Any one know why EMD stopped production of this unit?
The railroads were unsure of the 20V-710G and the SD90AMC had been announced. Why go for 5000 horsepower when you could have 6000 horsepower.
I’m not so sure that the SD90s are any more popular.
A railroader friend indicated that the railroads are loathe to invest in the big beasts, as compared to smaller units which provide more flexibility of deployment.
e.g. if you assign 2 of these 90’s to a heavy train and one goes “down”, out on the road – will the remaining single unit have enough power to bring the train home ?
Comparatively, if you were using three SD70s (and one went down) the remaining 2 units would have a better chance.
There were two additional orders for the SD80MAC from CONRAIL and Canadian Pacific but both were switched to different models before production began. CP decided it wanted "convertible"SD90/43MAC’s(plus what turned out to be a small number of SD90MAC-H’s with the 6k hp HDL engines),apparently they were impressed with the UP program at the time(but since then none of their SD90’s have been converted with the HDL). CONRAIL,apparently satisfied with the performance of their small SD80MAC fleet wanted another 30 of the beasts,but it’s merger partners CSX and NS did not, so the order was split between SD70MACs for CSX and “spartan cab” SD70’s for NS. The latter were all assembled from EMD supplied kits at CONRAIL’s Juniata shops, and were delivered in CR colors.
Having both orders for the model changed must have led EMD to conclude that further marketing and development of the model was futile so it was dropped from the catalog. I had the pleasure of watching and photographing the “Big MACs” in service on the Boston line,quite an impressive sight(as are the AC6000CW’s that replaced them when CSX took over)
Where they successfull in that were they well received by crews and mantenance guys and did they do as advertised?
Thanks for all the replys.
carnej1 [:)]
stantaras [:)]
Welcome, both of you, to the forums. [;)] I know you will enjoy them.
Using this logic why would you not buy a large number of new lower-horse power units and then you could have four 2000 hp units instead of two 4000 hp units. The thing is the newer high horse power units are much more reliable than before. I have heard though that the SD90 's have had a number of problems. This mutes my point so I am going to shut up.
One reason, and there might be others, is the fact that two engines will burn less fuel than four engines. This of course saves the railroads money. Funny thing, railroads like saving money. They can get carried away saving money as is the case in the remote control engines.
I heard that the SD90MAC unit availability record was not good, somewhere around 80%. Why spend good money for something that will be in the shops a fifth of the time? The SD70M, on the other hand, has an outstanding availability record, though I don’t recall what it is. Power constantly costs lease money whether running or not. Thus, the deciding factor on the SD80 may have been its availability record.
Without a definitive statement from CSX or NS or EMD, we’re never really going to know the exact reasons why the decisions were made. I’m not going to worry about this, because (a) it’s unlikely they’ll ever let anyone that deeply into their internal decision-making, (b) even if they do tell you, it’s difficult to gauge if what they’re saying is spun or not, and (c) decisions like this are so complicated and drawn out and involve so many people that the players may not even know exactly what they did, why they did it, and when they did it. So even if you had a tape recording of every conversation ever made on this subject, you’d probably not be able to figure it out. Railroading is an inexact science. When you delve deeply into these decisions you end up measuring intent. Even the Supreme Court doesn’t try to measure intent; they presume it, based on reasonable behavior and known outcomes.
Which locomotive model to purchase is an outcome of considerations of price, performance, and need. Any one of those three criteria being seriously out of whack compared to other choices means the model is unlikely to be purchased. Secondary factors include time of delivery, value in a secondary market, and opportunity cost.
Price: All other things being equal, a locomotive with a 20-cylinder engine is going to be more expensive than a locomotive with a 16-cylinder engine. Do you get value? Only if you get a better match between performance and need. How much better a match? That’s a very tricky thing to calculate.
Performance: You only get to take advantage of more horsepower at higher speeds. At 3 mph, you can’t tell the difference between an SD70MAC, SD80MAC, or SD90MAC. At 50 mph, the big-horsepower locomotive will make itself known. Can you realize these speeds often enough? Enough to make a difference in crew costs, track time, lower car-hire, happier customers, more market share, fuel burn, maintenance, revenue, profits? Can you even measure these accurately? I rea
becouse once word got out to the other rail roads from the conrail crews that they are nothing more then over priced junk…the other rail roads did the smart thing…BOUGHT GE’S
hahahahahah
csx engineer
Well at least we now know why CSX is having so many problems – they bought GEs. [;)]
Mr. Harrier’s post arrived while I was typing. He’s right; availability is a very important factor. Our sources tell us SD70M availability at UP is in the 94-96% range.
Take a calculator. Say you can choose between 1000 6000-hp, 80% available locos at $2.5M each, and 1000 4000-hp, 95% available locos at $1.5m each:
1000 x 80% x 6000 = 4.8 million horsepower available every day
1000 x 95% x 4000 = 3.8 million horsepower available every day
If the price per actual available horsepower was proportional, you would get:
1.5B/3.8M = x/4.8M
7.2 = 3.8X
x = 1.89B
That is, the 6000-hp loco is worth only an extra $390,000/unit. Unfortunately, they cost you an extra $1,000,000/unit. That’s going to be a tough sell to your boss!
Granted, this does not figure cost of maintenance, fuel, etc., etc., but you can see what an enormous cost hole the 6000-hp loco already has to dig out of.
A rule of thumb is the fewer units you have the better. The reason we know that is that that “thumb” keeps getting hit with the hammer of reality so often we can see it extending out from underneath that reality.
What Mr. Hemphill is saying is correct. However, I would like to make one statement in response. And that is fuel consumption. There is only so much energy in a gallon of fuel. An SD9, for instance, burns the same amount of fuel per ton per mile for a given throttle setting (Run Number) as an SD-40 or an SD-45 (the original 20-645 engine), or a GP 35, or a GP 30. Factoring out the newer locomotives increased fuel efficiency, a SD 90 burns the same fuel per horse per mile for a given run #.
The point here is, fuel use is not a “show stopper” issue.
Second comment: New power, regardless of horseposer or transmission type, will only be purchased under one of the following reasons (or a combination of them);
A) You simply can’t keep the old engines running anymore.
B) A law (such as emissions rules).
C) The purchase the new unit will cause a total outlay less than not purchasing it.
D) You can keep the engine running (see A above) but repair cost and availability are unacceptable (see ALCO and Baldwin).
E) The &$(#)%^(^&%$^##@) locomotive causes excessive track damage (see ALCO and Baldwin) where others (see EMD) don’t.
A, D and E were major reasons for the early demise of several locomotive builders diesel offerings. Baldwin, for example, built 3,000 HP and 6,000 HP Centepedes in 1943. Built only one 6,000 HP unit ((4-8-8-4 750/8 DE) with 8 diesel motors and a 2D+D2 wheel arrangement. 64 3,000HP units were built (DR12-8-3000) with 4 diesel motors (same type in each HP configuration, 750 HP 408 model V8’s) with the last built in June of 1948. This when the FT and F3 1350 HP modles by EMD was selling briskly.
Do you see the pattern? It is value returned for dollars spent. Tha
There’s been a significant increase in fuel efficiency in the last 50 years:
Fuel consumption at notch 8:
SD9: 108 gal/hr, or 16.2 hp/gal/hr
SD40-2: 164 gal/hr, or 18.2 hp/gal/hr
SD70MAC: 192 gal/hr, or 20.8 hp/gal/hr
In other words, for one gallon of fuel, the SD70MAC does 28% more work than the SD9.
Imagine that over the 15-year lifetime of a locomotive, it works in notch 8 two hours a day and is shut off the rest of the time – a simple approximation of what it does. The fuel burned and work performed is:
SD9: 1,182,870 gal for 19,162,500 hp-hours
SD40-2: 1,804,945 gal for 32,850,000 hp-hours
SD70MAC: 2,105,769 gal for 43,800,000 hp-hours
We can get the SD9 and SD40-2 to perform the same amount of work by working them a few extra minutes every day, but there’s a fuel penalty. Assume that diesel fuel for the 15 year period is $1/gal:
For the SD9 to generate 43,800,000 hp-hours it will burn 2,703,703 gal
For the SD40-2 to generate 43,800,000 hp-hours it will burn 2,406,593 gal
SD9 extra fuel burn 597,934 gal, extra cost $597,934
SD40-2 extra fuel burn 300,824 gal, extra cost $300,824
If you run your locomotives 30 years, which is not unreasonable, the fuel savings of the SD70MAC over the SD40-2 pays about half of the SD70MACs initial cost.
Consider maintenance – either the SD9 and SD40-2 has to work more hours to do the same work, or you need more SD9s and SD40-2s. If parts cost the same and wear out at the same rate, the SD9 will cost you 28% more, and the SD40-2 14% more.
I hadn’t run these numbers before, and admittedly they’re crude approximations, but I’m beginning to understand why, even though an SD40-2 is still a good locomotive, UP has acquired over 1000 SD70Ms.
Mr. Hemphill
When one uses ball-park statements, one can get into doo-doo. Mudchicken spiked me to one of his ties with my ball-park statements about equilateral switches. I should have been remembering, but I was not.
For the -2 modles and the 710’s, you are correct. I was not clear, I was refering to SD40-1 and SD45-1. The figures we were given to work with on the SP were the same per horse per run number. -2’s were different since they had a new fuel use technology based on computer control rather than mechanical control.
One has to compare apples with apples, which I tried to do even though you needed to immagine some of the apples (the -2s and 710s). When EMD engineered the -2s and 710s, they improved on fuel use - almost 50% better in a 70 then a 9. One would have to imagine a SD70 with 567C technology to get “proper apples”, so I should have specified SD40-1 and SD45-1 which had, nearly so, the same fuel use technology as a SD9.
Eric: Just call me Mark. That “Mr.” bit makes me feel older than I already am 
Here’s the numbers for hp/gal/hr that I have that might be of use for SP (or D&RGW for that matter):
SD7: 16.1
SD9: 16.2
GP30: 18.0
GP35: 17.4
SD40: 17.9
SD45: 18.6
SD40-2: 18.2
SD50: 19.1
SD60 20.6
SD70: 20.8
Note with some exception (the GP35, not surprisingly), these show steady improvement.
This also shows that the conventional wisdom about the SD45 being a “fuel hog” is dead wrong. It is a little more thirsty at idle, but that’s not a very big number compared to notch 8.
To tell you the truth, when I read your first post on fuel economy, I began to wonder if all the talk I’ve heard the last 30 years about fuel efficiency really did matter-- because I’d never seen any numbers that put it into dollars and cents. I was taken aback when I ran those numbers to see how much money it really was.
Speaking of D&RGW, I was surprised talking to them about 15 years ago that their F9s, SD9s, and GP9s were NOT 1750 hp locomotives. They had reset them from 835 rpm to 800 rpm, dropping horsepower to 1500, in order to get better longevity. (A tugboat machinist I once knew told me that a 567C run at 800 rpm would run forever, but that he really preferred Alco 251s, because they had to be bolted back together so much more often – lots of overtime!)
D&RGW also put D liners in their 567Cs because they had bigger cylinder ports, so pulled in more combustion air, which helped make up for the thinner air at high altitudes.
Like you said earlier, it’s all a matter of value.
[:)] OK, Mark … comes from having a career Naval Officer as a father - one who came up through the hawse pipe. So, unless I am invited to use the familure form from, as in your case, the editor of the magazine
Eric: This is an interesting coincidence. My father was also a career officer, though in the Army, and also up from the ranks; in fact, when he was commissioned in 1940, he was the youngest commissioned officer ever in the Army. He served through WWII and the Korean War, on Omaha Beach the afternoon of the first day. His education was practical, and so of course, was mine, learning construction beginning at age 6. I take it you work(ed) for SP; I worked for KCS.
The only thing I know that D&RGW did differently with its SD40T-2s was the water cooling on the radiators, and the application of Vapor Corp.'s PTC, which made them equivalent in tractive effort to a Super Series locomotive, such as an SD50. I think that is the sole difference, but who knows, maybe they used different injectors or governor settings, too. Everyone I knew was really, really happy when the AC4400CWs showed up, because they REALLY pulled, and had air-conditioning and a nice cab. No worn-out weather-stripping on the doors.
Alaska Railroad used PTC as well, but I don’t think very many other railroads did this at the time. Later, SP used Maxitrac (spelling?), which was the same thing as PTC, but probably a better piece of electronic hardware. WC used Q-Tron, also the same thing, but even better, because it replaced most of the electrical cabinet.
I should add that I also enjoy these conversations. Unlike many railroad forums, this one has turned out polite, friendly, and generous – and that’s because of the people who use it, not anything we do at Trains.
Guys,
This is the most interesting thread I’ve read in a long time! I’ve just finished working with the Royal Australian Navy, (as a civilian engineer) and one of my more recent tasks was to evaluate fuel consumption for proposed destroyer type ships. What Mark Hemphill needs is an “operating profile” to base his calculastions on. This would indicate a typical day’s operation for a locomotive, give throttle notches and time spent in each. That’s all you need, along with a fuel consumption graph showing throttle notches. I’m sure I’ve got one for the marine version of the 710 (although I’m not sure they use notches), and I might have a railroad one too. A profile might be able to be downloaded from a modern microprocessor unit - is there anyone in a railroad with access to these things?
The fuel consumption curve for the turbocharged EMDs is very distinctive, with a definite break at the point the turbo takes over from the gear drive. Below that point, it is much like the 567C in an SD9.
A note to carnej1: you said that CP hadn’t fitted their units with an HDL. I assume you meant 265H. The HDL was the GE engine of equivalent power, now out of production, apparently. Has anyone any hard data on the new GE “Evo” engine yet, by the way?
The main problem with the 20 cylinder engine was the length of the crankshaft, and it tended to “twist” while running, called torsional vibration. This was supposed to be absorbed by a torsional damper, but this gave problems on the 20-645E3.
I was shown through La Grange in 1977, and about a third of the engines being repaired were 20 cylinder engines, although they would have been a very small percentage of production.
I hope this adds something to the discussion!
Peter