which turbine in UP turbine

Trains Magazine General Discussion
1

I’ve been trying to find out which turbine they used in GE 8500 hp turbines (and in earlier models)

This site link (oil aditives manufacturer for turbine engines) mentions clearly that a GE “frame 5” turbine was installed into UP 8500hp locomotives.
There is another site which said the same thing.
And there is this site: link2
Which says GE made 12 of Frame 5 turbines for union pacific before 1973

Now there is one big problem:
“frame 5” turbine is a name for “Model 5000” series.
The weakest turbine in 5000 series is MS5001 (still made), single shaft turbine that makes 36 000hp at maximum RPM.
I think it’s small enough to fit in a locomotive, but its just too strong.

Now here are the possible answers to this puzzle:

  1. A frame 5 turbine was used, but it was modified to output 8500hp at max RPM (lowered fuel consumption)

  2. A frame 5 turbine was used, but the locomotive was made such that at full throttle it doesn’t spin the turbine at its full RPM, but at maybe little more than 20% of full RPM
    Which I think I can rule out, because UP turbine rolled at 4860 rpm, and if it were MS5001 it would output a lot more than 8500hp because MS5001 full RPM is about 5100 rpm

  3. The data in above links is false, a custom turbine was used

does anyone know for sure what was the name of the turbines used in any of UP turbine locomotives?

thanks

2

I can’t tell you about the authenticity of the info above, but 4800 RPM for a turbine? That seems a bit low. Most turbine engines I’ve seen spin somewhere in the area of 100,000 RPMs and up, and have a very narrow powerband … i.e. the turbofan engines on jetliners “idle” in the area of 80% max RPM.

3

I’m looking at data for all industrial turbines currently manufactured by GE, and I think you have a wrong idea about it, powerplant turbines are a bit different from aircraft engines.

The RPM’s are from 3000 for the strongest one, to about 16 600 for the weakest turbine model.
It seems the more powerfull ones work at lower constant RPM.

So around 5000 for engine turbines is a realistic RPM

4

Frame 5 turbines used in power plant peaking units ran at 5106 RPM. A reduction gear lowered the speed to 3600 for the generator shaft. The output was 17 to 23 megawatts depending on the air inlet temperature, relative humidity, and barometric pressure.

5

well anyway, here is the turbine used in the locomotives, this its a miniature with simplified detail, but done to scale:

picture1

and here is how the Frame 5 turbine looks like (hard to tell though)

picture2

It’s the same kind of structure, and the size is about the same, but all GE turbines of that power and size look similar. Difficult to tell.

Now if those Frame 5 turbines shipped to UP weren’t used in Big Blows, where the heck did they put them? :-S

Anyone recognize the turbine on the first picture. Or is it mentioned in any of the books about UP turbines, which prime mover they used.

6

One other problem is that the Union Pacific had 30 GTEL turbines not 12. Last ones were built in 1961.

7

Yea, I’ve mentioned that

Maybe someone with a good book on turbines will come by and tell us the name of that turbine, if its a standard model, and if its a no-name custom model, I’d like to hear some specs.

8

This is translated from German from Wolfgang Stoffels “30 Jahre Gasturbinen lokomotiven 1932-1962”.

It had a 16 stage axial compressor and a two stage turbine. The whole turbine group (presumably including the generators) was 6 metres long. There were ten combustion chambers arranged around the compressor with counterflow of combustion air. The power was 8500HP at a speed of 4870 rpm The gas temperature at turbine inlet is 770 degrees celcius, at exit 450 degrees C. Airflow was 3750 cubic metres/minute, fuel consumption 3300 litres/hour or 350 grams/ HP hour. The pressure ratio is 6.5. These turbines had their power increased to 10 000 HP but I have no details after the change.

M636C

9

Something to keep in mind is that most turbines are rated at “STP” conditions, that is sea level at 59F. The turbines used in the Big Blows were rated at 10,000 HP at 8,000’ (for pulling trains over Sherman Summit) and 80 to 90F - their power at sea level and 59F would have been higher.

GE has made some impressive progress in turbine efficiency (and I’m not saying that because I work for GE), their H series have 46% efficiency at full power and over 40% at half power.

10

I keep seeing people saying that the 10 000 hp upgrade is a myth and that it never took place.

Can someone tell me where did that information come in the first place?

11

The limiting factor for any rotating engine (gasoline, diesel, or turbine) is centrifigal force. A rotating mass generates internal centrifugal stresses that increase with increased speed. These stresses cannot be tolerated if the internal stresses exceed the yield stress limit of the material. Consequently, larger engines always operate at a lower rpm. There are 100,000 HP marine diesels that are so large that they have access doors in them big enough for a man to go through and do an internal inspection of the engine (when it is turned off and cooled down). These engines generate their full power at only 150 RPM.

12

So

So what exactly would be the increase in power in percentage from say 80F and 8000’ to sea level and 59F?

13

While not “in the first place” “The Union Pacific Diesel” by Dr Cinthia Priest (1999) says on page 182 “in 1962 a program was initiated by the railroad to increase the horsepower rating to 10 000 HP.”

Most of the other references say the same, so if it isn’t true, it is a widespread misapprehension.

It would be fairly easy to increase the power by 1500HP if the turbine was not fully rated initially but improvements in turbine blade coatings and materials would allow this when turbine blades were renewed anyway.

Did you ask the people that were saying that it was a myth where they studied engineering?

M636C

14

When the turbines were new, Trains said the 8500 hp rating was at 6000? ft and-- 90 degrees F as I recall. They said the turbine itself was good for 10700 hp (?) at sea level. The turbines didn’t originally have transition, and their power dropped sharply above 40 mph or so-- as I recall they were down to 3500 rail hp at 65 mph.

So maybe the “upgrade” wasn’t an upgrade of the turbine at all, just an upgrade of the transmission to allow 10000 hp at sea level?

15

Nobody said it’s impossible. The book “Turbines westward” says its a myth, or so the people who read it say, I haven’t read it myself

16

M636C has the right dope on the 8500 turbines. They were two bearing machines as opposed to the 4500HP which were 4 bearing. They did have transition. The horsepower was limited electrically to match the ratings of the tractionmotors (GE752). I worked at GE when the 8500HP were delivered in 1958.

17

Most myths and legends have some seed of truth in them. That UP talked about upping them to 10,000 may be that seed.

18

so can you shed some light on the main issues at hand?

Was the turbine a modified standard industrial turbine (and which), or one that was designed from scratch just for the locomotives.
And what did UP use those 12 frames 5’s for? Did they have powerplants of their own for some use?

And what was the true power of those turbines at sea level and standard temperature?

thanks

19

The pentrex DVD shows them even in LA. they visited lots of places. So that means in places like LA they’d have more HP than in their hometown.

20

There is an illustration of the UP 8500 HP turbine unit on page 185 of Cinthia Priest’s “UP Diesel Vol 1” and it is identical in all important respects with the “model 5001” in the illustration in your link. This is consistent with my description earlier which perhaps you didn’t understand sufficiently. The UP turbines probably preceded the development of industrial turbines, or at least before standard models were introduced.

However, do you have a date for the 12 “Frame 5” units supplied to UP? They might just be the last 12 rebuilt turbines supplied for the 30 units. I suggest that these always have been “Frame 5” units but only the last 12 rebuilt units were actually classified as such because the description was not previously used.

The discrepancy in power between these older units and present “Frame 5” turbines would be due to the limiting temperature of the older materials used in the turbine blades of the 8500 HP units. As I said earlier, the increase to 10 000 HP input to the generator would have been achieved by increasing the fuel flow and the inlet temperature to the turbine, which would require better turbine blade material. The high ratings of current “Frame 5” units are the result of further developments in