4-axle comeback

[MLG4812]

    Am I the only one that reasons as to why many of  the class 1's do not utilize more 4-axle locomotives? I went to the Port of Long Beach site and was analyzing the projections of future growth in intermodal. Of course, it described the TTT (triple-track trench) and its growth in traffic and increase of capacity. My concern is:

 

1.) If intermodal is increasing (and it is), why not use more 4-axle to power these trains. Container trains generally aren't as heavy as other freight and are tailor made for lighter locomotives. Many class 1's would suffer a HUGE loss without this traffic but yet these trains are still being headed by multiple, big six axle -9's, MAC's, "Special Deliveries", GE"no's", ect. I understand that 4-axle units have a rather limited hp-TE ratio. 4000hp is about the limit I believe. However, most of these big 6's don't utilize all of their hp or traction effort even on the big grades with lighter intermodal trains.

 

2.) The "Green" movement. How much fuel would multiple six-axle consists consume compared to a four-axle lash-up on your longer land-bridge intermodal runs? Quite a bit I'm sure.

 

Now I'm not saying replace everything with geeps, but it would seem that some RR's would fair far better economically by "mixing it up" a bit in the power department.

 

MLG4'8.5"

 

[CSSHEGEWISCH]

Neither of the major builders even offers 4-motor power.  The three lesser builders (NRE, MPI and Railpower) offer 4-motor locomotives, but they are specialized for yard or suburban service.

[CNW 6000]

Well what about rebuilding some B40-8s or something like that?  Could you make one of those into a 4 axle GEVO or something?

[coborn35]

The thing is, at this point in life, most of the railroads GP's are getting pretty beat up. BNSF did redo alot of its GP38-2's recently, but still.

[timz]

"most of these big 6's don't utilize all of their hp or traction effort even on the big grades with lighter intermodal trains."

And the four-axles would? Because they'd have less total horsepower? You're saying trains today are overpowered?

[Colorado Railroads]

I remember reading somewhere that six-axle units are more suited to powering large tonnage loads while four-axle units are better for quick acceleration with lighter loads. If you're one of the big four, you'll be looking for the former to haul the big loads over the big hills and long distances. It doesn't matter if you're getting X horsepower when your wheels can't gain traction on the rails like a six- (or eight- ) axle unit.

Given that the current commuter rail needs are filled by a lot of electrics and F40PH's, we probably won't see any R&D or offerings from EMD or GE any time soon.

[chad thomas]

- Wide cabs are too heavy for 2 axle trucks, and most new road locos are wide cabs.

- Modern road units are to powerfull for 4 traction motors to handle.

- Steerable 6 axle trucks can handle what use to be 4-axle only territory.

 

[diningcar]

Not yet mentioned but significant: Diversity!!!

The major long haul RR's want to be able to use their power whenever and wherever there is a need. If a solid grain filled hopper train arrives at LA the power may be used on a intermodal train, probably with fewer units than were on the grain train. Many other examples could be mentioned but it seems obvious that diversity is a major criteria when purchasing power.

[Colorado Railroads]

Not yet mentioned but significant: Diversity!!!

The major long haul RR's want to be able to use their power whenever and wherever there is a need. If a solid grain filled hopper train arrives at LA the power may be used on a intermodal train, probably with fewer units than were on the grain train. Many other examples could be mentioned but it seems obvious that diversity is a major criteria when purchasing power.

I'm not sure I understand this reasoning. My limited experience tells me that the more models and makes you add to your fleet, the more expensive it gets to maintain it. Diversity seems less economical. 

[CNW 6000]

- Wide cabs are too heavy for 2 axle trucks, and most new road locos are wide cabs.

Um what about CN's GP40-2Ws?  They are wide cabs.

[arbfbe]

Who thinks intermodals are short, light, fast trains anymore?  They are now 8K tons and 8K feet long moving at the speed of the rest of the traffic.  So why should the power be any different?

Four thousand horsepower on 4 axles is a slippery combination on mountain grades and in the rain, 6 axle wheel slip is easier to control.  Given the smoke opacity restrictions in the CA area new units will quickly be banned from service there and it make sense to purchase power which can be moved to coal and grain service in other parts of the country in a few years.

The era of the 4 axle mainline road unit is over.  The UP figured that out after the experiment with the GP40X units.  Building the roster around high horsepower 6 axle units adds to the flexibility of the railroad better than any other option.   

[MLG4812]

"most of these big 6's don't utilize all of their hp or traction effort even on the big grades with lighter intermodal trains."

And the four-axles would? Because they'd have less total horsepower? You're saying trains today are overpowered?

 

To be honest, I'm really not at liberty to say because I don't know the total tonnage of most intermodal traffic. However, many of your 6'ers can output well over 100k of TE. A couple of these are more than enough for your average stacker. But since intermodal by its nature is an industry based on timely service, speed is the factor for overloading many of these trains. Yes. I understand that trains face some pretty big grades coming out of CA, WA, ect., but what about the grasslands? What about the run into Chicago? I believe at least trains could be repowered in say Deming, NM or El Paso with four axle. One poster did state that many of today's stacks are 8000ft and beyond at 8K tons....really? Wow? In that case, of course six-axle would be more logical.

 

MLG4'8.5"

 

[samfp1943]

Not yet mentioned but significant: Diversity!!!

The major long haul RR's want to be able to use their power whenever and wherever there is a need. If a solid grain filled hopper train arrives at LA the power may be used on a intermodal train, probably with fewer units than were on the grain train. Many other examples could be mentioned but it seems obvious that diversity is a major criteria when purchasing power.

I'm not sure I understand this reasoning. My limited experience tells me that the more models and makes you add to your fleet, the more expensive it gets to maintain it. Diversity seems less economical. 

http://www.trains.com/trccs/forums/1045844/ShowPost.aspx

Here is a link to a TRAINS Forum on using old C+C's to rebuild as BB+BB loco's in Brazil--Now there's a way to create diesel diversity!

[Murphy Siding]

Not yet mentioned but significant: Diversity!!!

The major long haul RR's want to be able to use their power whenever and wherever there is a need. If a solid grain filled hopper train arrives at LA the power may be used on a intermodal train, probably with fewer units than were on the grain train. Many other examples could be mentioned but it seems obvious that diversity is a major criteria when purchasing power.

I'm not sure I understand this reasoning. My limited experience tells me that the more models and makes you add to your fleet, the more expensive it gets to maintain it. Diversity seems less economical. 

I'd have to believe he meant flexibility, not diversity?

[chad thomas]

- Wide cabs are too heavy for 2 axle trucks, and most new road locos are wide cabs.

Um what about CN's GP40-2Ws?  They are wide cabs.

I am not sure about the GP40-2Ws, but SF had problems with the B40-8Ws and GP60Ms (the last 4 axle wide cab road units built. Perhaps the 40s were built without the collision post.

[CNW 6000]

I dunno.  Randy?  S. Hadid?  Ed?  Anyone?  Bueller?

[BaltACD]

Class I's only use for 4 axle engines is where the trackage will not support 6 axle engines.....yard, industry and low grade branch line uses.  The manufacturers lack of 4 axle offerings mimics the path the industry is taking.

[Lyon_Wonder]

Well, 4-axle locos are still good for yard work and local freight hauls. Here in Illinois, I still see BNSF using GP30/35/38/39-2s and other various 4 axle rebuilds hauling tank cars and various freight to and from a local plant.  Maybe at some point the railroads will be adapting more Gensets and 4 axle rebuilds that use prime movers that are envirnmentally friendlier, especially when Tier III and  stricter emissions laws in California come into effect.  I here some railroads are toying with rebuilds using Tier-II compliant Cat engines, and a rumor has it that EMD may offer a 710G upgrade kit for 645-powered locos, something which I thought wasn't possible without a rebuild.

http://www.trainorders.com/discussion/read.php?1,1456644 

[WCfan]

Well, (I don't know if this is helpful or Not) but CN still uses 4-axel units. I know all of the former WC GP38-2s are in BC. It has something to do with the DB, I really don't know what. I also see from time to time (on our subdivision) a former WC GP40 on 2 SD40-2 consist. (Some times there is a SD40-3 in place of the SD40-2s) I also saw in the yard today, a CN GP40-2LW on the NB. I mainly see the WC GP40s at Stevens Point doing yard work. So really, they still have a use.

[Gluefinger]

To be honest, I'm really not at liberty to say because I don't know the total tonnage of most intermodal traffic. However, many of your 6'ers can output well over 100k of TE. A couple of these are more than enough for your average stacker. But since intermodal by its nature is an industry based on timely service, speed is the factor for overloading many of these trains. Yes. I understand that trains face some pretty big grades coming out of CA, WA, ect., but what about the grasslands? What about the run into Chicago? I believe at least trains could be repowered in say Deming, NM or El Paso with four axle.

Yes, but in the essence of speed, why spend the extra 20 minutes shuffling power around? 

Crew changes on these trains can be accomplished in five minutes. 

[GP40]

You can tell from my moniker I LOVE high HP B-B power.

The GP40-2 was the symbol of revitlalized northeast railroading when Conrail purchased a bunch of the 3300's for high speed TrailVan service with 61:16 gearing (77 MPH max speed). The same spec's as their ex New York Central GP40 brethern. Being a New York City railfan the GP40 with the exception of the U33B was the most powerful mainline diesel power to actually enter the city limits of New York. From the NYC to PC to Conrail eras you see them idling at the 72nd St.(or as some call the the 60th St.) Yard btween run to Selkirk Yard right near the heart of midtown Manhattan.

After that long ode to the GP40. High HP B-B's like that are not coming back as mainline roadfreight power. Just as Southwest Airline flys only the Boeing 737 to keep cost down, RR's are buying HP C-C's for essentially the same reason bacause the cost of a typical new built road unit has gone from being a couple hundred thousand dollars a unit to a couple of million dollars a unit. So the same unit has to be a jack of all trades regarding train assignments. And just the 737 has increased in performance so it now to the job of its larger brethern like the 727 and 757. So as high HP C-C power increased in performance to do the job of smaller High HP B-B brethern.  

In the past a 3000 hp B-B(i.e. GP40's, B30-7's) would put out 750 HP per axle(not to mention the slippery U36B with its 900 HP per axle). Now we have 4400 HP C-C's (i.e. the SD70e and E44DC's)putting out their 733 HP per axle with a greatly more efficient transmission, meaning more of that 733 HP per axle is getting to the rails more that the old 750 per axle units would (even with DC traction motors) and ton more superior wheel slip control technology. All this out of a 12 cylinder prime mover as opposed to 16 cylinders and is over 20% more fuel efficient and meets the EPA Tier III standards.

Aother operational problem the High HP B-B's like the GP60M's even the regular GP60's had was a high weight on axle loading meaning that they had to restrict the size of the fuel tanks to keep thier down and be careful on what bridge structures they ran across.  The nee Central of New Jersey RR's GP40P's have massive fuel tanks and weigh nearly 300,000 LBS and to this day Amtrak forbids NJ Transit to run these units on the NEC because of the weight on axle issues. They had no problems in the Conrail era with modern C-C's like the SD60's and C40-8's as long they had cab signalling. Because their weight was spread over six axles not just four.  

So as the previous posters said B-B power inow is for specialized duty like yard goats and passenger service like the P42's and MP36's.    

[SD60M]

"most of these big 6's don't utilize all of their hp or traction effort even on the big grades with lighter intermodal trains."

And the four-axles would? Because they'd have less total horsepower? You're saying trains today are overpowered?

In a way yes. About 3 months ago i was going to school and was stopped by an intermodal train it had 3 UP SD70M's an and only 20 cars?!?? Thats a strange site to see i bet a single GP38 could handle that train with no problem!

[Colorado Railroads]

- Wide cabs are too heavy for 2 axle trucks, and most new road locos are wide cabs.

Um what about CN's GP40-2Ws?  They are wide cabs.

So are BNSF's GP60M's.

 

[tree68]

I'd have to believe he meant flexibility, not diversity?

I'd agree.  Having a limited number of types of locomotives is going to be a hit with the maintenance people. 

I believe there is a trend toward longer trains - hence the reasoning that a couple of six axles is a good use of resources.

As I recall, the GP40 - 3000HP on four axles, was a fast runner, but was also said to be slippery.  And a fast locomotive is of little use if the rest of the traffic is running more slowly.

[silicon212]

SP/UP GP60s were/are rated at 277,000 lbs, same as a GP40-2.

[ericsp]

SP/UP GP60s were/are rated at 277,000 lbs, same as a GP40-2.

The SP roster I have (August 1990) lists the SP, SSW, & DRGW GP60s as weighing 287,000 pounds.

[1stFalcon]

The GP 50 would ride pretty rough on the C&NW compared to the SDs when pulling a Falcon. Six axles always makes for a much nicer ride. And the C&NW did not buy any more four axle road units while I was still there.

[Anonymous]

Crews would throw a fit if you made them sit in a old broken down no air conditioned hunk of junk like a GP38 for half a day.

Ever seen what you have to do to get into the toilet of one of those things?

Plenty of GPs still on locals and in yards.

More axles win!

[silicon212]

SP/UP GP60s were/are rated at 277,000 lbs, same as a GP40-2.

The SP roster I have (August 1990) lists the SP, SSW, & DRGW GP60s as weighing 287,000 pounds.

You're right, and when I got to thinking about it, the 277k number is what I remember stenciled onto the back of the cab on a GP40-2 - on the electrical cabinet door.

[carnej1]

- Wide cabs are too heavy for 2 axle trucks, and most new road locos are wide cabs.

Um what about CN's GP40-2Ws?  They are wide cabs.

So are BNSF's GP60M's.

 I have read quotes from ATSF/BNSF engineers stating that the GP60M's were disliked due to the fact that the greater weight of the widecab on the front 2 axle truck led to rough riding issues...