Western Railroad Discussion > 6000hp Locomotives- What is their future?

When I was in the US last year I did not see any 6000hp locomotives from either GE or EMD.

Are the 4000hp now the standard rather than 6000hp?

Is it like back in the 70s when both builders tried to raise the stakes to 3600hp, but in the end it was 3000hp that became the standard?

For that matter what is the future of the EMD 256H engine?

Regards,
Grahame
AUSTRALIA

In my view, you will continue to see 6000hp locomotives and occasional purchases of new ones. But, as you noticed, they are not mainstream or general purpose power and probably won't be for some years. Their nitch is high speed specialty freight like intermodal and heavy long run trains like Powder River Basin unit coal trains.

For general freight, it looks like the AC and DC SD-70's and C-44's will rule for the near future, at least.

Several reasons are driving this. First, the sad truth is that general freight still moves so slow that the hp demands are quite low except in high-grade territories. Second, rr's are reluctant to assign only one unit to even light trains because of the risk of road failures. Third, the 6000's are not as reliable as the more conservative 4000-4400's and maintenance is more demanding and high-tech (read that expensive!) than before.

All of the above, and probably more reasons that others will cite, allow the rr's to buy the less expensive smaller units for main stream freight service.

Of course, all of the above would change drastically if the rr's were to find a way to pick up the speed of general freight a bit--say, from 8mph average to a radical 15mph or so. But that is wildly optimistic and probably just wishful thinking.

An article on the 6000hp units in Train magazine a few months ago pretty much said what mediumclear posted. Only 1 engine on a train-could break down. Primarily used for coal and the like and just too much unneeded horsepower.

We see quite a few of the GE 6000hp ACs here in Denver, the 7500 series. Burnham (Denver Diesel) is a main servicing shop for them and they are used in coal service on the Moffat. They are also seen and easily photographed in North Yard.

They are also storing 4 of them at Burnham, nothing wrong with them except high fuel consumption so they are not using the entire fleet. I do not kow if they have any others being stored around the UP system.

Paul

mediumclear wrote:

> Of course, all of the above would change drastically if the
> rr's were to find a way to pick up the speed of general freight
> a bit--say, from 8mph average to a radical 15mph or so. But
> that is wildly optimistic and probably just wishful thinking.

I'm curious what the basis of that 8 mph average is. Does it only
take into account trains that are actually on the road, or is it the
average velocity of freight cars including when they are sitting
around in the yard or being shoved over the hump at 1.5 mph?

I agree with all other post regarding the future of 6000 hp units. At this point the GE AC44/C44-9W combo and the EMD SD70MAC/SD70M combo are about as good as it gets when it comes to reliability. As for the future of the EMD 265H prime mover, you have to remember that when Tier 2 emission requirements start in 2005, it is highly unlikely that the 2 stroke 710 prime mover used in the SD70MAC/SD70M will meet these requirements. So whether EMD likes it or not, the future for EMD will be the 265H prime mover or a 12 cylinder version of the same block to meet the 4000-4400 hp demand from the RR's. On a side note, the GE 7FDL and 7HDL will both likely meet Tier 2 requirements, meaning GE will definitely have an advantage going into 2005 will already proven prime movers.

AaronJ

Will EMD still be around in 2005???

JF

Can someone clarify for me the difference(s) between the MAC and M designations on the SD70's and SD90's.

I know it refers to AC (alternating current) traction motors vs DC (or a least I think I do), but why is one used instead of the other?

Is there an easy method (besides the ID marks on the cab) to identify the difference?

Do all current GE's have AC traction motors?

Finally and excuse my ignorance, the traction motor is the device that actually turns the wheels, right? I mean this isn't an additional device that say a GP38 or 40 doesn't have?

Thanks.

GE does still produce locomotives with DC traction motors. The most well known is the C44-9W. The AC44 is essentially a C44-9W but with AC traction motors. The same thing can be said between the SD70MAC and SD70M that EMD produces. The only real meaning between M vs MAC on EMD locomotives is the use of DC vs AC traction motors. The class 1 RR's have found that DC technology still works good for fast freight where as AC technology is best used in the heavy/slower coal and manifest market.

AaronJ

The answer to your first question is cost versus advantages.
In high speed intermodal and medium speed general freight service
every major railroad except Canadian Pacific has come to the conclusion
that AC does not offer enough advantages to offset the higher purchase price. However in heavy duty bulk train service AC locomotives offer distinct advantages. When it comes to 6000 hp.
locomotives AC traction motors are required to maintain useable
adhesion (controll wheelslip) unless you want a locomotive with
more than six axles.

GE builds both a AC4400CW (w/ AC drive) and the Dash9-44CW without.
Note both locomotives can be rated at 4000 hp. if the customer desires.

The SD70M or I can easily be distingushed from the SD70MAC by its
lack of traction motor blower bulge (aka "laundry chute") on the left
, or conductor's side.

Yes far and away most locomotives have traction motors, except for the
extremely rare on this continent diesel-hydraulic types.

I have to disagree with two of my collleagues' statements. It is my understanding that the GE F prime mover will not meet the tier 2 emission requirements. I also don't believe the UP has given up on using its AC6000CWs in high speed intermodal service. Many of them are currently being used on coal trains, but this is because there is a shortage of AC units for these trains. And the locomotive availability, while improving, is not quite at the level the UP would like.

Don Park

First, UP has brought some of the AC60 fleet over to Colorado/Utah coal service to allow for service at the now GE leased Burnham shops in Denver. Just do a UP trace on the 7500s and you will find that only about 1/2 the fleet is working coal. I suspect that once the current 1/2 is complete, they will be rotated out and the other brought in if needed. As far as a shortage of other AC power for coal on the UP system, I find that hard to believe when I see numerous AC4400s pulling manifest loads on the Overland Route and other UP lines.

Second, a there are several distinguishing marks between the SD70MACs and SD70/75/I/Ms... First as mentioned is the blower housing on the left side of the hood, this is a leftover from the 50 and 60 series units. The 70/75/I/Ms do not have this chute looking housing rather a flat panel. More importantly and easier to spot from either side is that the SD70MACs are longer than the other versions. You will notice the length difference behind the rear cooling screens. There is an extra ~2 feet back there before it tapers.

Third, in respect to EPA tier requirements and which engines will meet or fail has been a topic of discussion on this board before. I have seen responses both ways that the FDL and HDL engines will both meet tier 2, but others say not. Who do we believe? Only GE truely knows.

Bryan

This is likely a stupid question, but here we go...

General Electric's C60AC and EMD's SD90MAC each produce 6,000 for six axles for a total of 1,000hp per axle. This is the same hp per axle rating as GE's older 8-40B model (4,000 hp & 4 axles). My understanding is that the 8-40B was a fairly successful design (reliability notwithstanding), and the high hp rating per axle was perfect for high speed intermodal service on SP and ATSF's flat desert transcon mainlines.

It seems that the primary advantage to AC traction motors is their low speed durability and tractive effort ratings, and therefore provide little or no benefit at high speed, such as on intermodal

So the question is, why don't the big 2 produce a 6,000 hp DC locomotive for high speed intermodal applications? Wouldn't this lower the acquisition cost substantially?

unit wrote:
>
> This is likely a stupid question, but here we go...
>
> General Electric's C60AC and EMD's SD90MAC each produce 6,000
> for six axles for a total of 1,000hp per axle. This is the same
> hp per axle rating as GE's older 8-40B model (4,000 hp & 4
> axles). My understanding is that the 8-40B was a fairly
> successful design (reliability notwithstanding), and the high
> hp rating per axle was perfect for high speed intermodal
> service on SP and ATSF's flat desert transcon mainlines.
>
> It seems that the primary advantage to AC traction motors is
> their low speed durability and tractive effort ratings, and
> therefore provide little or no benefit at high speed, such as
> on intermodal
>
> So the question is, why don't the big 2 produce a 6,000 hp DC
> locomotive for high speed intermodal applications? Wouldn't
> this lower the acquisition cost substantially?

I will take a wack at answering this. One of the claimed benefits of using the 6000 hp locomotives is to replace older 3000 hp locomotives on a two for one basis. To be able to start the load or pull up a hill, you not only need the horsepower, you also need the traction. However, you could build a 6 axle 6000 horsepower DC locomotive that would perform just as well at speed except for reliability (DC motors have brushes). You could also build 8 axle locomotives. EMD had an experimental locomotive running on Burlinton Northern about a decade ago that had a steerable 4 axle truck on the rear of the locomotive (probably a SD40) and the standard 3 axle truck on the front. Maybe someone can supply a picture of the locomotive.

On another subject brought up in this tread, I am not sure that the 2-stroke diesels have an inherent pollution problem. They certainly run cleaner than the current 4-stroke GE engines. They may have a very slight disadvantage on economy when compared to a 4-stroke engine as some of the supercharged (but clean) air ends up going up the stack.

Reference previous thread on Tier 1 & 2 emission info:

http://www.trainorders.com/discussion/read.php?f=1&i=92286&t=92223

All that I can add is that the GE 7HDL and EMD 265H were designed to meet not only Tier 1 but Tier 2 requirements. From what I understand the 7FDL can be made to meet Tier 2 as well, whether GE decides to market both engines once Tier 2 kicks in is another question. You must also remember that the two biggest obstacles to meeting Tier 2 are NOx emissions and Particulates. NOx emissions and Particulates can be controlled by changing the timing of fuel injection, but 2-stroke engines such as the 710 also allow a certain amount of the intake charge and lubricating oil to escape into the exhaust, resulting in particulate emissions. Given this, 4-stroke engines can be modified to meet Tier 2 without a huge amount of problem, but it will be near impossible for any 2-stroke engine to stop emitting Particulates out the exhaust.

AaronJ

I know someone will have more info on this, but here's what I know about the BN unit mentioned (and if need be, I can go look it up from the old Extra 2200's). It was an SD40P and they took two SD9 trucks, cut 1/3 off each and mounted them under the rear. The front truck was in an A1A configuration for a total of 6 powered axles. A few years later, Santa Fe had a 4 axle unit (I think a GP50) with a 2 axle radial truck. Shortly after that, the SD70's emerged. I also think EMD sd60 #3 had the radial trucks installed, most likely before the first SD70's were built.

How are the GE steerable trucks performing? It seems like the EMD radials are really good. I'm curious about the tolerance allowed per each wheel though, only 1/8" between all 6 wheels for the EMD's...seems a bit tight, but I'm just asking.

mcdeo wrote:
>
> It was an SD40P

Actually, it was SDP45 6599. There have been a couple of threads
with photos and descriptions of this unit - see this thread for one:

<A HREF="http://www.trainorders.com/discussion/read.php?f=1&amp;i=74847&amp;t=74847&quot;&gt;http://www.trainorders.com/discussion/read.php?f=1&amp;i=74847&amp;t=74847&lt;/A&gt;

About the 6000hp DC drive units, the 1000hp-per-axle 4-axle
units weren't really "ideal," as evidenced by ATSF and SP
ultimately going back to 6-axle power. I've heard varying
reports, but apparently the wheelslip technology on high-horse
4-axle power is good enough to hold dry rail, but on wet or
greasy (i.e. flange greaser) rail, they tend to let go, or
the wheelslip control derates them into uselessness even at
relatively high speeds. Somebody mentioned that with AC you can
achieve a higher factor of adhesion, which is probably one of
the reasons it was used on the 6000hp beasts rather than DC.

Another question is do railroads really want to buy highly
specialized locomotives that will be inflexible, or at least
underutilized, in other applications? We've gone from steam,
purpose built for specific applications, to the general purpose
diesel that could be plugged in anywhere, back to locomotives
that are almost purpose-built for certain types of tasks or
trains. I'm really curious to see if the Green Goat takes off
on the Class 1's, if the economies of fuel savings, purchase price,
maintenance, etc. will be enough to offset the inflexibility, the
fact that these things can *only* be used as yard switchers.
Railroads apparently weren't hesitant about purchasing 4000hp
AC-drive units that are ideal for lugging coal and grain below the
minimum continuous speed of DC drive units. UP was the road
that spurred the development of 6000hp locomotives, and I suspect
their interest in further development, AC or DC, has probably cooled
for a while.

Again it is the application. As I look at consists nationwide, I do notice that there is a bit of standardization, and yet specialization.

An example or two.

Most all units built on the UP have been equipped from the factory with UP CSS, and CNW ATC. Many units like the 8500's may not see the territory that uses these signal devices, yet if needed, they are ready. Many of the former UP SD40-2's do not have ATC, so their usage is limited in this part of the woods, at least as leaders. You get the general idea.

The AC60's are equipped for just about any application needed, however are prefered on heavy coal and grain. In a recent survey I did on the assignments of the 8500's and 7500's, I noticed that there was a definite difference.

None of the 8500's were assigned to bulk trains. 28 of the 8500's were at or going to VMV or at the shop in NLR. 8500 - 8519 were in the Roseville area, while 8520 - 8561 were in the Texas / NLR /Memphis area.

Eight of the 80 7500's were in or heading to the Denver shop. Nine were assigned to other than bulk trains. One, the 7512 was in Intermodal service. One set was assigned to a tank train in Deloras, California. The rest were in grain and coal service system wide.

UP is so big, that they are able to assign a group of units to a particular service, without loss of fleet utilization. In Iowa, there are two dedicated groups of units for grain service. One is the cycle power used for trains going to and coming from Iowa Processors (ADM, Cargill, &t.). Another is "shuffle power" assigned to the Iowa grain lines. This power is used at terminals to move grain from the elevators to terminal so when road power arrives, the train can depart without delay. Last year the power, all four axle types, was comprised of B23-7's/30's. This year GP60's have been assigned to Eagele Grove, Des Moines, Mason City, and Council Bluffs in that service. They may also be seen on locals or in plow service as needed on the branch lines. The lines in this area last year would have suffered a lot more delays if it were not for the availability of these shuffle units for plow service.


My two cents,

RRKen
Mason City, IA

RRKen wrote:
> The AC60's are equipped for just about any application needed,
> however are prefered on heavy coal and grain.

That is only a relatively recent occurance though. When the C60ACs first started coming on-line they were being used for stack trains. They were not used for coal and rarely seen on other types of unit trains. Something changed a few months ago and the C60ACs were removed from stack trains and moved west for coal. I wonder if there are now enough SD70Ms on-line that it freed up the C60ACs to be used elsewhere. It seems like the UP prefers 4000/4400HP DC locomotives for everything but coal.

Kevin Kuehl
kevin@ktlx.net
http://ktlx.net