EMD Dash 2 question

[GP40]

CSX seems to like their SD70MACs, but they hate their SD70ACes...

In CSX's view, they are both crap products, the only difference being the ACe's are just newer, more expensive crap. CSX's latest big order for more GE products is just the tip of the iceberg. I honestly don't see CSX ordering any significant numbers of new EMDs anytime soon. The 70MACs are going to start to be replaced with the next order of AC GEVOs scheduled for late 2008.

You are the only one saying that, and it seems like you never post unless it's to bash EMD - kinda funny considering you call yourself GP40-2!

Give the guy a break. When EMD starts to make products that are as good or even better than GE I am sure that GP40-2 will again sing their praises. Back in the day the reverse was true but times have changed. EMD has lost its corporate parent General Motors and GE Transportation is now one of the crown jewels in the GE Family of products right up there with the lightbulbs and the jet engines.  

Let's face the new EMD Tier 2 locomotives has got to rank up there with the BL2 as the uuugggliest locomotive to have ever come of the erecting floor at LaGrange Ill. OH OPPs I forgot the haven't fully assembled a locomotive there in nearly 30 years!!!

[silicon212]

CSX seems to like their SD70MACs, but they hate their SD70ACes...

In CSX's view, they are both crap products, the only difference being the ACe's are just newer, more expensive crap. CSX's latest big order for more GE products is just the tip of the iceberg. I honestly don't see CSX ordering any significant numbers of new EMDs anytime soon. The 70MACs are going to start to be replaced with the next order of AC GEVOs scheduled for late 2008.

You are the only one saying that, and it seems like you never post unless it's to bash EMD - kinda funny considering you call yourself GP40-2!

[GP40-2]

CSX seems to like their SD70MACs, but they hate their SD70ACes...

In CSX's view, they are both crap products, the only difference being the ACe's are just newer, more expensive crap. CSX's latest big order for more GE products is just the tip of the iceberg. I honestly don't see CSX ordering any significant numbers of new EMDs anytime soon. The 70MACs are going to start to be replaced with the next order of AC GEVOs scheduled for late 2008.

[f14aplusfl]

I think its a combination of tier 2 existing and having the SD70M and if its AC they denote it.

[EJE818]

CSX seems to like their SD70MACs, but they hate their SD70ACes. They put a -2 in the SD70M-2 becuase they wanted to make it sound as successful as the SD40-2 was. Just kidding about that one! I think it might have to do with the tier 2 thing also.

[broncoman]

... The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

Would that make it a Microsoft product? 

Heaven forbid - that would require OS software patches every two weeks.

 Incorrect.  That would only apply to the SD70XP Professional.  The SD70Me will just simply refuse to work from time to time, needing to have the engine restarted before the alternator would produce power.

 Or would that be SD70M-service pack 2?

[f14aplusfl]

Actually, the guys designing the locomotive probably had Microsoft as the operating system (OS) for their computers.

I don't remember off hand if it was GE, EMD, or both that Microsoft XP was being used as the background OS for the locomotive's control system. Ironically it is "more stable" as the OS can be redesigned specifically for the diesel locomotive. Computer OS typically are "more unstable" is that they have to take into account all the different hardware and hardware configurations on the market

[wctransfer]

Actually CSX has some of the best SD70MACs, beating even BNSFs. They got the "heavy MACs" and all of the engineers I've talked to love them.

Alec

[CNW 6000]

So everything comes with AC power going to the trucks and it's switched/transformed to what's specified at/just before that point?

[beaulieu]

In the upgrade process would a RR want to 'switch' a loco from DC to AC?  Would that mean swapping 'alternator' and 'motors' only or more?  Wouldn't that help a loco in yard service, perhaps?

I think that you are confusing changing the main generator from a DC type, to an AC Alternator with a Rectifier, and a locomotive having an AC traction motors. All locomotives now use an AC alternator to produce the electric power to propel the locomotive, those locomotives designated as "AC" locomotives also use AC traction motors, while those labeled as "DC" use DC traction motors. The reason that the main generators were changed from DC generators to AC alternators is that as the locomotives power rating reached 2800hp. the DC generators became so massive they barely fit inside a locomotive carbody. An AC alternator of similar capacity is smaller and requires less copper. Also the higher capacity of the AC alternators allowed a simplification of the transition stages of the motor connections, as in a GP35 needed to have 25 stages of traction motor transition, while a GP60 has but one stage of alternator transition.

[CNW 6000]

In the upgrade process would a RR want to 'switch' a loco from DC to AC?  Would that mean swapping 'alternator' and 'motors' only or more?  Wouldn't that help a loco in yard service, perhaps?

[Lord Atmo]

 CSX must have microsoft SD70MACs

[oltmannd]

Almost. The GP38AC was the first locomotive with a traction alternator in EMD's lineup, and this preceeded Dash 2 - but Dash 2 saw the entire lineup receive traction alternators.

Hmmm, I'd argue a bit on that. My recollection is that the 40 series all had traction alternators as EMD's traction generator was running out of steam at 2500HP - witness the large number of transition steps on the 35 series to keep the generator voltage and current within limits.

You may be correct in asserting that the GP-38AC preceded the Dash-2's. 

Forgot about the GP38ACs as a variant of the GP38.  The 1965 version of the GP40, SD40, SD45 all had alternators while the GP38 had a generator.  In the last couple of years before the Dash 2 line came out, you could get AC as an option on the GP38....

[erikem]

Almost. The GP38AC was the first locomotive with a traction alternator in EMD's lineup, and this preceeded Dash 2 - but Dash 2 saw the entire lineup receive traction alternators.

Hmmm, I'd argue a bit on that. My recollection is that the 40 series all had traction alternators as EMD's traction generator was running out of steam at 2500HP - witness the large number of transition steps on the 35 series to keep the generator voltage and current within limits.

You may be correct in asserting that the GP-38AC preceded the Dash-2's. 

[YoHo1975]

Yeah, all Dash 2s received Alternators. Not just the 38s.

[silicon212]

Almost. The GP38AC was the first locomotive with a traction alternator in EMD's lineup, and this preceeded Dash 2 - but Dash 2 saw the entire lineup receive traction alternators.

[oltmannd]

This is essentially true.

 

The original -2 signified solid state electronics and computer controlled anti wheel slip. When an older, non-2 is remanufactured with aftermarket versions of this, it's often relabled as -2.

 

The SD70M-2 refers to something completely different though. It's referring primarily to the prime mover change. Though there are other differences. Still, for marketing reasons, they wanted to keep it the SD70. It's still a V-16 710 prime mover.

The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

The guts of EMD's original Dash 2 improvements was that they modularized the electronics.  They took the existing IDAC panel and repackaged it as a WS10 module, for example.  No real improvment in wheelslip performance, but much easier to test and replace.  The same went for the other modules, the sensor, sensor bypass, rate control, etc.  The other big chunk was the HTC truck, which did improve overall adhesion.  The rest of the changes were small and related to easier servicing.  The only other big change - on the 38 series only - was the use of a traction alternator and diodes replacing the DC main generator.

[silicon212]

... The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

Would that make it a Microsoft product? 

Heaven forbid - that would require OS software patches every two weeks.

 Incorrect.  That would only apply to the SD70XP Professional.  The SD70Me will just simply refuse to work from time to time, needing to have the engine restarted before the alternator would produce power.

[CNW 6000]

(Getting ready for flaming...)

Couldn't UP handle that?  LOL!  Sorry, I had to!

[da Milwaukee beerNut]

... The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

Would that make it a Microsoft product? 

Heaven forbid - that would require OS software patches every two weeks.

[CNW 6000]

... The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

Would that make it a Microsoft product? 

[Anonymous]

I have read that the -2 in the SD70M-2 is to show that it is Tier-II compliant.

[silicon212]

This is essentially true.

 

The original -2 signified solid state electronics and computer controlled anti wheel slip. When an older, non-2 is remanufactured with aftermarket versions of this, it's often relabled as -2.

 

The SD70M-2 refers to something completely different though. It's referring primarily to the prime mover change. Though there are other differences. Still, for marketing reasons, they wanted to keep it the SD70. It's still a V-16 710 prime mover.

The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

 

... or SD70DCe.

[YoHo1975]

This is essentially true.

 

The original -2 signified solid state electronics and computer controlled anti wheel slip. When an older, non-2 is remanufactured with aftermarket versions of this, it's often relabled as -2.

 

The SD70M-2 refers to something completely different though. It's referring primarily to the prime mover change. Though there are other differences. Still, for marketing reasons, they wanted to keep it the SD70. It's still a V-16 710 prime mover.

The real question is why the AC version isn't a SD70MAC-2 or conversly, why the DC version isn't an SD70Me. 

[Anonymous]

I think reason for the SD70M-2 being called a "dash 2" is really just that EMD wanted to call it's upgraded SD70M something besides SD70M. The SD70M-2 is different from the SD70M (the Tier 2 engine being the biggest), but not in the same respect as the jump from the SD40 to the SD40-2. They could have just as easily called it the "SD70e" or left it SD70M.

[CNW 6000]

I think I know that the -2 upgrade on EMDs is related to traction and fuel management issues that the original engine was blessed with.  My question is would the upgrade have the same effect from SD40 to SD40-2 as the SD70 to SD70M-2 or something along those lines?  Thanks in advance!