I don’t get every month of Trains magazine, nor do I read every article. I do remember engines getting up to 6000 hp and talk of up to 8000 hp. But aren’t most new engines around 4000 hp now?
for the most part the new engines are 4400 and its been some time since i had a 6000 hp unit, I am only a engineer so i am not sure what engines are made anymore, I am not sure why sd 90mac engines are not made they are great engines i had a Union Pacific unit and it just ran circles around the ge versions with so much power i didnt need much over notch 4-5 to get to and stay at track speed.
There is also the AC6000CW. Csx has alot of them. It rates at 6000hp as well as the SD90mac. Not sure when it was quite being made. GE started production in 1998. Now they are producing only GEVOs.
Overkill,
There is no real use for a 6000hp single unit.
You could pair them up in coal drags and grain trains, or on a stacker, but that’s about the only real economical use for them.
You can get 6000 hp from a three unit SD 40-2 MU, and if need be break them up and use each locomotive for a lot of other, less HP intense purposes.
The SD90s are great, I have even flat switched with one…they load up and get going a lot quicker than you would think for their size, and they will stop on a dime…but 6000hp in switching service, or on a local industry drag is just a waste of fuel and horsepower.
I can take four of our MK1500Ds, MU them, get you 6000hp, with 16 traction motors as opposed to 6…and when you get to where you are going, you can bust up the MU, and have four 1500 hp units able to go anywhere you need them to, and perform just about any service you want.
You can liken the 6000Hp units to the Gas Turbines UP had…big, single purpose 8500hp locomotives designed for hauling big tonnage up hard grades, very labor intensive and costly, and in the end UP still had to add diesel helper units on to the trains…and when the traffic patterns changed, UP was stuck with these units, and had no real use for them.
Think of it like this…
You could use the Queen Mary to go bass fishing, but you would be hard put to find a big enough lake!
But for the same cost, you can buy a whole lot of bass boats and fish a whole lot of different lakes!
Bombardier-Alstom HHP-8s have 8000 HP and are used for pulling passenger trains on the Northeast Corridor.
Did any of the SD90’s even have 6000hp? When the unit came out it had around 4000hp but emd developed an engine later on that had the 6000hp but i didnt know that any of the railroads upgraded their 90’s?
Wasn’t that the SD90/43MAC?
Yes, 62 were built for UP with the H engine, of which they still have 21. Canadian Pacific also picked up 4. EMD leasing has 41 ex UP locomotives
From what I understand the 6000hp engines didn’t catch on and were having problems, so the railroads stayed with 4000-4400hp. I know CSX depowered at least some of the AC6000s, don’t know if they returned them to full rating or not. It seems every time the horsepower race gets really crazy that they have to let up, after all isn’t that what happened in the SD45 era?
As I recall the problem with the SD45 was the 20 cylinder crankshaft and not the horsepower. The PRR centipedes (1945 or so were permanently coupled 3000HP engines for 6000 total HP) after removing the turbos they were 5000hp. I think some people are starting to wake up and realize there is no secondary market for these huge engines. They are only good for hauling tonnage on through freights and I doubt there is a class 2 or shortline that will have any interest in them when the 15 year depreciation is up.
nanaimo73’s numbers are correct - a bit more Info:
62 delivered UP with the 6000 hp H engine, of which they still have 21. EMD leasing EMDX has the 41 ex-UP locomotives - returned following expiration of the original lease. Canadian Pacific also picked up 4.
UP Big Macs wear roster numbers 8911-8931. CP quartet is numbered 9300-9303.
What changed? When did UP start having “no real use” for an 8500 hp 12-driving-axle unit?
It seems to be a given that 6,000 horsepower is too much, and that the 4,300/4,400 hp range is best for now. However, what about the ex-Conrail SD80MACs rated at 5,000 hp? How did these units work for Conrail and its predecessors?
There were about three 6,000 horsepower products released. The GE AC6000CW, the EMD SD90MAC and the EMD SD90MAC-HII. The GE AC6000CW seems to be the most successful out of all three of the units with CSX having 117, Union Pacific having 186 and BHP Iron in Australia having 8. Plus, you can count the GECX 6000 demo unit, titled the “Green Machine.” I don’t keep up as much with the EMD SD90 series, but I know Electro-Motive Leasing (EMLX) has the 41 former UP SD90MAC-HII locomotives. The SD90MAC-HII was a very unsuccessful locomotive, and Canadian Pacific and UP owned them. Not sure what CP has or is doing to there’s, but UP sold all. 6 EMLX SD90MAC-HII units are roaming my area of Northeast Ohio on the Wheeling & Lake Erie Railway and the W&LE seems satisfied with them.
My favorite out of the three is the GE AC6000CW. CSX derated most of the fleet to 4,400 horsepower and retitled them CW44-6AC units in the year of 2000, 2001 or 2002. Later on, CSX rerated the units to 6,000 horsepower. CSX uses these units in intermodal traffic, and on occasion, some other types of loads. CSX likes to keep the AC6000CW’s paired up and when they are, they can be quite a team. At full speed, their “turbo chargers” make a recognizable ‘whining’ noise. I have heard positive comments on these units from crews and also heard that they are alot more reliable than EMD’s competitive product. I also have not heard much talk of them having problems from CSX.
Just my two cents.
IMHO, the gas turbines were a product of the steam-age method of operating, where a locomotive rarely left a certain territory.
Today, as we all know, run-through power is the norm, so having locomotives that just about any shop can work on is a plus. As exciting as it would be to have some unique UP (or any other road) loco show up in your area, it would be a nightmare for the local shop if they had no clue how to deal with a problem with it.
I really don’t know when the philosophy (limited territory vs free roaming) made a wholesale change. Maybe someone has an idea.
I’ve heard that with the 6000hp units that 1000hp on each axle has been a problem with, keeping the traction, especially in inclement weather. I believe the GE units have a little better traction control regarding the hp per axle but they still have some problems with traction on wet and icy rail. Ive been on UP’s 6000hp units both 90mac and ac6000, great enignies for coal trains, and the dynamic braking in these locomotives are excellent.
As was said earlier more axles for the horsepower does seem to be better, fewer issues with slipping, and just that much more contact with the rail for starting especially.
IIRC, the turbines burned a type of fuel (bunker oil maybe?) that was really cheap at one point. I seem to recall that whatever it was is important to the plastic industry and so when the plastics market really started booming, the price of bunker oil/whatever went through the roof.
I also seem to recall that turbines are most efficient operating near their full potential. I think they burn a rather large amount of fuel whether running light or with a heavy train behind them. I’m not sure if that helped to their demise or not.
Finally, I think the diesel era brought a lot of standardization with it, and so having this set of highly specialized, non-interchangeble locos didn’t make a lot of sense. Even when the UP brought out the dual-engine locos, they had at least some parts interchangability with their single engined kin.
As an aside, before their final exit, didn’t the UP/GE upgrade a few of the 8500HP turbines to 10,000HP?
UP’s gas turbines did burn Bunker C, which comes off near the bottom of fractionation, I’m not sure that any petrochemicals use it as a feedstock. At the tail end of the steam era on UP, bunker C fueled oil-burning steam, so fuel issues were minor for the turbines. Some of the big turbines were indeed upgraded to 10000 HP.
the main reason for not using a turbine engine is reliablity a modern diesel engine in a semi can go 50,000 to 100,000 mile between oil changes and doesn’t need any servicing until 1 million miles
I guess the solution to slipage would be to add another couple of axles, an 8 axle 6000 hp AC loco instead of a 6 axle. Unfortunately, the added traction motors would probably make the loco more complex and add additional weight, like UP’s double-diesel experiments in the 1960s.