Many railways double-headed as a regular practice to reduce train crew costs as opposed to engine crew costs.
Prior to the advent of dieselization and the cascading of newer steam locomotives into last-stand districts, the typical railway strove to assign a very limited number of types to a given engine district, in part to reduce maintenance expense by not scattering different types all over, but mostly because it made very little economic sense from an operational point of view. The ideal would be a district that had exactly one type for road freight and one for road passenger, for example, a heavy 2-8-2 and a heavy 4-6-2, and perhaps a third type such as a 2-8-8-2 or 2-10-2 if there was a helper grade in the district. The later smorgasboard of everything on places such as Sherman Hill was not done for operational reasons but for cash-flow reasons; the railway was seeking to extract the last dollar of value from still good engines before they became due for major overhauls. UP engine assignments in the 1930s before diesels appeared were highly simplified, with very little variation in most terminals for main-line drag freight and fast freight.
From an operational perspective, it is a very poor practice to mix and match locomotive types and train speeds. Ideally every train moves at exactly the same speed, otherwise there are either overtakes (which use up an indordinate amount of main line capacity) or trains get to terminals too early and have nowhere to go, using up terminal capacity, or have to linger in terminals so that faster trains can run around them there. Mix-and-match train speeds use up crews inefficiently and create labor difficulties and costs because crews are being run-around and in some locals can time-slip for it. The idea is to add sections on the days that tonnage runs heavy and delete sections on the days it runs light, and every train looks alike, they only vary in number. If a district lies at the foot of another with higher train tonnages, then reduce tonnage on the inbounds at the terminal, and when enough accumulates, run another section. If a district lies at the foot of another with lighter train tonnages, it simply adds tonnage to fewer trains and avoids running light trains.
The way to understand just about everything in railways is to start with the cost sheets, but that's pretty unexciting, I'll admit. But when you're a line manager with cost responsibility, you sweat every hour of overtime because if you have more than your peers, you will not be getting a bonus or promoted or left alone by the superintendent.
RWM,
I respect your knowledge, and Appreciate your contributions to the forum. Your second full paragraph basically states what I was saying in a different manner.
To quote from, Union Pacific Steam, in color An Eastern District Pictorial, by Lloyd E. Stagner
Pg 57, Regarding the 2-8-8-0's of 1918, working Sherman Hill:
Capable of handling 2100 tons on the 1.55% grade, this equalized tonnage ratings all the way from Cheyenne to Ogden, with 2-10-2s, on the Wahsatch grade and 2-8-2s between Laramie-Evanston.
The info about the Late Challengers being designed to work hand in hand with the Big Boys was from a video interveiw with Steve Lee, head of the UP Steam Program.
My comment about handing off trains wasn't meant as in every ten miles, but at terminals, where it would be likely to see one particular type work east out of a terminal, and return, and another type work west and return. This would attempt to as you say reduce the number of types used out of any given terminal. A terminal such as Cheyenne though could see a large variety of types working through/out of it.
May your flanges always stay BETWEEN the rails
carnej1 Actually the SD90MAC and AC6000CW were marketed as 2 for 3 unit reduction ( 2 6,000HP units replacing three 4,000HP units). Most road freights in North America need more than 6,000 HP. However unit reliability was a problem as a train would lose half it's available tractive effort with a failure...
Actually the SD90MAC and AC6000CW were marketed as 2 for 3 unit reduction ( 2 6,000HP units replacing three 4,000HP units). Most road freights in North America need more than 6,000 HP. However unit reliability was a problem as a train would lose half it's available tractive effort with a failure...
challenger3980I think that another reason that you saw more Steam locomotives handling a train single handed is that the railroads had a lot wider variety of motive power to chose from in the steam era. Such as the Union Pacific, even many of their 1910's era 2-8-0's soldiered on right up to the end of steam in the late 50's Then they had 2-10-2's, 4-12-2's 2-8-8-2's 4-6-6-4 and 4-8-8-4's as well as others available. They matched the locomotive to the load and terrain to be crossed. If a 2-10-2 wasn't upt o the job, call out a Challenger, or Big Boy to handle the train. The later Challengers were designed and intended for a large part to work hand in hand with the Big Boys. The Challengers were built to handle a train that a Big Boy handled throught the Wasacht Mtns, take the same train through the lesser grades, and hand off that train off to a 2-10-2, or 4-12-2 in open country. A large part of this wide variety of power was due to the inability of Steam locomtives to MU, each Steam locomotive must have its own crew, so basically build a double Mountain (4-8-2) into a Big Boy, and you only need one crew to control the effective power of two locomotives. The diesel has the advantage of being able to consist together as many locomotives as needed, even DPU'd, and control all of them with one crew. Doug
Also a steam loco has unlimated hp. And a set torque. So a steamer would be able to handle a bigger load. I found out that the Challengers were made to take a train at high speed across the prarie, after the BB's too took them over the pass. Thanks for including this Doug!
If I may add a small quetion here... I have seen locomotives that throw fire from their stacks on URDVDS. Is the locomotive failing?
Also, You were talking about the AC6000CW in youre orignial post. UP of course scrapped their entire fleet of them. This locomotive looked better on paper than it actually was in real-world conditions. 6000 hp isn't enough for an intermodal train but 2 of them is way too mutch.
tpatrick When GE was designing the AC60, they intended to offer a single diesel unit powerful enough to pull a train single-handedly. They painted a picture of high speed strack trains zipping across the country led by a single AC60, but it didn't turn out that way. The railroads, instead, chose to pair a couple of 4400 hp units on the theory that if one fails you still have adequate power to get over the road, but slower. So that begs the question: Just how reliable are today's diesel units? Do they really fail so often that they are continuously in need of backup? Or are the consequences of a failure so dire that a railroad can't risk the occasional traffic jam? In steam days is was common to move a train with a single locomotive, with helpers where necessary. I can't believe a steamer was more reliable than a diesel, but maybe most steam failures didn't mean a complete loss of power while diesel failures are more likely catastrophic. So does anyone have statistics or personal experience that can shed some light on the question of just how reliable a diesel is?
When GE was designing the AC60, they intended to offer a single diesel unit powerful enough to pull a train single-handedly. They painted a picture of high speed strack trains zipping across the country led by a single AC60, but it didn't turn out that way. The railroads, instead, chose to pair a couple of 4400 hp units on the theory that if one fails you still have adequate power to get over the road, but slower. So that begs the question: Just how reliable are today's diesel units? Do they really fail so often that they are continuously in need of backup? Or are the consequences of a failure so dire that a railroad can't risk the occasional traffic jam?
In steam days is was common to move a train with a single locomotive, with helpers where necessary. I can't believe a steamer was more reliable than a diesel, but maybe most steam failures didn't mean a complete loss of power while diesel failures are more likely catastrophic.
So does anyone have statistics or personal experience that can shed some light on the question of just how reliable a diesel is?
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
tpatrickJust how reliable are today's diesel units? Do they really fail so often that they are continuously in need of backup? Or are the consequences of a failure so dire that a railroad can't risk the occasional traffic jam?
The severity of the conseqences of a failure depend on the trains involved. CSXT has sometimes added a third unit to two-unit consists in intermodal service to ensure that, if one of the other units fails, the train has enough horsepower to meet its schedule; and it has also sometimes added a third unit to coal drag consists to ensure that the trains will not stall if the other units do not meet their tonnage ratings.
One major difference in road failures between steam and diesel locos.
Unless the diesel has a traction motor failure that immobilizes the axle, the unit can usually be moved, even if not under its own power.
Steam failures tended to be semi- to fully catastrophic. Break a rod, and it will flail everything off that side of the locomotive [N&W J - generator 1/4 mile out in a farmer's field. MILW - engineer's side completely wiped out (lubricator failure.)] Let the water get low and you orbit a boiler...
Of the two, I'd rather by far be aboard a diesel when things go sour.
Chuck
Thanks everyone for responding to my question. Your answers were very informative and authoritative. I suspected the idea that second units are primarily backup was bogus and you confirmed that. I did not realize how widespread is the impact of a failure on the road. The dominoes fall every which way and in ways the outsider wouldn't imagine. It is interesting that the early dash-9s were so trouble prone, but often that it the case with new designs. It takes a while to work the bugs out. Thanks again for your observations and viewpoints. They shed some real light on the subject.
Amen to that.
Mechanical Department "No no that's fine shove that 20 pound set all around the yard... those shoes aren't hell and a half to change..."
The Missabe Road: Safety First
Today's yardmasters and locomotive managers take great delight in putting 14997 tons behind power that is rated for 15000 tons. Doesn't make any difference to them if that locomotive consist is one, two or more units. Maximum tonnage for the available power.
Never too old to have a happy childhood!
I 've heard it said that GE unit's are cheaper in price than EMD But not as high quality. Also thay don't last as long. An EMD unit however is more expensive but lasts longer. And is also more expensive to run. Each builder has it's own por's and con's. Just whatever the R.R. is willing to pay for. Also as stated before, you will have as many unit's as you need for youre load. Putting a loco on the train in anticapation of one failing would just be a waste of fuel as far as I'm concerned. Besides, correct me if I'm wrong here, it's probably not all the time that a unit fails. If it is a nucler flask train, that is a horese of a diffrent color though. Feel free to correct me if I'm wrong though anywhere in this post.
trainfan1221I do remember reading once, but remember this is an exception, that Penn Central used to throw a lot of units on some trains, expecting at least one to fail. This of course had to do with the condition of this railroad, but on some lines they couldn't take a chance of a train breaking down and blocking everything.
I do remember reading once, but remember this is an exception, that Penn Central used to throw a lot of units on some trains, expecting at least one to fail. This of course had to do with the condition of this railroad, but on some lines they couldn't take a chance of a train breaking down and blocking everything.
That's because their power was junk.
wabash1the idea that the railroads put 2 engines on 1 train as a back up if 1 fails is by far a joke. if you have 2 units that is because the first unit is withun 90% of tonage so they add a unit to help get you down the road, then they figure since you have all that power we will just add a few more cars ( no need in wasting power) to your train.
the idea that the railroads put 2 engines on 1 train as a back up if 1 fails is by far a joke. if you have 2 units that is because the first unit is withun 90% of tonage so they add a unit to help get you down the road, then they figure since you have all that power we will just add a few more cars ( no need in wasting power) to your train.
You nailed it.
the idea that the railroads put 2 engines on 1 train as a back up if 1 fails is by far a joke. if you have 2 units that is because the first unit is withun 90% of tonage so they add a unit to help get you down the road, then they figure since you have all that power we will just add a few more cars ( no need in wasting power) to your train. there is the rare instance that you are hauling extra power for a extra train. and if you have a 3700 ft 2200 ton train and 3 big units ( 4000 hp units) and think man i can get across the road fast with all on line, you will be the slowest train the most over worked engineer out there. first your gong to be speeding then you get dynamic and then your going slow then you get throttle now your speeding so we get dynamic and on and on and on. Back to the question when the dash 9s came out there was not a day that went by that you didnt have a dash 9 go down, always electrical and would not load, and the units to the rescue old sd40s and they would get the job done. now i will admit that the dash 9s are better than they use to be. I haft to agree with railway man that the reliability is at least 90% even on GE engines but i still prefer EMD.
tpatrickWhen GE was designing the AC60, they intended to offer a single diesel unit powerful enough to pull a train single-handedly. They painted a picture of high speed strack trains zipping across the country led by a single AC60, but it didn't turn out that way. The railroads, instead, chose to pair a couple of 4400 hp units on the theory that if one fails you still have adequate power to get over the road, but slower. So that begs the question: Just how reliable are today's diesel units? Do they really fail so often that they are continuously in need of backup? Or are the consequences of a failure so dire that a railroad can't risk the occasional traffic jam? In steam days is was common to move a train with a single locomotive, with helpers where necessary. I can't believe a steamer was more reliable than a diesel, but maybe most steam failures didn't mean a complete loss of power while diesel failures are more likely catastrophic. So does anyone have statistics or personal experience that can shed some light on the question of just how reliable a diesel is?
Current models are delivering in the high 90s availability rates. That measures the amount of time the locomotive is available for service vs. the amount of time it is not. Time not available includes refueling, FRA inspections, program maintenance, and unplanned maintenance. Thirty years ago we were seeing availability rates in the high 80s.
About 8 years ago, I kept track of how many locomotive failures I had over a six-month period during my shift on my territory that caused train delays. Average trains per shift per day was 35. Average days per week 5.5. Total trains measured, slightly more than 5000. After eliminating collisions with vehicles, rocks, trees, large animals, and washouts, locomotives running out of fuel, and crew mistakes such as forgetting to release handbrakes on a DPU, the answer is ... zero. However, we would never let a train out of a terminal with known poor performers, either.
The average train delay for a locomotive failure for any cause that I was then experiencing was in excess of 8 hours, it almost invariably required a recrew, and almost invariably delayed other trains up to 1-2 hours. Sometimes it affected only 1 or 2 other trains, sometimes it affected 20 or more. Train delays are extraordinarly costly because the event quickly ripples into the entire subdivision, the end terminals, and upsets crewcalling plans, yard blocking plans, service plans, car trip plans, and locomotive utilization plans, and usually affects train performance incentives and other service guarantees. It's difficult to measure the total cost because the effects linger for days and are subtle. But it is high.
The theory you cite above (that railways needed two units for protection) was never one I heard from the locomotive builders or at the railway, but instead what showed up in the media. I have no idea where the media got it from but my speculation is they invented it to justify why the railways were rejecting another theory I think they invented, that the 6,000 hp locomotive was the newest-bestest thing and would revolutionize railroading. We regularly ran empty coal, grain, and baretable trains with a single SD70MAC, AC4400CW, or SD60. Sometimes with a single SD40-2. We ran dozens of locals every day with single GP38-2s or GP40-2s. I can think of one time it didn't work and that's because the train was too heavy for the unit. I took one look at it on the turnover, said "that will never make it, and right there (pointing at the screen) is where it will fall down, so I will call the dog catch crew in 3 hours to meet them at X because they will have to double the hill and they will run out of time right there." And sure enough, that's exactly what happened.
The problem with the 6,000 hp units (beyond unanticipated low availability rates) is high cost, and lack of purpose and need. I always thought the sweet spot for a single 6,000 hp unit is a light train moving consistently at high speeds on a rather flat vertical profile with few speed restrictions and start/stop events. That train and route doesn't exist in current service plans on most Class 1s.
Steam locomotive failures were common and usually resulted in the train completely falling down. Again, the media exercises disservice because it prefers stories with heroic, happy endings rather than unhappy, mundane endings. For every story where the engine crew struggles in with the crack express to cheers and hail-good-fellows all around, there were a few hundred tonnage reductions, set-outs of complete trains into sidings, and spare engines called that didn't get celebrated in the press.
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