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GE donates AC6000CW demonstrator 6002 to the Lake Shore Railway Museum

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Posted by D.Carleton on Tuesday, March 22, 2022 6:13 AM

YoHo1975
Were the inverters a limitation for both manufacturers?

When Seimens was upgrading the Sacramento plant to build the ACS-64, the German VP who came over to oversee (Who is not the person currently overseeing it) the upgrades was a member of our club. He had STRONG opinions on the drivelines in the SD90s and SD70MAC as you might expect. He was of the opinion that the Siemens gear could more than handle the SD90 output.

EMD's MAC series had GTOs. The ACE series, retreads and DC-to-AC conversions are IGBT supplied by MELCO. Same thing with GE except they are providing the new IGBT hardware. GTO has limitations and is not as robust as IGBT but obviously work as they are still in regular service in large numbers all these years later.

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Posted by YoHo1975 on Tuesday, March 22, 2022 10:38 AM

D.Carleton

 

 
YoHo1975
Were the inverters a limitation for both manufacturers?

When Seimens was upgrading the Sacramento plant to build the ACS-64, the German VP who came over to oversee (Who is not the person currently overseeing it) the upgrades was a member of our club. He had STRONG opinions on the drivelines in the SD90s and SD70MAC as you might expect. He was of the opinion that the Siemens gear could more than handle the SD90 output.

 

EMD's MAC series had GTOs. The ACE series, retreads and DC-to-AC conversions are IGBT supplied by MELCO. Same thing with GE except they are providing the new IGBT hardware. GTO has limitations and is not as robust as IGBT but obviously work as they are still in regular service in large numbers all these years later.

 

 

 

Yes I know that, but in the context of the discussion on 1000HP per axle. Did the SD90 have inverter problems in the 6000HP configuration. If it did, it's not something I've heard of. 

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Posted by D.Carleton on Tuesday, March 22, 2022 10:48 AM

YoHo1975
 Yes I know that, but in the context of the discussion on 1000HP per axle. Did the SD90 have inverter problems in the 6000HP configuration. If it did, it's not something I've heard of. 

No, failures of the AC6000 and SD90MAC cannot be blamed on their respective AC transmissions.

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Posted by Erik_Mag on Tuesday, March 22, 2022 11:09 PM

D.Carleton

EMD's MAC series had GTOs. The ACE series, retreads and DC-to-AC conversions are IGBT supplied by MELCO. Same thing with GE except they are providing the new IGBT hardware. GTO has limitations and is not as robust as IGBT but obviously work as they are still in regular service in large numbers all these years later.

My understanding that GTO's themselves are robust, but the associated circuitry may not be very robust. The turn-off process for a GTO involves pulling about one third of the current passing through the GTO through the gate (hence Gate Turn Off thyristor), which could be several hundred amps. Turning off an IGBT involves pulling out a few amps for less than a hundred nano-seconds. Overall turn-off time for an IGBT may be on the order of a micro-second needed to sweep out minority charge carriers - which is a similar process to reverse recovery in a junction diode.

Another limitation of the GTO is that it they are slow, with maximum switching speed not much higher than line frequency. Locomotive size IGBT's can switch at a few kHz.

IGBT's are easier to use in a inverter per axle arrangement than GTO thyristors.

BDA
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Posted by BDA on Saturday, March 26, 2022 5:17 AM

Yes 90 MACs did have problems from time to time .

I had one let go coming out of Anderson Point one morning .

Another time had a H let go in a big way on a 40,000 tonne ore train out of the Creek . I was amased the almighty lurch didn't break the train . 

Also was involved in a load test with a pair of 90 MAC Hs , one in 8 against another in DB8 . The one in power let go and I nearly went through the back wall of the cab .

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Posted by SD70Dude on Sunday, March 27, 2022 1:48 AM

Museum press release from a few days ago.  6002 does still contain a HDL engine.

http://www.rypn.org/forums/download/file.php?id=22649&mode=view

http://www.rypn.org/forums/download/file.php?id=22650&mode=view

Greetings from Alberta

-an Articulate Malcontent

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Posted by SD70Dude on Sunday, March 27, 2022 1:53 AM

BDA

Yes 90 MACs did have problems from time to time .

I had one let go coming out of Anderson Point one morning .

Another time had a H let go in a big way on a 40,000 tonne ore train out of the Creek . I was amased the almighty lurch didn't break the train . 

Also was involved in a load test with a pair of 90 MAC Hs , one in 8 against another in DB8 . The one in power let go and I nearly went through the back wall of the cab.

How exactly did they "let go"?  I love gruesome details about mechanical failures.....

I've always gotten the impression that out of the two 6000 HP designs, GE had the worse diesel engine but EMD had the worse overall locomotive. 

Greetings from Alberta

-an Articulate Malcontent

BDA
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Posted by BDA on Saturday, April 2, 2022 10:33 PM

The first one out of the Port lost an inverter and under relatively light load , it was the middle of 3 units . Basically squeeled in fright . 

Went back identified the fault (one inverter) and isolated it . Control asked if I cut a traction motor out , no cut an inverter or effectively 3 motors or one truck out .

Second time had 3 units on 42 000 metric tonnes , Dirty Harry was again in the middle and let go under full load at about 20-25 km/h . The sensation was a almightly reef then back to the other two units . As I said I was surprised it didn't break a nuckle or drawbar given the trailing tonnage involved . The unit was isolated and went through with the other two , which from memory was a 70ACe and a Dash 9 .

The last one involved a couple of 90Hs in a yard . The idea was to have one loaded in run 8 against another in DB8 . Noisy as you'd imagine and short lived as the one powering in 8 , probably at 7-8 km/h , let go and offloaded very quickly against the other loaded up in DB8 . As mentioned it stopped so quickly I would have slamed into the back wall of the cab if I'd not braced myself .

I personally don't agree that the H engine itself was the only issue with these units . At the time it was said that the Siemens control system was not as evolved as it could have been , also whispers that the relationship beetween them and EMD could have been better .

We mostly ran units converted to the 16-710 and while more reliable they still seemed fragile control system wise . As I've mentioned in other threads that Earthquake effect was not fun though it didn't happen all the time . Basically the control system cycled through rapid on and almost off load and the isolated cab danced around with everything (human and otherwise) trying to shake itself to pieces . 

A little off topic but I think EMD would have been better off trying to refine the SD80MACs , the 20-710 was a lot less problematic and a control system upgrade ACR style would have made them a far better thing . I guess the proof is that 80MACs are still around ? 90MACs and AC6000s are not .

IMO the ony way you will effectively utilise much more than 4500 Hp is with heavier locomotives , traction control systems can only do so much and then there's nowere to go but higher axle loads .

      

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Posted by BDA on Saturday, April 2, 2022 10:35 PM

 

      The first one out of the Port lost an inverter and under relatively light load , it was the middle of 3 units . Basically squeeled in fright . 

Went back identified the fault (one inverter) and isolated it . Control asked if I cut a traction motor out , no cut an inverter or effectively 3 motors or one truck out .

Second time had 3 units on 42 000 metric tonnes , Dirty Harry was again in the middle and let go under full load at about 20-25 km/h . The sensation was a almightly reef then back to the other two units . As I said I was surprised it didn't break a nuckle or drawbar given the trailing tonnage involved . The unit was isolated and went through with the other two , which from memory was a 70ACe and a Dash 9 .

The last one involved a couple of 90Hs in a yard . The idea was to have one loaded in run 8 against another in DB8 . Noisy as you'd imagine and short lived as the one powering in 8 , probably at 7-8 km/h , let go and offloaded very quickly against the other loaded up in DB8 . As mentioned it stopped so quickly I would have slamed into the back wall of the cab if I'd not braced myself .

I personally don't agree that the H engine itself was the only issue with these units . At the time it was said that the Siemens control system was not as evolved as it could have been , also whispers that the relationship beetween them and EMD could have been better .

We mostly ran units converted to the 16-710 and while more reliable they still seemed fragile control system wise . As I've mentioned in other threads that Earthquake effect was not fun though it didn't happen all the time . Basically the control system cycled through rapid on and almost off load and the isolated cab danced around with everything (human and otherwise) trying to shake itself to pieces . 

A little off topic but I think EMD would have been better off trying to refine the SD80MACs , the 20-710 was a lot less problematic and a control system upgrade ACR style would have made them a far better thing . I guess the proof is that 80MACs are still around ? 90MACs and AC6000s are not .

IMO the ony way you will effectively utilise much more than 4500 Hp is with heavier locomotives . Traction control systems can only do so much and then higher axle loads is the only place left to go .

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Posted by M636C on Sunday, April 3, 2022 5:39 AM

I personally don't agree that the H engine itself was the only issue with these units . At the time it was said that the Siemens control system was not as evolved as it could have been , also whispers that the relationship beetween them and EMD could have been better .

You have to admit that FMG's SD90MAC-H units weren't exactly fresh out of the Factory... All of them had been discarded by UP as too much trouble. Only a few of them were rebuilt at Juniata with 16-710s (and those had the Juniata "AC" symbol on the cab side.). The locos with the 265H basically got a coat of paint...

They were bought to ship ore during the mining boom and most days they did that. FMG earned a lot of money from them, even those with the 265H. When the boom ended they were stored. Now the Brazilians found that they couldn't build tailings dams twice, FMG are running anything they can lay their hands on including very sad looking Dash 8s still in BNSF paint.

There are serious rebuild units coming from GE with new FDL enines, new inverters and AC6000 radiators (so something lasting came from that program, with 150 radiators of AC6000 design running on EVOs in the Pilbara already).

I recall a day on the Mt Newman line when it was raining on the Chichester range* and we had tumbleweed blowing across the track. and the two C636s trailing had no sand. We had 144 wagons, so maybe 20 000 tonnes. Whenever a trailing unit slipped, you could feel the train slow, long before the wheelslip alarm bell rang. Eventually the driver made a partial application of the independent brake to control wheelslip. We stopped at the loop at the top of the hill and I was told "go back and check that none of the locomotive wheels are cracked but under no circumstances touch them" while the driver did the other side...

*equivalent to hades freezing over....

Peter

BDA
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Posted by BDA on Wednesday, April 6, 2022 6:28 PM

Yes well both brands of 6000 hp diesels were discarded though quite a few of the 9043s are still running around .

Shame that the ACe type rebuild wasn't available at the time . I suppose you could say that the AC6000 may have had a similar option but no .

Anyway good to see that an AC6000 has been preserved , probably not much chance of a 90MAC H being kept . 

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Posted by M636C on Wednesday, April 6, 2022 7:25 PM

BDA

Yes well both brands of 6000 hp diesels were discarded though quite a few of the 9043s are still running around .

Shame that the ACe type rebuild wasn't available at the time . I suppose you could say that the AC6000 may have had a similar option but no .

Anyway good to see that an AC6000 has been preserved , probably not much chance of a 90MAC H being kept . 

 

My recollection was that the original intention was to rebuild six of the SD90MAC-H units at NS Juniata, and this was to include a complete replacement of the inverters and control system to SD70 ACe standards.

Apparently the first unit was stripped to the frame at Juniata when FMG decided that they needed more power immediately and six more units were obtained intended for delivery "as is".

The first unit at Juniata was felt to be in the best condition of all the units and it was reassembled as it was and was shipped with the first batch. Six units were rebuilt at Juniata with 16-710G3 engines, but these kept the original GTO inverters, probably to allow an early delivery.

So as I understand it, the ACe option was there but not taken up to ensure quick delivery.

Perhaps they learned a lesson and the AC44C6M units coming now are fully rebuilt, although they have bought some used Dash 9s to meet the urgent need for new power.

Peter 

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