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Two electric questions

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Posted by Toddster on Monday, July 12, 2010 8:29 PM

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

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Posted by nanaimo73 on Monday, July 12, 2010 2:51 PM

GP40-2
1600 - 1700 HP max continuous duty, 2000+ HP short term rating per motor.

Thanks!

Dale
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Posted by GP40-2 on Monday, July 12, 2010 12:10 PM
nanaimo73

GP40-2
nanaimo73

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?

1600 - 1700 HP max continuous duty, 2000+ HP short term rating per motor.
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Posted by beaulieu on Monday, July 12, 2010 10:34 AM

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.

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Posted by CSSHEGEWISCH on Monday, July 12, 2010 10:22 AM

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.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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Posted by nanaimo73 on Monday, July 12, 2010 10:07 AM

GP40-2
nanaimo73

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?

Dale
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Posted by GP40-2 on Monday, July 12, 2010 8:23 AM
nanaimo73

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?
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Posted by nanaimo73 on Monday, July 12, 2010 12:15 AM

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.

Dale
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Posted by GP40-2 on Sunday, July 11, 2010 8:05 PM
Rainhilltrial

 GE's AC traction motor (generally known as the "GEB13" motor) is limited to 1000 horsepower.

Hmmm...Do you know that as an absolute fact, or are you just guessing based on the AC6000s 6000 nominal traction horsepower rating?
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Posted by Rainhilltrial on Sunday, July 11, 2010 5:53 PM

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.

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Posted by beaulieu on Sunday, July 11, 2010 10:08 AM

CSSHEGEWISCH

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.

 

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.

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Posted by CSSHEGEWISCH on Saturday, July 10, 2010 2:01 PM

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.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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Posted by beaulieu on Friday, July 9, 2010 12:53 PM

carnej1

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

 

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.

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Posted by carnej1 on Thursday, July 8, 2010 11:20 AM

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

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Two electric questions
Posted by nanaimo73 on Thursday, July 8, 2010 10:10 AM

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?

Dale

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