GDRMCo NS also already tested the ES44C4s and haven't gone back, would suggest people take this also into account before thinking the hilly profile of the NS network is suitable for a locomotive with unpowered axles.
NS also already tested the ES44C4s and haven't gone back, would suggest people take this also into account before thinking the hilly profile of the NS network is suitable for a locomotive with unpowered axles.
NS has much tamer ruling mainline grades than CSX, UP and BNSF.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
GDRMCoThere's no point to spend the money going thru the DC to AC rebuild if there's no performance gain.
Performance is only part of the equation.
Cost to own and maintain is a big chunk, too. Way back when, when AC units were first being thought about, it was estimated that about half the benefit was performance (reduction in number of units) and the other half was maintenance cost (inverter + AC motors << DC motors) DC motors were (and remain) the 900# gorilla of locomotive maintenance cost.
ML
YoHo1975Why does UP only buy AC when DC will work fine on non-Unit trains? Same for CSX? Why did BNSF switch to 4 motor AC vs. 6 Motor DC? what are the financial incentives?
It's the service requirments and line profile that determine what locomotive fits best. First, you figure what HP/ton you need to get from A to B in the time required. Then you figure how much max TE you need to get up and over the ruling grade w/o stalling. You can do this for each line and class of service. Then you have to look at the trade-offs between having a segregated fleet vs a universal fleet. If you have widely disparate requirements, and there exist advantages for buying a disparate fleet to meet those needs, then a segregated fleet might make sense.
UP pretty much gave up dispatching by HP/ton and power everything at drag ratings. BNSF has not done this. That is why BNSF is buying four motor locos and UP is not.
Leo_AmesWe're back to what's proof positive for why this isn't going to happen. They're not going to spend thousands on perfectly good power just to rebuild them into A1A's with AC traction motors with performance essentially where it was at before the rebuild.
They will if reduced maintenance and improved reliability pay for the capital investment.
No problem, upon rereading, I wasn't being as clear as I could have.
Sorry, I interpreted what you said to saying that the price for AC had gotten so competitive that they were essentially equal for why these models disappeared. I didn't realize that you essentially said that they had placed a tariff on DC orders to discourage orders.
But upon rereading it through, I clearly misinterpreted.
Isn't that what I just said?
GE raised their price on the DC units right around when the C4 was introduced to encourage DC purchasers to go for the C4. They'd still be happy to build you a ES44DC, but you're going to pay a premium for a special order which defeats why you'd want to buy it over a ES44AC in the first place.
GE essentially just wants to produce one locomotive line, not two. The C4 variation on the ES44AC is their solution.
As for why others stopped buying DC earlier, there's a multitude of reasons. Seeking universal power for one as the AC premium continually has dropped since the SD70MAC and AC4400CW were introduced, some because of large late DC orders like Union Pacific's huge fleet of modern SD70M's, rebuild programs to create 21st century DC power in-house at Norfolk Southern instead of buying new, Canadian National regularly dipping into used power by picking up lease expired late model EMD's and GE's, etc.
Wouldn't be surprised if a few motive power officials at big lines are just playing the waiting game as well to see where the C4 model goes and waiting on the verdict for EMD's reply.
I thought GE had made the AC units cheaper than the DC units, because they want out of the DC game completely and I further thought that EMD had at least matched price on the ACe vs. the M-2.
Parts commonality would be a big savings and training savings.
Why does UP only buy AC when DC will work fine on non-Unit trains? Same for CSX? Why did BNSF switch to 4 motor AC vs. 6 Motor DC? what are the financial incentives?
Clearly, GE and EMD are disincentivizing the purchase of new DC power. They don't want to build it.
Unit trains are not where the growth is, so the odds that they would embark on such an ambitious program for that seems unlikely. There must be other factors.
AC is still a premium of several hundred thousand dollars.
JayPotterPerhaps the lack of other Class 1 sales is less a function of the performance of AC-traction versus the performance of DC-traction than it is a function of the cost of a new four-motor-six-axle AC-traction unit versus the cost of a new six-motor-six-axle AC-traction unit.
There's still a significant difference between an ES44DC and a ES44AC. It's no secret why the C4 was created. It has the performance at least as good as an ES44DC, the extended traction motor life of AC, increased commonality with the AC CC's, and thanks to 4 traction motors and simplifying things for the manufacturer, it's done at the price of an ES44DC.
JayPotterHowever if the railroad can convert a DC-traction unit into a four-motor-six-axle AC-traction unit for significantly less than the cost of a new four-motor-six-axle AC-traction unit, it might decide to try the four-motor technology.
We're back to what's proof positive for why this isn't going to happen. They're not going to spend thousands on perfectly good power just to rebuild them into A1A's with AC traction motors with performance essentially where it was at before the rebuild.
There's no great mystery what they're seeking by considering this. They want AC4400CW style performance out of their C44-9W's now that the advantages of modern AC's have won them over in a big way and they see hundreds of otherwise modern GE's rolling out there that they bought just a short time earlier that aren't as capable as they'd now prefer.
Nothing has been said about a C4 style rebuild program here and there's no apparent logic to suggest that they'd ever even consider such a thing.
GDRMCo What if the cost between a rebuilt 4-motor AC unit and 6-motor AC rebuild is small also? Would make more sense to go with 6-motors than with 4.
What if the cost between a rebuilt 4-motor AC unit and 6-motor AC rebuild is small also? Would make more sense to go with 6-motors than with 4.
It's not small, that's why the C4 exist in the first place. If there wasn't a real savings there over a 6 axle AC, it would have no reason to exist.
If 4 motors was so good for intermodal why has of the Class 1s only BNSF bought them? Surely someone else would have gotten them? CSX hasn't and they use their 4000hp+ AC units on everything and it appears NS will happily do the same. There's no point to spend the money going thru the DC to AC rebuild if there's no performance gain.
There's nothing wrong with DC for the average merchandise train and such. They're not going to make a huge investment in retrofitting a portion of their fleet for AC just for more durable traction motors. It wasn't worth the premium when new and it certainly isn't worth what it would cost to now change that.
If they do this, it's for performance reasons. Increased adhesion, a lower short-time rating, etc. That calls for 6, not 4, traction motors.
GDRMCo They're clearly finding financial savings (fuel, unit utilisation, maintenance) in the AC locos they do have and would like to get that same performance and savings from modifying the DC units that can be modified into AC units. The 4 motors on 6 axle thing won't happen.
They're clearly finding financial savings (fuel, unit utilisation, maintenance) in the AC locos they do have and would like to get that same performance and savings from modifying the DC units that can be modified into AC units. The 4 motors on 6 axle thing won't happen.
But, if they find that using only four motors make the net present value even greater, then it's 4 motors.
The AC units that NS has purchased over the past several years were targeted for unit train service - which is what they are doing, predominently. HP requirments for the bulk of the merchandise network and all of the intermodal network would never use the extra TE you get from 4400 HP six motor AC. Four motors are more than enough. The traffic growth on NS is nearly all on the intermodal side.
However, if it's to finish out an AC fleet for a waning network of unit trains, then it'll be six motors.
What do you propose for the reason that they're considering this if it's not to make them more suitable for mountainous terrain, coal service, and other areas where AC is so advantageous for the modern freight environment?
I believe that we can safely assume why they're considering this.
oltmannd CSSHEGEWISCH AC traction is turning up in a lot of lighter uses. The current order by CTA for rapid transit equipment which is now being delivered includes AC traction motors. I'll bet it is one truck powered and the other not.... GE's first foray into AC power was for transit equipment. In fact, the inverters on their first AC locos were beefed up transit inverters.
CSSHEGEWISCH AC traction is turning up in a lot of lighter uses. The current order by CTA for rapid transit equipment which is now being delivered includes AC traction motors.
AC traction is turning up in a lot of lighter uses. The current order by CTA for rapid transit equipment which is now being delivered includes AC traction motors.
The CTA's current 5000 series cars now being delivered have four AC motors per car.
http://www.chicago-l.org/trains/roster/5000mkll.html
I'm struggling to understand this strange fascination people here have with the C4, NS won't go that route rebuilding the Dash-9s with AC. They'll be chasing ES44AC like performance from the rebuilds not the same performance.
I'd be very surprised to see Norfolk Southern going the A1A route for their rebuilds. Their AC's are as likely to be found on heavy coal trains in the mountains as they are on some manifest on a flat route. Hard to imagine this not being done to create more universal power that's fully at home on any NS mainline assignment.
Why would they spend all that money just to recreate the performance levels they basically already have as-is? That's a lot of money no matter what it ends up actually costing just to be able to enjoy longer traction motor life. There has to be a major performance reason behind their contemplating this program.
The performance of something like the C4, per GE's own statements, is basically roughly that of an ES44DC. The advantages for the purchaser for the C4 over the ES44DC comes from more durable traction motors and increased commonality with the CC AC's which reduces parts inventories and maintenance cost at no extra purchase expense to the buyer over that of an ES44DC.
I bet they're doing this more than anything for the adhesion benefits and slow speed overload capabilities an AC CC has over its DC counterpart. It's the only thing that makes any sense in my opinion. And that calls for 6 AC traction motors, not 4.
oltmannd GDRMCo I would expect it to be a 6 motor for 6 motor DC-AC rebuild, NS has plenty of mountains and the C4s aren't the best on those... NS needs lots of locomotives with 4000-4400 HP and about 100,000# TE. They are a good fit for intermodal and merchandise service. The extra two AC motors would just be extra cost and complexity...
GDRMCo I would expect it to be a 6 motor for 6 motor DC-AC rebuild, NS has plenty of mountains and the C4s aren't the best on those...
I would expect it to be a 6 motor for 6 motor DC-AC rebuild, NS has plenty of mountains and the C4s aren't the best on those...
NS needs lots of locomotives with 4000-4400 HP and about 100,000# TE. They are a good fit for intermodal and merchandise service. The extra two AC motors would just be extra cost and complexity...
Don't know if NS will order any but I did read that the RR "borrowed" a set of ES44C-4s from BNSF to evaluate so maybe they are considering the A-1-A four motor option.
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"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Does anyone know what the starting an continuous tractive effort wil lbe these locomotives?
Thanks
Ira
I suspect that the closest you're going to get to new DC freight power are medium duty roadswitchers like EMD's ECO line or major rebuilds like some of Norfolk Southern's programs. There's no sign that anyone is going to ever start buying new heavy duty 4,000HP + six axle DC's again. The only question is if these four motor six axle AC locomotives take off past BNSF's love affair with GE's C4 or if AC CC's are the future for all road assignments.
DC motors in passenger service are definitely longer lasting than they are in heavy freight service, that's why DC motors have been longer lived for passenger power here although that's starting to quickly change. The adhesion benefits aren't as important nor is the higher short-time rating of AC. The primary advantage of AC for conventional passenger power typically is the higher mean time between failures over DC traction.
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