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ES44C4 Mechanics

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ES44C4 Mechanics
Posted by aut1rml on Thursday, October 01, 2009 9:10 AM

I am looking for information on the workings of the traction control of the ES44C4. The mechics of the system rather than electronic. From the looks of the picturers that I have seen it looks very basic, somehow the air cylinders via linkage piviot a device to unload the axle. How does this work? It also seems to me that just shuting off power to a traction motor on a given axle to save fuel would cause quite a bit of drag.  Reverse gear reduction turning a large unpowered motor. It makes me wonder why, if tractive effort is best with four axles on heavy rail, then why have six in the first place? With a tractor-trailer if the axles are not needed for weight distribition they are raised of the road. Is this the same concept?

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Posted by beaulieu on Thursday, October 01, 2009 11:57 AM

aut1rml

I am looking for information on the workings of the traction control of the ES44C4. The mechics of the system rather than electronic. From the looks of the picturers that I have seen it looks very basic, somehow the air cylinders via linkage piviot a device to unload the axle. How does this work? It also seems to me that just shuting off power to a traction motor on a given axle to save fuel would cause quite a bit of drag.  Reverse gear reduction turning a large unpowered motor. It makes me wonder why, if tractive effort is best with four axles on heavy rail, then why have six in the first place? With a tractor-trailer if the axles are not needed for weight distribition they are raised of the road. Is this the same concept?

 

There are only four traction motors on a C4. The four traction motors are capable of providing more pulling power than the wheelslip (traction control) can utilize when the locomotives weight is evenly distributed on all six axles. What GE's system does is take some of the weight off the center axle of each truck and transfers it to the outer axles. With more weight on the outer (powered) axles more torque can be produced without spinning the wheels. You might ask why not build a 4 axle locomotive instead, the answer is that the total weight of the locomotive would be too high, even though some of the weight is transferred off the center axles, contrary to early rumors, the axle isn't lifted off the rails.

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Posted by oltmannd on Thursday, October 01, 2009 12:19 PM
I'll just add that the ES44C4 is really a poor-man's 4 axle AC locomotive - which is the equivalent of a six axle DC locomotive. Trying to get all the components and fuel capacity onto four axles without very high axle loads is not simple, nor cheap... Taking two motors out of an existing 6 axle design is cheap and easy....and quick to market. The difference between the ES44C4 and an ES44C occurs between roughly 8 and 12 mph. If BNSF is using them on trains that are powered such that they don't ever drop below 12 mph on the ruling grade (which is what they are now doing with their six axle DC fleet), the extra two motors are merely dead weight, so why carry them around. The unloading mechanism is for those rare occasions when the train's a little heavier than they figured or one of the other locomotives in the consist is a bit sick. It give a little extra oomph - which may be the difference between getting over the hill or not. It's cheap insurance. If these cost roughly the same as a six axle DC unit, then BNSF saves maintenance money as AC propulsion is cheaper and more reliable than DC.

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Posted by cx500 on Friday, October 02, 2009 9:53 PM

I wouldn't be surprised if the lifting center axle turns out to be a short lived idea.  Surely the added complexity in the truck will result in additional maintenance, a nuisance at best, and it could prove more costly than the savings from fewer traction motors.  The ES44C4 concept could instead continue using a more standard truck.  Just my thoughts - it will be interesting to see how they work out in the longer term.

John

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Posted by edbenton on Saturday, October 03, 2009 8:50 AM

I have seen then in service.  All GE did was add one extra Air Brake Cylinder and one Bellcrank and 2 rods to reach the crank and axle per side of the truck.  What happens is when the computer thinks the engine needs the Tractive Effort it applies air to the Cylinder and via the bell crank it pushes up on the axles compressing the suspension for that middle axle.  It transfers 25% of the weight of the axle to the other 2 in the truck and boosts the TE of the unit til about 15 MPH then releases the air and lowers the axle.  There is no control in the cab and if there is a fault it will not work.  BNSF is reporting the same power aviablity as the standard GEVO. 

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Posted by bogie_engineer on Saturday, October 03, 2009 7:06 PM

edbenton

It transfers 25% of the weight of the axle to the other 2 in the truck ...

I have looked for information on how much weight is transfered but have been unsuccessful until I saw this.  Is this an official number from GE or someones' estimate?

Dave

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Posted by edbenton on Saturday, October 03, 2009 7:45 PM

From talking to a couple of people I have at the BNSF in the Mechnical Department.  That is what GE's Engineers thinks it transfers plus that would be about the max for Axle loading on the engine based on the Published Weight and max Axle loadings allowed.

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Posted by CAZEPHYR on Saturday, October 03, 2009 7:51 PM

oltmannd
I'll just add that the ES44C4 is really a poor-man's 4 axle AC locomotive - which is the equivalent of a six axle DC locomotive. Trying to get all the components and fuel capacity onto four axles without very high axle loads is not simple, nor cheap... Taking two motors out of an existing 6 axle design is cheap and easy....and quick to market. The difference between the ES44C4 and an ES44C occurs between roughly 8 and 12 mph. If BNSF is using them on trains that are powered such that they don't ever drop below 12 mph on the ruling grade (which is what they are now doing with their six axle DC fleet), the extra two motors are merely dead weight, so why carry them around. The unloading mechanism is for those rare occasions when the train's a little heavier than they figured or one of the other locomotives in the consist is a bit sick. It give a little extra oomph - which may be the difference between getting over the hill or not. It's cheap insurance. If these cost roughly the same as a six axle DC unit, then BNSF saves maintenance money as AC propulsion is cheaper and more reliable than DC.

 

I believe you are correct about the new units being a poor man's 4 axle locomotive that is equal to a DC model with six motors.   These units were purchased to be used on stack trains that require more HP at higher speeds.  Having four axles with 4400 HP allows up to 1100 HP for each axle which does not lend itself to drag service even with the extra weight that can be transferred up to 12mph or so. 

Three of these on a stack train on the transcon could conceivably replace four of the regular 4400 HP six axle units since high speed is the name of the game.  Remember the reason the UP wanted the 6000HP six axle models, it was to use on high speed trains where the HP makes the difference.  

They have been spotted on every type of service so far, but the real use might be to replace the 8-40BW units which had 4000 HP for four axles.  These units were used on the stack trains for many years. 

CZ

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Posted by oltmannd on Sunday, October 04, 2009 9:14 AM
CAZEPHYR
Remember the reason the UP wanted the 6000HP six axle models, it was to use on high speed trains where the HP makes the difference.  
When UP et. al. were considering 6000 HP AC units, the goal was a universal replacement for 4000 HP DC units. HP for HP and #TE for #TE, they'd replace the the DC units 2 for 3. Two 6000 HP AC units would be able to take most any train currently operated.

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Posted by creepycrank on Sunday, October 04, 2009 3:01 PM
I wonder what the relative cost of two 6000 hp locomotives are compared to three ES44C4's?
Revision 1: Adds this new piece Revision 2: Improves it Revision 3: Makes it just right Revision 4: Removes it.
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Posted by timz on Sunday, October 04, 2009 3:08 PM

CAZEPHYR
Three of these on a stack train on the transcon could conceivably replace four of the regular 4400 HP six axle units

The A1A-A1As could conceivably pull 33% harder than a DC C-C? Why would they?

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Posted by CAZEPHYR on Sunday, October 04, 2009 5:01 PM

timz

CAZEPHYR
Three of these on a stack train on the transcon could conceivably replace four of the regular 4400 HP six axle units

The A1A-A1As could conceivably pull 33% harder than a DC C-C? Why would they?

The way I understand the deal is, the higher HP per axle equals higher HP at speed for stack trains.  The A1A would not lug better than a C truck unit, but would have better higher speed pull.  More HP per axle is needed for trains at higher speeds, but is a disavantage on a heavy train at slow speeds.   I have not heard or seen any more orders except for the 25 units.  Does anyone know if the C4 units are working out OK?? 

 As far as using three instead of the four units, this is an example of AC versus DC power and the fact the AC will lug better than a DC model.  I do not know if the testing has been sucessful or not.  GE had a commercial about the new AC model and the fact it had a twenty some percent fuel savings over the DC model.  I had not heard that sales pitch until the commercial.   It would seem the big advantage for the new units is the AC motors and fuel savings.  In practice, I doubt three will replace four units since they are all the same horse power just distributed over a different amount of axles.  

The old 8-40BW models used to be used on stack trains the first ten years of their service life, but usually had five units on the train.    The 500 series 8-40BW were DC models rated at 4000 hp like the 8-40CW's at that time.  

 

CZ

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Posted by edbenton on Sunday, October 04, 2009 5:58 PM

From the Scanner chatter I hear helps being 2 blocks from the Transcon the Crews LOVE THEM.  However they were part of the GEVO turbo issue and were down while those were replaced.  Now they are coming back online and are being used bigtime.  Just yesterday saw the big 10K footer that they run come thru with 4 on it 2 on the head end and 2 pushing.  Since right now Streator is a slow zone due to track work the BNSF was replacing both the NS Diamond and the RT 18 crossing they were only giving the trains 15 MPH til they hit 12th St on the south end of town.  Lets just say I got to see them pull out and I could have sworn I was watching a set of SD-40-2 pulling this thing the way they accelarated.  When they left the restriction they were at 15 when they hit the Next detector they were at 50 in 2 miles.

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Posted by BNSFwatcher on Sunday, October 04, 2009 6:44 PM

Well, most male dogs (not counting silly poodles or stupid Chiahuahuas) lift an axle when they want to better distrubute their body weight.  The jury, methinks, is still out on the ES44C4s.  One came thru here the other day, but I didn't pick up the 6600 number on the scanner in time, ergo no photo.  6609 was leading a mixed lash-up with Dash 9-44CWs.  I figured most of them would be down on the "Transcon", but they are up here, on the "Hi-Line", too.  Also, there are two  pistons, on each side of the truck to lift the idler axle.

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Posted by JayPotter on Sunday, October 04, 2009 7:07 PM

oltmannd
The unloading mechanism is for those rare occasions when the train's a little heavier than they figured or one of the other locomotives in the consist is a bit sick. It give a little extra oomph - which may be the difference between getting over the hill or not. 

Another ES44C4 feature that may help in this kind of situation is the ability of each of its traction motors to produce a maximum of 36,000 pounds of tractive effort, rail conditions permitting, as opposed to the 30,000-pound maximum that each motor on a standard ES44AC can produce.

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Posted by timz on Sunday, October 04, 2009 7:59 PM

CAZEPHYR
The way I understand the deal is, the higher HP per axle equals higher HP at speed for stack trains.

Think the A1A-A1As would pull even better if we removed another motor on each truck?

Probably you'll agree there's no reason to expect the A1A-A1A to exceed 4400 hp at any speed-- right? So you're figuring the C-C can't produce 4400 hp at, say, 60 mph? Why not?

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Posted by CAZEPHYR on Monday, October 05, 2009 8:23 AM

timz

CAZEPHYR
The way I understand the deal is, the higher HP per axle equals higher HP at speed for stack trains.

Think the A1A-A1As would pull even better if we removed another motor on each truck?

Probably you'll agree there's no reason to expect the A1A-A1A to exceed 4400 hp at any speed-- right? So you're figuring the C-C can't produce 4400 hp at, say, 60 mph? Why not?

I think we are talking about two different types of pull on a train.  The first being starting a heavy train and the second keeping it rolling at higher speeds above 60mph.   The reason the old E units used two motors and generators for only four powered axles was to provide higher HP at speed to each traction motor.  Both types of GE units have 4400 total HP available at any speed.  The six axle traction motored units will pull out drawbars quicker than a four axle unit, no doubt.    


It is only a theory that GE and the BNSF is trying and it might not be the correct solution to the BNSF Transcon trains.  

CZ

 

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Posted by JayPotter on Monday, October 05, 2009 8:57 AM

CAZEPHYR
Compare these units to the GE 6000 HP units that the UP and CSX purchased.  The 6000 HP units had 1000 HP available to each axle and that did not work out so well.

What problems were caused by the AC6000CW''s 1000-hp/axle?

 

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Posted by CAZEPHYR on Monday, October 05, 2009 10:41 AM

JayPotter

CAZEPHYR
Compare these units to the GE 6000 HP units that the UP and CSX purchased.  The 6000 HP units had 1000 HP available to each axle and that did not work out so well.

What problems were caused by the AC6000CW''s 1000-hp/axle?

 

The CSX has programmed many of their 6000 HP units back to 4400HP using software to reduce the HP.  I am not aware if all have been reprogrammed, but it is a work in progress. 

CZ

 

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Posted by carnej1 on Monday, October 05, 2009 11:31 AM

CAZEPHYR

JayPotter

CAZEPHYR
Compare these units to the GE 6000 HP units that the UP and CSX purchased.  The 6000 HP units had 1000 HP available to each axle and that did not work out so well.

What problems were caused by the AC6000CW''s 1000-hp/axle?

 

The CSX has programmed many of their 6000 HP units back to 4400HP using software to reduce the HP.  I am not aware if all have been reprogrammed, but it is a work in progress.  The original plan was to use two of the 6000HP units in place of three to four older diesels units depending on the requirements of the train.   I don't know all of the problems, but 6000HP seemed to cause more problems than it was worth.   The weight of the 6000HP diesels was almost the same as the 4400HP models, about 420,000 lbs.  This probably made them slippery when starting heavy trains.   I read recently that ballast is being added to some of the CSX 4400 HP units for heavy train service. 

The 6000 EMD units that the Union Pacific leased were junked.  The new motor for the EMD 6000 HP units seemed to be part of the problem and EMD wanted out of the railroad business so they never really perfected the 6000HP product.  

 

CZ

 

 I have read that a number of the derated AC60s have been "re-rated" to 6,000 HP when the new Gevo diesel engines were installed. Both GE and EMD are still actively building 6,000 HP prime movers for China (and Brazil in the case of GE). Maybe they can work the bugs out, maybe not...

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Posted by JayPotter on Monday, October 05, 2009 11:32 AM

CSXT's AC6000CWs are currently rated at 6000 horsepower; and the prior horsepower reductions were unrelated to adhesion problems.  The only CSXT AC6000CWs that weigh 420,000 pounds are the three pre-production units.  The other 114 units weigh 432,000 pounds. I expect that if those units actually were slippery when starting trains -- or under other circumstances -- CSXT would solve that problem by updating their adhesion-management software.  They are still operating with their original software, which is several versions older than the version being used on the ES44C4s. 

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Posted by oltmannd on Monday, October 05, 2009 12:15 PM
CAZEPHYR
Almost any diesel has the starting TE to start a large train today on level track, but to keep it rolling at 70mph or so requries higher HP per axle. 
No. You have it exactly backwards. More powered axles = starts bigger train. (all other things being equal) Total HP = max speed. The number of powered axles is irrelevant.

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Posted by timz on Monday, October 05, 2009 4:14 PM

CAZEPHYR
The C4 has 1100 HP per axle compared to 750 HP per axle for a normal six axle unit.   The larger amount of HP per axle gives the traction motor higher power at the upper limits in revs, which relates to speed.

So at 70 mph an ES44C4 would pull even better if we cut out two of its four motors, giving it 2200 HP per axle?

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Posted by CAZEPHYR on Monday, October 05, 2009 4:51 PM

timz

CAZEPHYR
The C4 has 1100 HP per axle compared to 750 HP per axle for a normal six axle unit.   The larger amount of HP per axle gives the traction motor higher power at the upper limits in revs, which relates to speed.

So at 70 mph an ES44C4 would pull even better if we cut out two of its four motors, giving it 2200 HP per axle?

 

You could probably email GE and get more information that is factual about the new units if you wanted to find out how they work.  

 The information below is from the GE page.

CZ 

 

 Press Release
GE Transportation Unveils New Evolution® Series Locomotive
U.S.-manufactured locomotive is GE’s latest ecomaginationSM product; Reduces fuel
consumption by 17% and emissions by 70% vs. existing DC locomotives
Erie, Penn. (May 18, 2009) – GE Transportation, a unit of GE (NYSE: GE), announced today that it has
introduced the newest line of fuel efficient and low emissions Evolution® Series locomotives, the Model
ES44C4. The new model, which is part of GE’s ecomaginationSM environmental program, delivers a
cleaner, faster, safer and more reliable alternative to the aging North American fleet of DC-powered
locomotives. GE is building the new locomotive at its Pennsylvania manufacturing plants in Erie and
Grove City.
“Railroads helped build this country, and this locomotive is proof that manufacturing and heavy
industry can deliver the innovation that will drive economic growth,” said Lorenzo Simonelli, President
and CEO of GE Transportation. “This latest Evolution Series locomotive is an industry breakthrough,
delivering a modern and efficient AC locomotive that replaces the older, less fuel efficient and less
emissions friendly, DC-powered models. It also provides a direct replacement option for the current six
axle, 4400 HP locomotives being delivered today.”
Added Simonelli: “By introducing advanced technology that requires less maintenance, reduces fuel
consumption and lowers emissions, we are providing our North American customers with an
opportunity to upgrade their aging fleet with better performance – both on the rails and for the
environment.”
The new Evolution Series locomotive delivers significant performance improvement over existing DCpowered
locomotives in three key areas:
·  Better environmental performance – Compared to older DC locomotives, Model ES44C4 uses
up to 17 percent less fuel and reduces emissions by approximately 70 percent. Six hundred of
GE's latest locomotives can displace up to 800 older locomotives, translating to an annual
reduction of more than 70 million gallons of fuel – the equivalent of taking 115,000 cars off the
road for a year. The overall annual emissions reduction from this displacement is estimated to
be 48,000 tons of nitrous oxide; 1,500 tons of particulate matter; and 1.0 million tons of carbon
dioxide, a major greenhouse gas.
·  Advanced technology – Model ES44C4 delivers sophisticated traction control technology with
its patented Dynamic Weight Management System that continuously monitors traction at the
axles and automatically adapts to maximize performance on heavy trains. This system –
similar to traction control on an automobile – limits wheel slip at start up, on inclines and in
2
adverse weather conditions, ensuring optimum performance and less wasted energy.

In addition, this latest Evolution locomotive has a higher top speed than traditional DC-powered locomotives.

 

·  Greater reliability – Older, DC heavy-haul locomotives currently require frequent and
expensive maintenance to keep them running, which translates to significant time off the
tracks instead of hauling freight. GE’s new AC motors have fewer parts to maintain and
eliminate the electrical problems that hamper DC motors. As a result, they are easier to
maintain and provide a higher level of reliability, which will allow the new ES44C4 to spend
more time on the rails instead of in the shop for maintenance and repairs. Ultimately, this new
platform could replace the older generation of DC-powered locomotives in hauling our nation’s
freight.
BNSF road test
Burlington Northern Santa Fe Railway is the launch customer for this new model, and recently took
delivery of 25 locomotives. Chris Roberts, BNSF Vice President of Mechanical and Value Engineering
said, “We are putting these locomotives through rigorous testing to determine the benefits of this new
AC alternative, and the early results have been positive.”
Evolution Series Locomotive
The Evolution Series Locomotive, launched in 2002 and introduced into revenue service in 2005,
represents a $400 million investment by GE over eight years. GE Transportation recently celebrated
the delivery of its 3000th Evolution Locomotive, a milestone validating this leading global platform.
The Evolution Series Locomotive is 5% more fuel efficient and generates 40% lower emissions than
previous locomotives. It saves approximately 300,000 gallons of fuel over its lifetime. In addition, the
Evolution Series Locomotive is more than 6% more fuel efficient than GE’s closest competitor in North
America as validated by a nationally recognized, independent research institute in March 2009.
The Evolution Series Locomotive is one of GE’s most prominent ecomaginationSM products.
Ecomagination is a GE-wide initiative to help meet customer demand for more energy-efficient
products.
Evolution Series Locomotives currently are operating in the United States, Canada, Mexico, Brazil,
China, Mongolia, Australia, Kazakhstan and Egypt. Approximately 17,000 GE locomotives are in use in
more than 50 countries around the world. GE Transportation’s Evolution Series success story serves as
a powerful reminder that free trade and open markets worldwide sustain businesses and employment
opportunities in North America and beyond.
About GE Transportation
Established more than 100 years ago, GE Transportation, a unit of General Electric Company (NYSE:
GE), is a global technology leader and supplier to the railroad, marine, drilling, and mining and wind
industries. GE Transportation provides freight and passenger locomotives, signaling and
communications systems, information technology solutions, marine engines, motorized drive systems
for mining trucks and drills, high-quality replacement parts and value added services. GE
Transportation is headquartered in Erie, Penn., and employs approximately 10,000 employees
worldwide. For more information visit www.getransportation.com.

 

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Posted by timz on Monday, October 05, 2009 6:46 PM

CAZEPHYR
the four traction motors on the C4 can use more HP and give a higher torque for those motors at speed than the same HP distributed over six motors.

That thinking would apply at any speed, not just 60+ mph. Do you think an A1A-A1A outpulls a C-C at, say, 20 mph? 

CAZEPHYR
GE believes this and so did the BNSF

Hopefully they're not that dumb. Has either of them ever claimed the A1A-A1A would outpull a C-C?

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Posted by oltmannd on Monday, October 05, 2009 8:33 PM
timz

CAZEPHYR
the four traction motors on the C4 can use more HP and give a higher torque for those motors at speed than the same HP distributed over six motors.

That thinking would apply at any speed, not just 60+ mph. Do you think an A1A-A1A outpulls a C-C at, say, 20 mph? 

CAZEPHYR
GE believes this and so did the BNSF

Hopefully they're not that dumb. Has either of them ever claimed the A1A-A1A would outpull a C-C?
The A1A ES44C4 will pull EXACTLY THE SAME as the C trucked ES44AC at all speeds from roughly 12 mph to 70 mph. No difference. Zero. Nil. Nada. BNSF and Timz know this.... Everyone else, back to Physics 101!

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Posted by GP40-2 on Monday, October 05, 2009 10:53 PM
CAZEPHYR

I think we are talking about two different types of pull on a train....

So how many different ways can a locomotive pull on a train? 2? 5? 18? 100?

CAZEPHYR

Almost any diesel has the starting TE to start a large train today on level track, but to keep it rolling at 70mph or so requries higher HP per axle.  The same 4400 HP for the C4 as the regular DC model increases that HP per axle for a four unit model by a large amount.  The C4 has 1100 HP per axle compared to 750 HP per axle for a normal six axle unit.   The larger amount of HP per axle gives the traction motor higher power at the upper limits in revs, which relates to speed.

What??? That is absurd. No more video games for you until you have completed your physics homework.

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Posted by JayPotter on Tuesday, October 06, 2009 5:27 AM

I hesitate to make this discussion any more complicated than it already is; but I think that the issue on CAZEPHYR's mind relates more to speed than to tractive effort.  To me, he seems to be (1) wondering why the four-motor 4400-hp ES44C4, which has the same gearing as six-motor 4400-hp EVOs, has a maximum speed rating of 75 mph instead of the 70-mph rating that seems to be standard for six-motor EVOs and (2) attributing that difference to the fact that the ES44C4 has more per-motor horsepower.

I wonder if there's a difference in speed rating because at high speeds four motors produce less counter-electromotive force than six motors produce?

 

 

 

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Posted by oltmannd on Tuesday, October 06, 2009 7:20 AM
JayPotter
I wonder if there's a difference in speed rating because at high speeds four motors produce less counter-electromotive force than six motors produce?
You noted that the max TE per axle is higher, too. So, could it be motor design. But, I'd bet it's because the ES44AC is generator-limited. The motors and inverters can take more than 1/6th of the generator output, so increasing the per motor max TE 20% is within the design limit of the motors and inverters As for the speed, I'm pretty sure back EMF is not an issue, but to get to a higher speed, the inverter has to output a higher frequency, so it could be the inverter design. Or, perhaps, they are just pushing the limits on the existing design a bit, perhaps balancing the squirrel cage to a tighter tolerance.

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Posted by JayPotter on Tuesday, October 06, 2009 8:11 AM

The ES44C4 and ES44AC use the same model traction motor.  I suppose that some modifications might have been made within that particular model; however the 36K TE limit wouldn't necessarily indicate that.  That limit, which is intended to prevent excessive mechanical stress, is software-imposed, just like the standard 30K limit. 

The reason counter emf came to mind is that I was once told -- and I think it was in a discussion related to the ES44C4 -- that one western railroad -- I don't recall which one -- which operated SD40s or SD40-2s in high-speed service had a practice of cutting out one traction motor on each truck in order to increase speed by reducing counter emf.  Being more interested in tractive effort than speed, I didn't pay as much attention to that part of the discussion as I probably should have.

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