GE evolution with 4 traction motors instead of 6

minesweeper Nov 28, 2017

  1. minesweeper

    minesweeper TrainBoard Member

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    Reading wikipedia i noticed
    The ES44C4 (Evolution Series, 4400 HP, C-C wheel arrangement, 4 traction motors) was introduced in 2009. While similar to the ES44AC, the ES44C4 has two traction motors per truck, instead of the conventional three such as on the ES44AC. The center axle of each truck is unpowered, giving an A1A-A1A wheel arrangement.
    Not being so familiar with american practice I wonder why does a Railroad (BNSF was the launch customer according to wikipedia) prefer a A1A-A1A to a C-C arrangement, as long as I know the standard, by deliberately reduce the weight that is used for traction (having all the rest of the locomotive equal, including prime mover and total weight).
     
    Kurt Moose likes this.
  2. Kurt Moose

    Kurt Moose TrainBoard Member

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    Actually, when you lift the center idler axle on these units, it puts more weight on the powered axles for more traction.
    Designed more for traction than speed, these can usually be found on coal trains and unit oil trains of the time, for weight is more of a factor than speed.
     
  3. YoHo

    YoHo TrainBoard Supporter

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    Kurt, that is not as I understand it, true and I don't believe the C4s spend much time on Coal trains (though never say never, BNSF certainly will use them if that's what's available.) They were built for Intermodal trains on the transcon pure and simple. Coal trains want the traction advantages of 6 motors. A standard 6 motor AC GEVO has more tractive effort than a C4 gevo.

    BNSF wanted to standardize on AC locomotives going forward. They were a large purchaser of the Dash-9 in particular for their fast intermodal trains. They wanted an AC engine that gave approximately the same characteristics as a a DC motored Dash-9...AND they wanted to reduce the costs of the AC units to be more in line with the Dash-9 pricing.
    Hence, remove a motor per axle giving you higher HP per traction motor (more speed).
    You may ask, why not simply build a B-B unit. The answer is that the weight of a modern Tier 3 (and even more so a Tier 4) Freight locomotive is so high that it would be impossible to have it riding on a B-B truck arrangement without destroying track left and right.
    The movable center axle allows them to put more weight on the power axles without completely removing weight on the center.

    EMD has produced prototypes in both the Tier 3 SD70ACe and the newer Tier 4 SD70AC where there are only 2 powered axles per truck, but whereas the GE uses A1A, the EMD has the inboard axle unpowered making it a B1-1B arrangement. They do not have the lifting mechanism as they didn't see as they needed it.

    I'm not sure if BNSF has purchased any of the EMDs or has just bought straight six motor versions.
     
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  4. minesweeper

    minesweeper TrainBoard Member

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    Yes, but why do not buy a six motors unit that has all the weight on the drivers, instead of a 4 motors with two idle axles?
     
  5. YoHo

    YoHo TrainBoard Supporter

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    1: It costs less
    2: They value speed over traction and more HP per motor equal's more speed.

    Basically, if BNSF could buy a 4 axle unit with 4400HP for use on Transcon trains, they would.
     
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  6. acptulsa

    acptulsa TrainBoard Member

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    Re-read YoHo's informative post. Basically, four AC traction motors cost as much as six DC motors and a rectifier.

    Also remember that you see many photos of the BNSF in scenic mountain territory, but well more than half their track is on the Great Plains, the Breadbasket of the World, where grades are anything but severe. The GN, BN and Santa Fe always had two or three Pacifics for every Mountain type back in the day.
     
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  7. ddechamp71

    ddechamp71 TrainBoard Member

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    Indeed, ES44C4's tractive effort curve is close to good old Dash9's (at least when there aren't any dead leaves or frost on railheads)...With 4 traction motors which is cheaper than 6. I've even read that BNSF Dash9s are beeing retrofitted into ES44C4s.

    Dom
     
  8. YoHo

    YoHo TrainBoard Supporter

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    BNSF tried one as I understand it, but they haven't gone further. Norfolk Southern on the other hand is converting a large portion of their dash 9 fleet to AC. They're going with 6 traction motors though.
     
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  9. ddechamp71

    ddechamp71 TrainBoard Member

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    Ok, I must have misread about that conversion....

    Dom
     
  10. YoHo

    YoHo TrainBoard Supporter

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    There was a lot of strum und drang about it some time back, but BNSF never pulled the trigger. Not sure exactly how many were made. Might be more than one. They are rebuilding the SD70MACs in kind...NS is trying to avoid buying Tier IV units. They are also having EMD convert their SD70s to AC.By the way the official name for the rebuilt Dash 9s is AC44C6M C4M if it only has 4 traction motors.
     
  11. acptulsa

    acptulsa TrainBoard Member

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    I'll never understand why Dubya pushed through emissions regulations for locomotives. It was stupid. Railroads are the cure for air pollution, not the cause. They move so much freight on such a small amount of fuel, compared to trucks, that they pollute less just by being efficient.

    I know the Tier IV units use more fuel, and Dubya never once failed to pass a regulation, veto a law, or start a war if his oil company would benefit. But punishing the railroads for being the cleanest and greenest way to ship freight was stupid, even by the standards of tihe guy who stood next to Queen Elizabeth and said that was the first time she visited since 1776.
     
  12. ddechamp71

    ddechamp71 TrainBoard Member

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    So some of these are converted to full 6 traction motors AC units ?

    Dom
     
  13. acptulsa

    acptulsa TrainBoard Member

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    There aren't many of the A1A-A1A units--maybe only one. They're converting DC-motor C-C units--Dash Nines--to AC motors.
     
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  14. YoHo

    YoHo TrainBoard Supporter

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    No no,

    ON BNSF
    there are over a thousand of the A1A models.

    ON BNSF There is only 1 DC to AC conversion BNSF #616
    It is also an A1A

    NORFOLK SOUTHERN is doing the major DC to AC conversion.

    All of the NS rebuild units are full 6 traction motor units


    As for the Tier 4 rules.
    You're over simplifying things. There's a very very good case that the Tier 4 standards were not very practical and had they adjusted their carrots and sticks, they could have done a better job of achieving their goals, but that's not to say their goals were invalid.
    The standards result in higher fuel utilization, because the specs are there to increase economy or reduce CO2, they're there to reduce NOX and particulates.

    I live 2 miles from the Roseville California yard one of the places in California that is a focus for Diesel exhaust issues. On a hot summer day, that Yard creates Air quality nightmares that I can attest to. So I know just what the Diesel exhausts of locomotives can do.
     
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  15. acptulsa

    acptulsa TrainBoard Member

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    Thanks for the correction. So the A1A units versus the conversions are two different railroads reacting to the same sitution.

    As for Tier IV, I'm not saying that locomotives don't pollute, or that I don't agree that carbon monoxide, sulphur oxides and nitrous oxides are worse than carbon dioxide, which at least plants like.

    I'm just saying that even if great lengths are taken to clean up truck emissions, and no effort is made to clean up locomotive emissions, trains (with their steel wheels and steel rails) naturally pollute far less than the number of trucks it takes to haul the same tonnage (which is quite a lot of trucks). The big picture is, when it comes to air quality overall, railroads are the solution, not the problem.

    But, no, that does not mean I go out of my way to spend time downwind from a busy yard. That said, if a yard is situated in topography which blocks the wind, that seems like something local ordinance should take care of. Certainly the yard engines do the most belching most of the time in that one spot.

    It's not that I think locomotives should belch toxic fumes. It's just that driving rail shipping rates up across the board is an incredibly stupid way to address the issue of air quality. You don't improve a nation's air by making trucking more competitive with rail. That is a simple equation.
     
    Last edited: Dec 1, 2017
    badlandnp likes this.
  16. ddechamp71

    ddechamp71 TrainBoard Member

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    If you could manage to make french politicians, civil servants and business CEOs take this into account.... :(

    Dom
     
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  17. Hytec

    Hytec TrainBoard Member

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    Likewise in the USA. At least the French government is maintaining SNCF as an equal public transport, and adequately funding Research and Development.
     
  18. YoHo

    YoHo TrainBoard Supporter

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    Well, but The Truck Tier IV restrictions are even worse than those for Rail. So it isn't really driving up costs compared to trucking. And trucks can't get around the rules through rebuilds.

    In either case, Rail shipments have been down due to the free fall in coal loads. It's been up from the bottoming out this year, but not nearly enough and unless something serious changes in the natural gas price, Coal will never recover. Regardless of what any politician might say. It's never going to be what it was.

    In fact, it's been rough for GE and EMD, because sales are off not just because of Tier IV, but because there are simply surplus engines on the system due to loss of traffic.
     
  19. ddechamp71

    ddechamp71 TrainBoard Member

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    SNCF is by no way the mean to keep freight trains running.

    SNCF's bord of directors is only interested by one goal : running TGVs (passenger bullet trains). If they could drop everything else, they would do it. And speaking of railroad freight spinning down in France, there has been simply one determinant point : abandonment by SNCF of single carload in 2007. Thus a vast majority of companies relying on rail until then shut down their private spurs and switched to trucking.

    One of the problems is that railroad network still belongs to SNCF, and this entity doesn't want to keep it easy for other railroad companies to take over what it dropped. That's why rates to run trains on SNCF network are kept unreasonably high (gvt says nothing about that) and private railroad companies don't want to bother with single carload.

    So, every year, hundreds of miles of small lines are shut down, serving industries that now rely on trucks that now invade neighbouring highways.

    And indeed, when now in France you're lucky enough to spot one of the scarce remaining freight trains, these are always block trains. Nowadays, here in France, railroad freight traffic (tons x miles) is only 9.5% of the total carried freight, vs 85% for trucks. That's the absolute European Union's worst figures. 20 years ago, figures were in the 20/75 range... SNCF doesn't care (or worse, even applauds), government and administration don't care, and citizens don't care even when at the wheel of their automobile they are stuck on a truck congested highway. The only people arguing against that are maybe some small business's managers who dropped their spurs, because they have numbers in their heads even those dealing with artificially boosted trucking business, but they have their business to run and they have no other choice than to go to the best economy/efficiency rate. Provided they have choice between more than one mean of transportation (ie trucks)...

    One of other problems here in France is most people's mind, including those who make this mind, politicians, civil servants, medias, etc. For them, trains are only made for one thing : carrying passengers. When some SNCF line is shut down, temporarily (strikes, technical issues...) or definitely, the only question most people, including french railroad oriented railfans have in mind is "Oh, how will people travel on this sector now ?".

    In my opinion, one of the way to reverse that shocking trend would be "shortlining" SNCF's abandoned railroad lines, a little bit like what you guys have in the US. But for the time beeing this way remains mostly forgotten, as there is no will for that among public and private mind.

    Sorry guys for beeing that long, and if you want let's revert to more interresting ways to run railroads, for example the american one... ;)

    Dom
     
    Last edited: Dec 2, 2017
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  20. Hytec

    Hytec TrainBoard Member

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    Dom, thanks for that explanation. That kind of information never makes it across the ocean, only the "Gee Whiz" of the latest TGV development. The US used to have many private spurs for single carloads 50-70 years ago. Now each time I ride through both metro and rural areas, I see private spurs going off into weeds and trees. The facilities may still be operating, but the loading docks, etc., have been remodeled for trucks.
     

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