I don't visit this forum much, so maybe my Q has been answered. Anyway, here it is: What's the latest on both EMD & GE 'convertibles'? Has either come out with a full 6000 Hp version?
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phil gresho posted:I don't visit this forum much, so maybe my Q has been answered. Anyway, here it is: What's the latest on both EMD & GE 'convertibles'? Has either come out with a full 6000 Hp version?
They both did, quite some years ago. Neither were all that successful and the railroads finally realized that a single 6000HP unit was what they needed nor wanted. Think they are long gone by now.
This was a case where more was definitely not better. 6,000 HP on 6-axle unit (1,000 HP per axle) was just too much. It pushed the limits of wheel slip right to the edge...and beyond. And, as Wyhog stated, you could not use all that HP on a heavy drag freight anyway.
The industry seems to have figured out that 4,400 hp is about all that you can expect to reliably use in a 6-axle unit.
What is being said about 4400 hp being the limitation is just for United States/Canada, not for the rest of the world.
Brazil uses the ES58ACi (ok 5800 hp, not 6000) in heavy freight service. In China there is the HNX5 locomotive which is 6250 hp. Both of these units use the GEVO V16 prime mover. The CSX AC6000CW's have been equipped with the same GEVO V16, upgraded computer systems and rated at 6000 hp which essentially now makes them ES60AC's.
In India there is the WDG5 which is EMD/710 product rated at 5500 hp and is used in both heavy freight and passenger service.
I could go on, but the rest of the world obviously does not feel the same way.
Lighter tonnage would have a lot to do with that .
It's been continually proven for over a 100 years. What works in other parts of the world often doesn't work here. You don't really need (or want) 1,000 HP per axle to move 10-15,000 ton drags and mile and a half long stack trains. Look at the trains the US Steel Roads moved for decades with 1750-2000 HP 6 axle SD's.
I think than when CSX bought into the 6000 hp locomotives, the CW6000AC's, they were never meant to
be used in drag service. One never saw them here on 17mile, and CSX got busy improving the
CW44AC's for drag service back here. Testing on grades like 17 mile resulted in the "heavy" 44's. weight
ballasted and improved wheel slip systems, and steerable trucks. While that was going on, all the 6000's
were west of here,in high speed freight service.
The first few years of this, before the power units began to fail, I would
see them at the shops, the top parts of them stained with exhaust, you could tell they ran miles at speed.
They finally had to derate horsepower of them, when the engines went bad. You can to this day see them
anywhere on the system, even on coal drags. Having said all that, it seems to me that having those
locomotives used just on high speed service is not as useful as having locomotives that can be used
in any service. 4400hp six axles seem to be the perfect balance, for almost every kind of service.
Ed
Dieselbob posted:It's been continually proven for over a 100 years. What works in other parts of the world often doesn't work here. You don't really need (or want) 1,000 HP per axle to move 10-15,000 ton drags and mile and a half long stack trains. Look at the trains the US Steel Roads moved for decades with 1750-2000 HP 6 axle SD's.
Or a case of the reverse. SP used the SD45's on tough grades with speeds so low, the traction motor meters were in the "red zone". They were burning out traction motors. However, the SD9's could do the same job like Timex watches or Pink Bunnies. Sometimes "more power" is NOT what you need.
Good points made in the last two posts. In my opinion, "special service" locomotives like 6000 HP units and BNSF's C4's are a bad idea, because eventually, ANY locomotive will get assigned to ANY job, ones they may not be well suited for. I would take a fleet of 4000-4400 six axle AC machines that can tackle most any job all day long. Back to the SD9 comment, does ANYTHING beat the sound of a couple of SD7, 9, 18 or 38's hammering upgrade on a hard pull?
To answer your last question.......NO ! Ain't gonna happen. EMD; sound the best , run the best. Thank you, Mr. Dilworth.
jaygee posted:Lighter tonnage would have a lot to do with that .
The ore trains in Brazil are the most massive ore trains in the world in regular operation. Estrada de Ferro Carajás uses three of the ES58ACi's in place of four 4400 hp units. These trains consist of 336 loaded ore cars.
This, like all other motive power, is application related, and the builders are not "stupid" in this regard. The 6000 HP units were all designed to replace two SD40's, a unit reduction scenario that also resulted in improved fuel economy and emissions. With the cost to develop brand new diesel engines, this was not a "snap decision" by either builder. I looked at a lot of these applications, and one remains in my memory. Two AC4400's on a tonnage train on the most severe gradient and max tonnage would achieve a balance speed of 10 mph. Two AC6000's with the same exact train would balance out at 12 mph. Not much productivity there.....and wasted HP and fuel to boot.
BUT
Where two AC4400's would balance on level track with max tonnage at 50 mph, the two AC6000's with max tonnage would achieve a balance speed of 67 mph. The "home" of 6000 HP units was (and is) in van and intermodal service. At the time that the 6000 HP units were being designed, mineral was growing only in selected markets (Powder River Basin) while intermodal was growing almost everywhere. The railroads wanted to buy motive power where they could achieve the best bang for the buck.
You might know that AC4400's were sized so that two AC4400's could displace three GP40's. The slight reduction in total HP vs 3 GP's was offset by higher transmission efficiency so rail HP and run times were the same. And those AC4400's saved a LOT of fuel, by some accounts up to 17% per trip. CSX had, I believe, almost 400 GP40's. Now they don't have any.....
The two hard and fast rules in this game are:
The builders will build whatever the railroads want to buy, and
The railroads will buy whatever makes the best economic sense.
WBC posted:What is being said about 4400 hp being the limitation is just for United States/Canada, not for the rest of the world.
Brazil uses the ES58ACi (ok 5800 hp, not 6000) in heavy freight service. In China there is the HNX5 locomotive which is 6250 hp. Both of these units use the GEVO V16 prime mover. The CSX AC6000CW's have been equipped with the same GEVO V16, upgraded computer systems and rated at 6000 hp which essentially now makes them ES60AC's.
In India there is the WDG5 which is EMD/710 product rated at 5500 hp and is used in both heavy freight and passenger service.
I could go on, but the rest of the world obviously does not feel the same way.
From what I understand the CSX C60AC units have been, or are being repowered, with GEVO 16 prime movers rated at 4600HP. They are classified by CSX as ES46AC units.
PAUL ROMANO posted:From what I understand the CSX C60AC units have been, or are being repowered, with GEVO 16 prime movers rated at 4600HP. They are classified by CSX as ES46AC units.
Were they recently de-rated to 4600 hp?
There are many threads when the work was done that the 6000 hp rating was retained when the GEVO primer mover was installed.
http://www.railroadforums.com/...-628-re-engined-GEVO
http://www.trainorders.com/dis...n/read.php?2,1570043
http://www.trainorders.com/dis...n/read.php?2,3158145
SCL and AT at one time had the U36B, 900 HP per axle. AT's were used on SCL, and on a passenger train. But SCL? Did they run that many high speed FREIGHT trains? Did not GE then build slugs for the U-boats?
Dieselbob posted:Good points made in the last two posts. In my opinion, "special service" locomotives like 6000 HP units and BNSF's C4's are a bad idea, because eventually, ANY locomotive will get assigned to ANY job, ones they may not be well suited for. I would take a fleet of 4000-4400 six axle AC machines that can tackle most any job all day long. Back to the SD9 comment, does ANYTHING beat the sound of a couple of SD7, 9, 18 or 38's hammering upgrade on a hard pull?
F7's or 9's?
On SCL, changing requirements dictated the need for MATES (Motors for Additional Tractive Effort). SCL had a surplus of U36's, and at 900 hp/axle they were not optimum for service in the "bone valley" of FL. So GE responded to the SCL dilemma by offering "slugs" with motors but no engine and no main generator/(alternator). Now the RR could assemble a mother and a slug with 450 HP per traction motor. This MCS (Minimum Continuous Speed) of that combination was now about 9 mph, ideal for a mineral application.
So is the horse power rating that of the prime mover or the traction motors?
Form D posted:So is the horse power rating that of the prime mover or the traction motors?
Diesel units are rated "at the rail", thus the prime mover must produce some 200 addition HP in order to supply the auxiliaries.
Here's an interesting and detailed discussion about tractive effort, Horsepower and the physics of moving a train. As someone pointed out earlier in this post, adhesion is a key issue, along with the limitations imposed by how much weight can be carried by each wheel - discussed below:
http://www.alkrug.vcn.com/rrfacts/hp_te.htm
This site is from early in this century (the physics shouldn't be time-dependent) and there is not much discussion about emissions...
After seeing the Topic " 6000 Hp diseasels" and then reading the thread, I am disappointed.
I thought this was something Frank Zappa related to trains.
Moonman posted:After seeing the Topic " 6000 Hp diseasels" and then reading the thread, I am disappointed.
I thought this was something Frank Zappa related to trains.
Apparently the original poster didn't know how to spell "Diesel"?
That detailed and easily understood discussion of Tractive Effort and Horsepower was written by OGR Forum member Al Krug. His forum screen name is "Wyhog."
Hot Water posted:Moonman posted:After seeing the Topic " 6000 Hp diseasels" and then reading the thread, I am disappointed.
I thought this was something Frank Zappa related to trains.
Apparently the original poster didn't know how to spell "Diesel"?
"Diseasels" (the disease that wipe out steam) is the allegedly funny term used by folks that don't really care about or have no respect for diesel locomotives.
Rusty
Rusty Traque posted:Hot Water posted:Moonman posted:After seeing the Topic " 6000 Hp diseasels" and then reading the thread, I am disappointed.
I thought this was something Frank Zappa related to trains.
Apparently the original poster didn't know how to spell "Diesel"?
"Diseasels" (the disease that wipe out steam) is the allegedly funny term used by folks that don't really care about or have no respect for diesel locomotives.
Rusty
Oh. That explains it then. I remember having cases of "GE measles" and "EMD measles" when walking to close to a unit with a bad piston or bad rings, etc., and that stuff usually does NOT wash out of your shirt.
Yes, indeed ! This WAS my intent; at least in part. [The humorous part.] I respect diesels, but I LOVE steamers!
I do love steam more, I guess. But to stand near the top of Sand Patch, and hear
8800 GE horsepower lugging tons of coal up the hill is special, even more when
it's two Mac 70's those EMD's have a sound all their own wound clear up!
Ed
Ed Mullan posted:I do love steam more, I guess. But to stand near the top of Sand Patch, and hear
8800 GE horsepower lugging tons of coal up the hill is special, even more when
it's two Mac 70's those EMD's have a sound all their own wound clear up!
Ed
Good point, Ed. Then again, you should hear what the UP DDA40X units sounded like at full load. The DDA40X units had the highest horsepower prime movers that EMD ever produced, WITHOUT EXHAUST SILENCERS!
Hot Water posted:Ed Mullan posted:I do love steam more, I guess. But to stand near the top of Sand Patch, and hear
8800 GE horsepower lugging tons of coal up the hill is special, even more when
it's two Mac 70's those EMD's have a sound all their own wound clear up!
Ed
Good point, Ed. Then again, you should hear what the UP DDA40X units sounded like at full load. The DDA40X units had the highest horsepower prime movers that EMD ever produced, WITHOUT EXHAUST SILENCERS!
UP 6936 was at the Houston Amtrak station on a business special. Indeed it is LOUD! But I did see sparks coming out of the 2 exhausts. No spark controls items here either?
I love the sound of EMD engines notch 8................
The "horsepower race" of the late 1990s did provide some excitement for enthusiasts at a time when the eastern US was in the doldrums of the Conrail takeover and there was little mainline steam.
SD80 and SD90 MACS plus the GE CW60s did give an impressive appearance, even though the concept was flawed.
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I thought the SD80's were successful for the railroad that ordered them: Conrail. Then, from what I understand, CR did a study, and the max HP the road needed was 5000.
Dominic Mazoch posted:I thought the SD80's were successful for the railroad that ordered them: Conrail. Then, from what I understand, CR did a study, and the max HP the road needed was 5000.
Correct, and THAT is exactly why Conrail ordered the 5000 HP SD80MAC units instead of the SD90MAC 6000 HP units. What was even funnier at the time, the "other railroads" laughed up their sleves at Conrail for making such a "mistake". Well, even though Conrail is long gone, who had the "last laugh"?
A slight correction...
Diesel HP is not measured at the rail. Diesel HP is quoted as "Net Input HP into the traction alternator under standard conditions, which is usually at 60 degr and altitude of 1000 ft". The net input HP has already had subtracted the parasitic load (ie cooling fans, etc.)
There are correction factors used for differences in temperature and altitude.
Now comes the fun....
Since you cannot EASILY measure diesel engine torque directly, the builders determine the efficiency of the alternator at each speed that it runs (rpm), and measure volts and amps output into the rectifiers at those speeds. Then you can work backwards and use the volts x amps/.746 and the alternator efficiency to determine how much HP the diesel engine is putting into the alternator.
If you can measure drawbar pull in pounds and exact speed, you can easily determine drawbar HP (at the coupler). This is where dynamometer cars are useful. A strong case is always made by the railroads that "everything on the locomotive side of the coupler is irrelevant, and only drawbar pull is important in hauling the train." Then you tell them about fuel consumption, which is THE elephant in the room, and which drives ALL of the economics.....
Hot Water posted:Dominic Mazoch posted:I thought the SD80's were successful for the railroad that ordered them: Conrail. Then, from what I understand, CR did a study, and the max HP the road needed was 5000.
Correct, and THAT is exactly why Conrail ordered the 5000 HP SD80MAC units instead of the SD90MAC 6000 HP units. What was even funnier at the time, the "other railroads" laughed up their sleves at Conrail for making such a "mistake". Well, even though Conrail is long gone, who had the "last laugh"?
Indeed! All but one of those SD80MAC's (CSX wrecked and scrapped it) are still working in mainline service on NS, while many of the 6000 HP SD90MAC's and GE AC6000's are either downrated, re-engined or just gone.
Please do not misunderstand me, I'm quite fond of EMD locomotives as they built the finest diesel electric locomotives I operated (approximately 1Mil miles in Class 1 mainline service over my career) but…..based on my experience with the Conrail SD80MAC's, they were the lousiest locomotives produced by EMD since the GP/SD 35's. The SD80's were poor performers, prone to wheel slip at various speeds. The GP 35's had transition problems that kept them from reaching their 2500HP potential (at least when I ran them in the late 70's and early 80's). That being said, I'd still choose a GP 35 over ANY U series GE/ALCO.
As for the extreme high horsepower (5000HP and above) topic, as an engineer, I would much rather have two GP40's (6000 HP) or even three veteran GP9's (5250HP) over a single super unit for many reasons. I understand the economics of one locomotive vs. two or three, but for pure performance give me more axles and prime movers any day.
Just my observations on the subject.
Chris
Hudson5432 posted:Diesel HP is not measured at the rail. Diesel HP is quoted as "Net Input HP into the traction alternator under standard conditions, which is usually at 60 degr and altitude of 1000 ft". The net input HP has already had subtracted the parasitic load (ie cooling fans, etc.)
Using the traction curve for an ES44AC taken from here:
http://citeseerx.ist.psu.edu/v...ep=rep1&type=pdf
one can calculate the horsepower at any given speed. The above graph makes it very easy as the force is in Newtons and the velocity is in meters per time (metric, or SI units). That gives the units Nm/s (Newton meters/seconds) which is the unit for the watt. The watt is the standard for power (745.7 watts per hp). 800 kN is just about 180,000 pounds and 120 kph is 75 mph.
An ES44AC produces pretty much a steady 4000 hp at the rail from 10 mph to 75 mph as calculated from the traction curve.
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These last charts are way cool - helps explain a lot of this. But it also leads to a dumb question on my part, since it isn't immediately obvious to me why adhesion is such a sharp function of velocity - a factor of 8 drop between 10 and 75 mph. Or does the answer lurk in the definition of adhesion (and not the physics??)?
BTW, good demonstration of the use of metric (SI) units. We'd have been there 15 years ago if it were not for good ol' RR
WBC posted:Using the traction curve for an ES44AC taken from here:
Thank you, WBC. I appreciate the information.
But, are other folks having a problem reading this file?
