A little Q about those EMD "Centennial" locos...

June '05 issue of TRAINS has a photo and short article on the movement of some remaining EMD Centennial locos and they’ve been mentioned in another post here on the Forum about a TV show up over. What caused their demise? Did the axle loadings prove to be too much for many lines? Their fuel consumption too high? Or just too much power tied up in one loco that proved to be too inflexible compared to a lash-up of smaller hp locos…?

Dave [:)]

6,000 eggs all in one basket has been cited in one article that I read. Although there were two prime movers, if one needed to be serviced, the whole locomotive, all 6,000 horses, were in the shop for the duration of the repair.

…I wonder if they could work with only one prime mover in operation hence saving fuel if total power was not needed. They were big brutes. I’m betting on too much power tied up in one package.
Dave: are you just getting back from Holiday…You have been away from here for some time now…

Hi Quentin - yes, I had a great time catching up with old friends down south in Sydney and a very close friend in Merimbula (pronounced Mer RIM bu lah) (far south coast of New South Wales) whom I hadn’t caught up with in quite some time. Very relaxing, not much running around, which is what I needed…

Dave

If I remember correctly, the AC6000CW and SD90MAC did not sell well because railroads decided they had too much power in one locomotive.

Maintenance headaches, and, as Kozzie pointed out, not a very flexible locomotive, with limited use.
Ended up the same as the Big Boy, with the variable usability of the newer locomotives, the need for it disappeared.
Still an impressive machine.

Ed

…Sounds like a really great time off from the routine Dave.
Remember as we communicated while still in Spring time for us I was telling you we were in the 90’s already…Guess what…We’re still in the 90’s…It’s been a hot one here for our area and humid. But it’s Summer and I like it…

I guess EMD must have done research into the possible market for these giants before production - but maybe they overestimated the usefulness of a huge single unit.
Ed has mentioned maintenance headaches, which would no doubt run up costs.
At the risk of asking a Q that perhaps should be on the MR forum, have they ever been produced in, e.g., HO scale?

Dave

Wow Quentin, you are getting hot weather! As long as the humidity isn’t too high…

Dave

I think Overland did one in brass…which cost a lot of “brass”…
Dont know if a less expensive plastic one was porduced…

Oh, and down in the swamp, it started out at 85 degrees @6:00am, hit 98 by 1:00pm, and thunderstorms by 5:00pm, its cooled down to a mild 88 at 10:46pm…

If you dont like the weather in Houston, just wait a minute…

Ed

Thanks Ed - sounds like your temps are like some of the Summer days here in Brisbane…

Dave

They were just 2 GP40-2s on a single frame.

As far as maintenance, no more required than the standard GP40-2, however taking one out of service was like taking two 3000 hp units out.

They were sucessful–most racked up 2 million+ miles before being taken out of service.

Athearn makes them in plastic HO at a nice price.

They certainly had the future there with a wide cab and 6000hp!

Dan - a good point - UP sure used the big stuff.
GP40-2’s point was also interesting, about the wide cab as well as the big hp

Dave

The July 1991 issue of CTC Board has a 18 page article about UP’s GE, ALCo and EMD double-diesels written by Mark Hemphill.One problem the DDA40X had was the high speed gearing of 59:18(90 MPH) instead of 62:15 (70 MPH). 75 SD40-2’s were given the same gearing.This made them ill suited for slower trains.

From page 42;
Less obvious were there unique internal specifications, and this was where the big problems lay. Their prime mover, a 16-645E3A, was peculiar to the species, with its own power assemblies, turbocharger, fuel injectors, and so forth.The AR12 main generator was likewise an oversize oddball-every other EMD dash 2 ever built has an AR10. Their modular electrical cabinet, that paragon of EMD standardization ? Its modules for the most part were special, or shared with the SD45X, the real freak of the locomotive world.
To put it bluntly, the Jacks needed their own parts inventory, and their idiosyncrasies made them more vexing, expensive to operate, and time-consuming to repair than twice their number of SD40-2s.

They had 6600 HP.

The model situation is a little complex - Athearn made a DD35 rather than the “Centennial” DD40AX. Bachmann offer the full DD40AX as UP bought though I’m not sure what the model is like. I can say that the single-motor Athearn isn’t worth bothering with as standard - there’s not enough “grunt” in it to cope with the weight of the loco and the extra-long driveshaft at one end is a pain. Mine will probably recieve a new motor or motors at some point. There were also B-unit versions that looked much the same but minus the cab (similar to the GP9B).

The higher speed gearing wasn’t put on the Centennials until later in thier life. Then they were dedicated to intermodals and pooled with the “Fast 40s” which were SD40-2 with identical gearing. Earlier the Centnnials had standard gearing and were used in the general pool on the UP’s main line.

What really brought the downfall of the Centennials was that they were worn out. They had multiple millions of miles on them when they were retired.

I have a 1985 edition of Video Rails 30 minute video “Union Pacific Centennials.” I have enjoyed it for years. I see that Pentrex offers a 1994 edition, which I think is the same as the 1985 edition, for $9.95 at there web site. Here is the link: http://www.pentrex.com/vr006.html

Jim

The Centenials were also used on the high speed Livestock Specials. UP generally put a lot of horsepower on their faster trains to get them over the road, sometimes 8-10 GPs on the western divisions in the early days. They tried GP B-units, then the DD35 B’s and later the Centenials. When used in Intermodal service 2 Centenials and a Fast 40 was a common configuration. That’s 15,000 horespower, not all that much more than double-headed Challengers common on the faster trains during the steam era.