I just read that CP, like UP some time ago, will remove their four SD90MAC’s from active service. Does anyone know why seemingly the experiment with 6000 HP is over? What about the future of the four cycle 265H?
The SD90MACs (and GE’s AC6000CWs for that matter) have proven to be unreliable and rough-riding, which is why many of them are being withdrawn from service. Some SD90s and AC6000s were designated SD90/43MACs and AC6000CW Convertibles and were given less powerful, more reliable prime movers (approx. 4300hp for the EMD, 4400hp for the GE) when built. The manufacturers gave the railroads an option to upgrade to the 6000hp powerplants at a later date. The SD90/43s and AC6000 Convertibles with the less-powerful prime movers may be less of a target for withdrawl. Most railroads have settled on 4400hp as the upper limit for horsepower ratings as it gives the best amount of operational flexibility.
As for the H-engine, China is considering buying about 300 locos form EMD with the H-engine as their prime mover.
Easy to many TEETHING problems and the fact that it is an ODDBALL engine like a CAT engine would be in the fleet. Think about it they only have 4 of them TOTAL and parts supply could be hard.
The problem with the H engine is production was VERY rushed. EMD had been fooling around with a smaller bore 4 stroke, but when the demand for a 6000 HP AC locomotive appeared, they basically scaled up their 4 stroke design and the H was born and placed in production. Given that unforeseen problems creep up every time even a minor change is made on a proven design (EMD F engine, anyone?) that the H engine was headed for trouble shouldn’t have been a shock.
The shock was that UP purchased so many of them right off the bat.
It’s also why Conrail purchased their AC units with 20-710Gs (not saying that CR was smarter than UP. Draw your own conclusion [;)] )
Now im realy confused. So the engine in a 90mac is a 4 stroke then?
Whats in a 43/90mac? Is this a 2 stroke 16 cylinder 710G??
Im presuming here, the 90mac was the 4 stroke but later downrated to the 2 stroke 710 to 4300hp, correct?
SD90MAC is a four stroke. well it was for the time being.
and you are correct on the 43/90 having the 710g 2 stroke
and you are right on the third question?
EMD’s rush to put the 265H into production appears to be quite similar to what Alco did with the 244. Unlike Alco, EMD had a fallback position with the existing 710 design.
As another forum member said (Can’t remember who), the SD90MAC was like the SD45 of it’s generation.
Thanks for clearing that up[8D]
While this might be true for the 90MAC, not so much for the GE’s. CSX seems to like the ones they own, and are still top shelf power.
I think the SD45 was a pretty good locomotive. It had some early problems. They were solved.
RWM
The SD90MAC was constructed as a 6,000 hp locomotive equippped with a 245H. The SD9043MAC was constructed as a 4,300 hp locomotive equipped with a 710G, with potential to install a 245H at any subsequent date – the electrical, cooling, and auxiliary systems were constructed to handle 6,000 hp. I don’t know if any SD90MACs were ever re-equipped with a 710G. Maybe a few were, but I don’t recall hearing about it.
RWM
Is the ‘rough-ride’ quality related to additional weight?
I thought it was the SD80MAC that was compaired to the SD45, as both locomotives have 20-cyl prime movers.
As far as I know, the four CP SD90macs are all still in service,as well as the fleet of SD9043macs…they tend to stay in Canada because that’s where the repair base is…St.Paul,Mn handles all the GE’s,so we see AC’s and ES’s almost exclusively…
Don’t get me wrong, I love any 45 series. Yes, EMD solved the issue of the crank shaft, but the 45 series was less realiable when not kept in proper maintence. Other regionals did very good with the SD45 though, WC, MRL, NYSQ, ect.
Figuratively speaking, the SD45 was the biggest most powerful locomotive in its day. It was pretty big for its size, so was the SD90MAC, but in the 3rd generation of locomotives.
Alright let’s stop with the SD45 thing, this is a 90MAC thread, so PM if you would like to discuss more. [:)]
So, where does all this leave the 265H engine? Being developed for Chinese co-production? Marketed to marine applications? Chatter is that 4-stroke is better suited to Tier 2 and later emission requirements, so one might think that EMD would be emphasizing whatever R&D money they have on this. But the ever-reliable 2-stroke 710 seems to get the attention.
Speaking of 90MACs, now that they are gone (mostly), did anyone record them while running? I tried several times but never got a difinative sound recording of the engines working hard. What did they sound like - GEs, Alcos, none of the above?
Marv Van De Weert
We use to get one every now and then at the Weston Power Plant. i I never caught it running. I’m not sure if any I caught in Rochelle where 90MACs, and not 9043MACs. But I did catch a few working as helpers at Moffet Tunnel. I’d have to watch ti again but they sounded like an EMD. lol.
The SD90macs (6000hp) sound a lot like a GE…the 9043macs sound like a “regular” EMD with the 710 engine…