Ok, thanks.
If its not a problem, could you treat us all with a scan of that diagram from the book?
thanks
It is worth mentioning that GE also made some impressive progress in efficiency of their new locomotives. They more performance data we accumulate on the GEVOs (DC version), the more impressive they look compared to the new EMDs. Most railfans know about the new diesel engine, but most don’t appreciate the work GE has put into the locomotive’s electrical system. Even with DC traction motors, the GEVO electrical system can pull continious current for extended periods that will cause the new EMDs to derate in power.
At the time these turbines came into service, they were intended to be a new series of industrial turbines. They were originally supposed to deliver starting summer of 1957 but the turbines ran into many problems, so the first loco didn’t get to the UP until Sept 1958. This allowed steam to last longer than planned. :-). Several blew up either on test in Schenectady or at Erie after they were in the locos. There were 4 GT596 generators run thru a large reducing gearbox. Generator speed was about 1000RPM. I’ll send more info when my typist returns…
any technical data you can give about turine and generators would be appreciated
thanks
You think they had it when new? Transitioning from one generator-powering-three-parallel-motors to two-generators-in-series-powering-six-parallel-motors?
Now there is one thing I’m sure in this picture, even though I’m the one asking questions here and not the expert answering them, and that is that the original UP 8500 had two generators. powered by one turbine
its clearly shown in the prototype miniature model that people from GE and UP are holding in pentrex historical footage.
That is unless the original idea was two generators, and the early ones came out with one for some reason
Two 4250 hp generators? In 1958?
Hey, I’m just guessing by the pictures…
go to the previous page and find a link “picture1” in the first couple of posts
you can’t see it that well from that angle, but the model has two identical generators side by side.
Maybe the actual locomotive was built differently, but that’s the original concept
So, what are you saying, what would be more realistic for 1958?
Four generators.
So what are you suggesting, that there were two in separated coil systems in one shell in each of the two generators making it 4 or that the prototype miniature is not what actually ended up being built?
In that picture, what you’re seeing as a generator is two generators end-to-end. With the two armatures on one shaft running thru the two generators, I assume.
There were 4 generators. They were coupled large ends together, into the gear box. The commutators were at the outside ends, and there were two sets of two across the width of the car body. As far as I know the turbines used were all the same type. They may have changed model number at some time.
As an asibe the last group of turbines built between '58 and '61 later had additional traction motors added to some of the fuel tender axels on a few units.
If they added motors, must have been four of them? So each generator had to supply four parallel motors instead of three? Wonder if the generator had the amperage to supply full current to four motors.
(Wonder how they divided up the motors-- one generator for the tender and the other three generators each powered one C truck plus one motor of the fourth truck?)
This is interesting. How did that affect overall power? Any more info on that?
Also, just to keep this thread alive
M636C, could you scan that diagram for me?
Dave E, you said to say more when your trypist returns (don’t know if that was a joke or you were being serious though). Do you have any more specific info to ad?
thanks very much
The only details I have are from Louis A. Marre “Diesel Locomotives: The First Fifty Years” who states these were not as built but added later and not applied to all units that were built as the cab-turbine-tender consists. Maybe this was done when uprated to 10K HP to try to harness the additional power? Since it was not done to all units it may have not have had the desired results?
No, sorry, I don’t have convenient access to a scanner.
But there is very little difference between the turbine diagram shown in “The UP Diesel” and the one you posted. The inlet ducting looks a bit different and the UP diagram shows an angled exhaust duct. The diagram doesn’t show the generators or the reduction gear, just the turbine itself. I guess the generators were coupled up to the shaft which has the diesel starter on the 5001 diagram.
Apart from the ducting changes, the diagram is the same.
Given that most GE generators were capable of providing power to at least four 752 motors, there would be no problem fitting a total of sixteen motors to the turbine, as long as suitable trucks were fitted to the tender, I guess. I’m not familiar with the model GT 596, but the GT 586 powered six motors in the Century 628 without much trouble.
The power limit for DC generators in locomotives was about 2500 -2750 HP and above this both GE and EMD had to change to alternators, in GE’s case the GTA9 and GTA11. GE generators were generally single bearing machines that bolted up to the diesel engine. In the turbine, the end that would have coupled to the diesel was connected to the other generator, so it might have ended up with only two bearings n the pair. This was a difference to EMD, who build two bearing generators and alternators which are separately bolted to the frame. This means that the torque between the diesel and generator goes through the locomotive frame, which doesn’t happen with the GE arrangement.
So for an 8500 HP loco in the 1950s, GE had no choice
I looked up the spec’s in Turbines Westward by Thomas Lee, sea level 59F power was 10,700HP and the 8,500HP rating was at 6,000’ and 90F. Turbines lose power faster with increasing temp and altitude than turbocharged diesels.
My memory may be playing tricks on me, but ISTR that the Big Blows used a larger traction motor than the 752. (780?)
The issue with DC generators is that 2750 HP is about the largest that would fit within a carbody - and also the largest that was compatible with the speeds of locomotive diesels. As power goes up, the diameter also goes up (mainly because the commutator needs to get bigger) and maximum speed goes down. The generators on the C.U.T. M-G sets were capable of handling 6000 HP each (two wired in series for 3KV - short term power output for the set was 9MW or 12,000HP), but they operated at 360 RPM (and looked like 10’ diameter).
The other PITA with DC generators was getting high current for low speed and high voltage for high speed (hence the many steps in transition for the 2500HP lcomotives, e.g. GP-35, SD-24, etc). It is easier to design an al
[quote user=“erikem”]
My memory may be playing tricks on me, but ISTR that the Big Blows used a larger traction motor than the 752. (780?)
The issue with DC generators is that 2750 HP is about the largest that would fit within a carbody - and also the largest that was compatible with the speeds of locomotive diesels. As power goes up, the diameter also goes up (mainly because the commutator needs to get bigger) and maximum speed goes down. The generators on the C.U.T. M-G sets were capable of handling 6000 HP each (two wired in series for 3KV - short term power output for the set was 9MW or 12,000HP), but they operated at 360 RPM (and looked like 10’ diameter).
The other PITA with DC generators was getting high current for low speed and high voltage for high speed (hence the many steps in transition for the 2500HP lcomotives, e.g. GP-35, SD-24, etc).