After looking at the GM10 locomotive, I'm thinking that 34 years later General Electric should be able to produce a 15,000 hp locomotive using an ES44AC platform. One question I have would be the pantograph, could a single pantograph handle the equivalent of 15,000 hp, or would it be necessary to use two pantographs? The other question regards transferring power to another locomotive. If the equivalent of 4500 hp was being fed the the traction motors of an adjoining ES44AC, could this be handled by a detachable cable, or would something more substantial (a power bus?) be required between the locomotives?
nanaimo73 After looking at the GM10 locomotive, I'm thinking that 34 years later General Electric should be able to produce a 15,000 hp locomotive using an ES44AC platform. One question I have would be the pantograph, could a single pantograph handle the equivalent of 15,000 hp, or would it be necessary to use two pantographs? The other question regards transferring power to another locomotive. If the equivalent of 4500 hp was being fed the the traction motors of an adjoining ES44AC, could this be handled by a detachable cable, or would something more substantial (a power bus?) be required between the locomotives?
And where is the market for such a beast? Seems to me that the European manufacturers have that end of the locomotive market well covered......I know the IORE locmotives built for a Swedish Iron ore line by Bombardier are actually joined two joined units with separate pantographs. IINM, these are the most powerful electric freight locomotives currently operating:
http://en.wikipedia.org/wiki/IORE
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
carnej1nanaimo73 After looking at the GM10 locomotive, I'm thinking that 34 years later General Electric should be able to produce a 15,000 hp locomotive using an ES44AC platform. One question I have would be the pantograph, could a single pantograph handle the equivalent of 15,000 hp, or would it be necessary to use two pantographs? The other question regards transferring power to another locomotive. If the equivalent of 4500 hp was being fed the the traction motors of an adjoining ES44AC, could this be handled by a detachable cable, or would something more substantial (a power bus?) be required between the locomotives? And where is the market for such a beast? Seems to me that the European manufacturers have that end of the locomotive market well covered......I know the IORE locmotives built for a Swedish Iron ore line by Bombardier are actually joined two joined units with separate pantographs. IINM, these are the most powerful electric freight locomotives currently operating: http://en.wikipedia.org/wiki/IORE
The Chinese have several series of Co-Co electrics rated at 9600Kw (12,860hp) that have more power than the Bombardier built IORE electrics. The Chinese locomotives were built with help from the European manufacturers.
Your could handle the power with a cable if the voltage is high enough.
The issue is not so much one of jumper cable vs. bus bar connecting two units as whether the electrical system (catenary, substations, etc.) could support the current draw. South Shore ran into this problem when it first began running unit trains in the mid-1960's.
CSSHEGEWISCHThe issue is not so much one of jumper cable vs. bus bar connecting two units as whether the electrical system (catenary, substations, etc.) could support the current draw. South Shore ran into this problem when it first began running unit trains in the mid-1960's.
That's a big problem with low voltage DC systems, it still plagues the Dutch railway system to this day. Voltage times the the Amperage equals the Power. Higher Voltage requires better insulation, higher Amperage requires a larger conductor wire, and/or bar, and more or larger contacts. Better quality insulation is an easier route than larger cabling. For the US I would recommend locomotives designed to run under both 25Kv and 50Kv. Use the highest voltage in rural areas to allow long distances between substations, use the 25Kv in metro areas where you have many overbridges and such to simplify the insulation and protection.
First, a couple of pieces of information about the ES44AC of today and yesterday's GM10B ..
GE's AC traction motor (generally known as the "GEB13" motor) is limited to 1000 horsepower. It was originally developed by GE back in 1993 with the 6000 horsepower 6-motor AC6000 locomotive in mind ... GE would use one common AC motor for the 4400 HP AC4400 and also for the 6000 HP AC6000.
Therefore, even though an "electric" ES44AC could theoretically draw much more than its rated (engine-produced) 4400 HP from overhead wires, the AC motors underneath are limited to only 6000 HP.
The GM10B used very-large DC motors which were frame-suspended ... actually hung up inside the locomotive underframe and protruding down into the truck frames.
Even if there was a freight railroad in the US with 25,000 or 50,000 volt AC overhead power ... I see little practical use for a 6-axle 15,000 HP electric locomotive. It would be essentially grossly overpowered. Why? Because you can't put that much horsepower down to the rails and consistently use it at the rails in contemporary US freight railroading. Can you put 15,000 HP down to 6-sets of wheels? Yes. But typially only for extremely high-speed low-tonnage applications. The Swiss, for example, have 10,000 HP 6-axle electric freight locomotives, and they are used on trains over the Alps and on Swiss-version unit trains (in Switzerland, a "unit train" typically consists of twenty-or-so covered hopper cars carrying cement ... roughly a 2000 ton train ... in the western US, railroads regularly move 135-to-145 car unit coal trains grossing over 20,000 tons. Why do European railroads have such high-power electric locomotives? One word answer: Speed. In Europe, railroads are (1) passenger movers and (2) freight movers particularly at night when most people aren't traveling.
The other practical limitation to your "15,000 HP Evolution locomotive" is adhesion ... the amount or percent of weight on powered wheels which can be converted into traveive effort or pulling force at the railhead. The best performance today is about 35% all-weather for US AC locomotives. All-weather means in dry weather, during rain, snow, sleet, mist, etc. An adhesion rating of 35% means that a 420,000 pound ES44AC can regularly develop about 147,000 pounds of tractive effort at about 8 MPH.
And that low-speed TE is essentially independent of horsepower. Horsepower doesn't become a factor until the locomotive has accelerated its train out past the "adhesion limited zone", out to about 15 MPH or more.
Bottom line ... if you could pack 15,000 HP into an ES44AC ... you wouldn't be able to effectively use that much power except for exceptionally high-speed low-tonnage service.
Would your mythical "ES150AC" perform like the equivalent of 3.4 ES44ACs? (4400 HP x 3.4 = 15,000 HP)
NO.
It would have practically no advantage in starting tonnage than an ES44AC, in fact it would have to be severely HP-limited to avoid dumping too much power to the rails and slipping down violently.
Yes, you could have two 6-motor locomotives drawing power from one pantograph, and that would be done using high-voltage connecting cables. But running with one pan per locomotive unit is safer and more practical.
As for the pantograph ... the pantograph on the roof of an electric locomotive (or electric self-propelled coach) does two things: It completes the circuit providing voltage from overhead contact wire (through the locomotive's control equipment and traction motors) down to the running rails (which are the "return conductor" for all that electricity), and it provides a path to the motors for the electrons which make up electrical current.
You could probably draw enough current to develop 15,000 HP on 6 powered axles, but the locomotive would have to be configured for minimal motor current (again, making it a "speed machine", not a "lugger"). There are limitations to the amount of amps which can be drawn not only thru the pantograph itself but also thru the overhead contact wire. (That's why electrified railroads have two types of dispatchers: train dispatchers who manage train movements for track condition etc and power dispatchers who manage the power drawn from the overhead wire by electric locomotives. In the world of electrified railways, if you allow too many electric locomotives in one small "zone" and they all try to accelerate their trains simultaneously ... you will overload the contact wire and probably the feeder wires and the substations.
Rainhilltrial GE's AC traction motor (generally known as the "GEB13" motor) is limited to 1000 horsepower.
GE's AC traction motor (generally known as the "GEB13" motor) is limited to 1000 horsepower.
Rainhilltrial, thanks for the information.
So GE could probably build a 15,000 electric freight locomotive, but only 6000 hp would be usable. Presumably it would be feasible to flank such a locomotive with modified ES44ACs, each drawing the equivalent of 4500 hp, thus using the 15,000 hp? I'll guess this would cost less than buying 3 5000 hp electrics for a mainline electrification, but there would be a loss in flexiblity.
nanaimo73 So GE could probably build a 15,000 electric freight locomotive, but only 6000 hp would be usable.
So GE could probably build a 15,000 electric freight locomotive, but only 6000 hp would be usable.
GP40-2nanaimo73 So GE could probably build a 15,000 electric freight locomotive, but only 6000 hp would be usable. What is your definition of "usable", and what makes you think 6000 HP would be the limit?
I really don't know, I'm just a nutty railfan. My definition of usable would be for freight service at speeds up to 70 mph on a mainline (say BNSF San Bernardino to Galesburg). Obviously the traction motors on an ES44C4 can handle at least 1100 hp each. Can you share any of your knowledge on those motors? Could three of them use 4400 hp if one traction motor was not operable?
As mentioned earlier, adhesion is the great limiting factor to putting 15000 HP (continuous?) on one C-C frame. Consider the VGN EL-2b of 1948: rated at 6800 continuous horsepower, two units with eight traction motors each, at a time when a 1500 HP B-B was a standard road diesel locomotive. Amtrak's AEM7's were rated at 7000 HP on 4 axles, but they were built for speed, not tonnage.
RainhilltrialEven if there was a freight railroad in the US with 25,000 or 50,000 volt AC overhead power ...
Even if there was a freight railroad in the US with 25,000 or 50,000 volt AC overhead power ...
May I take this to mean you are unaware of the Black Mesa & Lake Powell RR, and the Deseret & Western RR, both of which are freight only and are electrified at 50Kv?
I do agree with you that a 15,000hp electric is highly unlikely for US railroads if they electrified, but I could readily see them bump the current 4400hp up to say the 6000hp range. This would be useful on Intermodal trains, particularly with DPU.
nanaimo73GP40-2nanaimo73 So GE could probably build a 15,000 electric freight locomotive, but only 6000 hp would be usable. What is your definition of "usable", and what makes you think 6000 HP would be the limit? I really don't know, I'm just a nutty railfan. My definition of usable would be for freight service at speeds up to 70 mph on a mainline (say BNSF San Bernardino to Galesburg). Obviously the traction motors on an ES44C4 can handle at least 1100 hp each. Can you share any of your knowledge on those motors? Could three of them use 4400 hp if one traction motor was not operable?
GP40-21600 - 1700 HP max continuous duty, 2000+ HP short term rating per motor.
Thanks!
Yes, the Harmony HXD3B units by Bombardier/Dalian are a whopping 12,860 Hp. Wow! It is mind boggling to think how they accomplished that. GE talks about developing an electric, but as you can see, between the Harmony, Bombardier IORE, and others, the competition is fierce. Not to mention Bombardier has a fleet of Traxx series all over the European continent, and a gigantic factory in Germany.
http://en.wikipedia.org/wiki/List_of_locomotives_in_China
beaulieu Rainhilltrial Even if there was a freight railroad in the US with 25,000 or 50,000 volt AC overhead power ... May I take this to mean you are unaware of the Black Mesa & Lake Powell RR, and the Deseret & Western RR, both of which are freight only and are electrified at 50Kv? I do agree with you that a 15,000hp electric is highly unlikely for US railroads if they electrified, but I could readily see them bump the current 4400hp up to say the 6000hp range. This would be useful on Intermodal trains, particularly with DPU.
Rainhilltrial Even if there was a freight railroad in the US with 25,000 or 50,000 volt AC overhead power ...
As it appears that north american railroads using 6000hp diesel units are dropping them (UP, CSX, CP with GE AC6000 or SD90MACS, I mean SD90 and not SD9043), I hardly imagine that electric units of the same power could be used one of these days in the US, had the electrified freight railroads (BM&LP, Deseret & Western) the need to renew their fleet.
Dom
ddechamp71 beaulieu Rainhilltrial Even if there was a freight railroad in the US with 25,000 or 50,000 volt AC overhead power ... May I take this to mean you are unaware of the Black Mesa & Lake Powell RR, and the Deseret & Western RR, both of which are freight only and are electrified at 50Kv? I do agree with you that a 15,000hp electric is highly unlikely for US railroads if they electrified, but I could readily see them bump the current 4400hp up to say the 6000hp range. This would be useful on Intermodal trains, particularly with DPU. As it appears that north american railroads using 6000hp diesel units are dropping them (UP, CSX, CP with GE AC6000 or SD90MACS, I mean SD90 and not SD9043), I hardly imagine that electric units of the same power could be used one of these days in the US, had the electrified freight railroads (BM&LP, Deseret & Western) the need to renew their fleet. Dom
The coal haulers you mention currently operate 6,000 HP GE E60C locomotives (with DC traction motors). The heavy haul electric freight locomotive offerings on the market currently (From Bombardier and Alstom) are considerably more powerful than that, were they in the market for replacement power, I would imagine it would be something like the Bombardier IORE locomotives operating in Sweden, which are 7,200 HP six axle units with AC traction motors..
ddechamp71As it appears that north american railroads using 6000hp diesel units are dropping them (UP, CSX, CP with GE AC6000 or SD90MACS, I mean SD90 and not SD9043), I hardly imagine that electric units of the same power could be used one of these days in the US
(By the way, the E60C on BM&LP etc is 5100 continuous rail hp.)
timz [snip] An AC44 with full tonnage is making maybe 8 mph; 10-11 mph from an AC60 would be a help. A US main line freight RR that electrified today would want 9000+ rail hp per unit. [snip]
Interesting discussion. timz's "9,000 rail HP per unit" [emphasis added for at the rail] - that's around 10,000 HP / 7,460 kw = 7.5 MW power input. Taking a "unit" to be a C-C with the usual 'loading gauge' limits of around 70,000 lb. axle loading/ 420,000 lb. gross weight, at 35 % adhesion = 147,000 lbs. Tractive Effort likewise at the rail, implies a typical speed of about 23 MPH or better in order to fully utilize that HP.
That's a little higher than is currently typical for some mountain grades - such as the East Slope/ Horse Shoe Curve, where around 16 MPH seems to be the norm - but those are about the only places all that TE and HP could be put to use for a sustained time, so it might lead to slight speed-ups there. Otherwise, the low 20's is a typical average train speed for most unit and general freight trains (non-intermodal). Perhaps there too the power and TE available from such a unit and needed by the train could be closely matched to the service so as to maximize the usage of all of the unit's capabilities; or else they could be used in intermodal service where the average speed is in the upper 30 MPH range, which therefore needs much more HP.
- Paul North.
Paul_D_North_Jrtimz [snip] An AC44 with full tonnage is making maybe 8 mph; 10-11 mph from an AC60 would be a help. A US main line freight RR that electrified today would want 9000+ rail hp per unit. [snip] Interesting discussion. timz's "9,000 rail HP per unit" [emphasis added for at the rail] - that's around 10,000 HP / 7,460 kw = 7.5 MW power input. Taking a "unit" to be a C-C with the usual 'loading gauge' limits of around 70,000 lb. axle loading/ 420,000 lb. gross weight, at 35 % adhesion = 147,000 lbs. Tractive Effort likewise at the rail, implies a typical speed of about 23 MPH or better in order to fully utilize that HP. That's a little higher than is currently typical for some mountain grades - such as the East Slope/ Horse Shoe Curve, where around 16 MPH seems to be the norm - but those are about the only places all that TE and HP could be put to use for a sustained time, so it might lead to slight speed-ups there. Otherwise, the low 20's is a typical average train speed for most unit and general freight trains (non-intermodal). Perhaps there too the power and TE available from such a unit and needed by the train could be closely matched to the service so as to maximize the usage of all of the unit's capabilities; or else they could be used in intermodal service where the average speed is in the upper 30 MPH range, which therefore needs much more HP. - Paul North.
Yes, but your thinking Eastern, while I am thinking Western. Specifically the BNSF eastbound from the Colorado River bridge to the top of the Arizona Divide going from 456ft. above sea level to 7,322 ft. above sea level in about 220 miles, very few speed restrictions lower than 40 mph, 70 mph top speed for Intermodals. I can't find my copy of the relevant Trains Magazine to be more exact. Not a helper grade since steam days, but a long slog at full throttle.
beaulieuPaul_D_North_Jrtimz [snip] An AC44 with full tonnage is making maybe 8 mph; 10-11 mph from an AC60 would be a help. A US main line freight RR that electrified today would want 9000+ rail hp per unit. [snip] Interesting discussion. timz's "9,000 rail HP per unit" [emphasis added for at the rail] - that's around 10,000 HP / 7,460 kw = 7.5 MW power input. Taking a "unit" to be a C-C with the usual 'loading gauge' limits of around 70,000 lb. axle loading/ 420,000 lb. gross weight, at 35 % adhesion = 147,000 lbs. Tractive Effort likewise at the rail, implies a typical speed of about 23 MPH or better in order to fully utilize that HP. That's a little higher than is currently typical for some mountain grades - such as the East Slope/ Horse Shoe Curve, where around 16 MPH seems to be the norm - but those are about the only places all that TE and HP could be put to use for a sustained time, so it might lead to slight speed-ups there. Otherwise, the low 20's is a typical average train speed for most unit and general freight trains (non-intermodal). Perhaps there too the power and TE available from such a unit and needed by the train could be closely matched to the service so as to maximize the usage of all of the unit's capabilities; or else they could be used in intermodal service where the average speed is in the upper 30 MPH range, which therefore needs much more HP. - Paul North. Yes, but your thinking Eastern, while I am thinking Western. Specifically the BNSF eastbound from the Colorado River bridge to the top of the Arizona Divide going from 456ft. above sea level to 7,322 ft. above sea level in about 220 miles, very few speed restrictions lower than 40 mph, 70 mph top speed for Intermodals. I can't find my copy of the relevant Trains Magazine to be more exact. Not a helper grade since steam days, but a long slog at full throttle.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
beaulieu Yes, but your thinking Eastern, while I am thinking Western. Specifically the BNSF eastbound from the Colorado River bridge to the top of the Arizona Divide going from 456ft. above sea level to 7,322 ft. above sea level in about 220 miles, very few speed restrictions lower than 40 mph, 70 mph top speed for Intermodals. I can't find my copy of the relevant Trains Magazine to be more exact. Not a helper grade since steam days, but a long slog at full throttle.
Right you are. Thanks for that example, too - for intellectual honesty, I've also been trying to think of a long, really long and heavy grade situation, where an electric locomotive can't really rely upon or use its short-time motor overload capability to out-perform an equivalent diesel. On that one, it's several hours to make that climb, so they're both going to be limited to their continuous ratings.
I believe that Trains article might be the one by Richard Steinheimer in the 1970's - 1980's time frame - perhaps titled "Arizona Divide" or similar. However, I was just shocked to see that Kalmbach has removed the "Index to Magazines" tool/ application due to obsolescence and security concerns, which is understandable, so I no longer have my easy and fun way to look up that kind of thing.
timz ddechamp71As it appears that north american railroads using 6000hp diesel units are dropping them (UP, CSX, CP with GE AC6000 or SD90MACS, I mean SD90 and not SD9043), I hardly imagine that electric units of the same power could be used one of these days in the USI'm guessing US RRs would love a 6000 hp diesel if it were reliable. An AC44 with full tonnage is making maybe 8 mph; 10-11 mph from an AC60 would be a help. A US main line freight RR that electrified today would want 9000+ rail hp per unit. (By the way, the E60C on BM&LP etc is 5100 continuous rail hp.)
I've read here and there that the primary concern with 6000 hp diesel units for railroads using them was unspread power. I mean, when a railroad needs to move a freight train it needs what we could call a "block of power", ie total horsepowers and tractive effort. Translating this into models, we could say that 3 AC4400s roughly equal 2 AC6000s. As far as I remember, the concern was: if one unit fails, the bi-unit consist loses 50% of its power, as the 3-unit consist loses 1/3 of its power, and so on.
But maybe I'm not aware of the latest issues dealing with these powerful 6000 hp diesels. What about BHP Billiton in Australia, the only other railroad that operates them?
Paul_D_North_JrRight you are. Thanks for that example, too - for intellectual honesty, I've also been trying to think of a long, really long and heavy grade situation, where an electric locomotive can't really rely upon or use its short-time motor overload capability to out-perform an equivalent diesel. On that one, it's several hours to make that climb, so they're both going to be limited to their continuous ratings.
Time/motion studies have consistently shown that a key advantage of electric locomotion isn't particularly in having the overload capacity available for grades. Older electric types did have a pretty hefty overload rating; these days, using identical off-the-shelf traction motors, the advantage over a comparable diesel-electric isn't that great. It's there, maybe about 10% (1 hr rating), and that could offer a couple mph advantage, if that's of any particular significance.
The real operating advantage however is in using the higher short-term (10-20 min) overload capacity in and out of sidings. The time/motion studies show that Electrification offers a significant advantage, but this is at the very low speeds involved, and so it may be fairly said that a key advantage gets back to the TE available, and not the HP. As a "for instance," reducing siding time by a mere two minutes, by being able to accelerate out quicker, can increase line capacity on a division by two trains per day. It makes that much difference.
In that context, the operating advantage of Electrification translates into a significant revenue productivity.
Of course, in the long, heavy grade scenario, Electrification's big advantage in any case is not in going uphill.
Electrification really shines going downhill by recapturing up to 50% of energy used going uphill.
ICLandElectrification really shines going downhill by recapturing up to 50% of energy used going uphill
creepycrankICLandElectrification really shines going downhill by recapturing up to 50% of energy used going uphill How do they do that? If the catenary is AC then the returned power would have to be the same voltage, the same frequency, and in phase.
With something called an inverter...
Inverters for tying solar cell arrays to the electric grid have been available for more than a decade, though electric locomotive service has at leas a few -um- features not typically found in solar power installations.
Also bear in mind that the phase converter locomotives used by the N&W and the VGN along with the MG locomotives used by the GN and VGN were capable of regenerative braking.
You are correct that the short-time overload capacity of electrics vs diesels is much greater with older diesels, and specifically electrics vs. dc motor diesels. AC motor diesels have much the same advantage as AC motor electrics.
Interesting topic.Horsepower and locomotives are often a confusing subject.Electric locomotives may have a lot of horsepower but you are always going to be limited by how much you can pull by how much your locomotive weighs.It wouldn't matter if you had a 30,000 hp locomotive.If your locomotive is going to slip the wheels trying to pull a heavy train it is useless no matter how much horsepower you have.
Electric locomotives are mainly used for high speed rail passenger service.They may have very high horsepower but that does not mean they are any stronger than your average freight locomotive.I doubt a Acela could pull 40 cars up a grade.They were designed and geared for high speed.It's the same with top fuel dragsters.They average 9,000 horsepower but they couldn't pull a loaded semi trailer up a steep grade.
I can't remember the locomotive name but it was made by GE in the 1970's and had a B-B-B wheel arrangement,was electric,painted white,and was rated at 10,000 hp.It was a sucessful locomotive but the railroads said they were not interested because it was too risky putting a single locomotive on a freight train in case it broke down somewhere.If you did have to have a second locomotive as a back up it might as well be running so you really only needed two 5000 hp locomotives.As a former locomotive mechanic I can tell you that the more horsepower these locomotives have the more problems you will get.Some of those higher horsepower locomotives also tend to load up much faster then your older ones.I can remember having a 6000 hp locomotive in the front of a train with 4 more locomotives behind it and it would load up so fast it was trying to pull the entire train right away while the 4 locomotives behind it was just starting to load up.
The Milwaukee road was probably the best managed electric freight railroad of all time.They had the right ideas.Heavy locomotives with lots of wheels.
daveklepperYou are correct that the short-time overload capacity of electrics vs diesels is much greater with older diesels, and specifically electrics vs. dc motor diesels. AC motor diesels have much the same advantage as AC motor electrics.
Interestingly, the modern AC traction motor diesel-electric will likely reduce the costs of Electrification if and when railroads ever get around to it, ironically by lowering the costs of the motive power and permitting the use of high voltage DC overhead instead of AC, since the inverters to take advantage of a DC supply system are already built into the off-the-shelf AC diesel-electric. The use of high voltage DC will significantly reduce the physical cost of the building the overhead.
Thomas 9011 Interesting topic.Horsepower and locomotives are often a confusing subject.Electric locomotives may have a lot of horsepower but you are always going to be limited by how much you can pull by how much your locomotive weighs.It wouldn't matter if you had a 30,000 hp locomotive.If your locomotive is going to slip the wheels trying to pull a heavy train it is useless no matter how much horsepower you have. Electric locomotives are mainly used for high speed rail passenger service.They may have very high horsepower but that does not mean they are any stronger than your average freight locomotive.I doubt a Acela could pull 40 cars up a grade.They were designed and geared for high speed.It's the same with top fuel dragsters.They average 9,000 horsepower but they couldn't pull a loaded semi trailer up a steep grade. I can't remember the locomotive name but it was made by GE in the 1970's and had a B-B-B wheel arrangement,was electric,painted white,and was rated at 10,000 hp.It was a sucessful locomotive but the railroads said they were not interested because it was too risky putting a single locomotive on a freight train in case it broke down somewhere.If you did have to have a second locomotive as a back up it might as well be running so you really only needed two 5000 hp locomotives.As a former locomotive mechanic I can tell you that the more horsepower these locomotives have the more problems you will get.Some of those higher horsepower locomotives also tend to load up much faster then your older ones.I can remember having a 6000 hp locomotive in the front of a train with 4 more locomotives behind it and it would load up so fast it was trying to pull the entire train right away while the 4 locomotives behind it was just starting to load up. The Milwaukee road was probably the best managed electric freight railroad of all time.They had the right ideas.Heavy locomotives with lots of wheels.
You are referring to the EMD ASEA GM10 which is what started this topic of in the first place...it was a b-b-b locomotive adapted from a succesful Swiss Railways locomotive design. It didn't go into production because the only US mainline electric freight operator, Conrail, wasn't in the market for new electrics at that time, and the other US railroads studying electrification in the 1970's did not go forward with putting up catenary.
Electrics are historically more reliable than diesels and in parts of the world where electrification is the norm it is common to see single units on even heavy freights. PRR and New Haven commonly ran freight trains with single electric locos back during the "golden age" of under wire operations..
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