SD80MAC rebuild program

Trains Magazine Locomotives
1

In LocoNotes yesterday (Sean Graham-White, sourced from AltoonaWorks):

NS is about to commence their SD80ACU program which takes SD80MACs and puts them through a program similar to the one that converted SD90MACs to SD70ACUs.

  • Each unit to be overhauled before the actual rebuild to SD80ACU - Old cab replaced with EMD isolated SD70ACe cab with completely new wiring and electronics

  • ICE (Integrated Cab Electronics) displays replaced with FIRE (Functional Integrated Railroad Electronics) displays with new EM2000 to replace old EM2000

2

Is any work done on the traction motors? Other than cleaning and perhaps polishing?

3

I’m glad they’re getting rebuilt. Also glad I got to run them in their original form (even if they were getting kind of beat).

Just something about them I like. Maybe it’s the old style EMD widecab with big teardrop windshields? They were beasts (I never got to run a true 6000hp 90mac or AC66whatever). I have run a 70ACu (rebuilt sd90) on a local already. Impressive engine - but not quite the same level of a 80mac. Guess it’s just a personal thing. Something about them.

4

Here’s a view you don’t often see:

[This was a picture taken from the B-end; the forum software has removed the URL at some point since the post was originally made]

5

Because they’re running locomotives most likely already on a schedule mainteance for the TM combos. Class 1’s generally change them out every 3-4 years it looks like for mainline locos, TM’s dip, bake, new bearings, new wheel set. That schedule could coincide with the engine work.

6

Will the extra weight and added horse power increase their tractive effort (starting and continuous)?

7

The HP won’t do anything to raise the starting or continuous TE, but the extra 12,000# will give it a little bump, maybe 4-5,000#. That’ll get one more loaded car up Horseshoe Curve.

8

[quote user=“Overmod”]

In LocoNotes yesterday (Sean Graham-White, sourced from AltoonaWorks):

NS is about to commence their SD80ACU program which takes SD80MACs and puts them through a program similar to the one that converted SD90MACs to SD70ACUs.

  • Each unit to be overhauled before the actual rebuild to SD80ACU - Old cab replaced with EMD isolated SD70ACe cab with completely new wiring and electronics

  • ICE (Integrated Cab Electronics) displays replaced with FIRE (Functional Integrated Railroad Electronics) displays w

9

At 5500 HP, might they be considering using pairs on intermodal trains between Chicago and New Jersey after they are overhauled and theoretically more reliabile? Could they get a “2 units replacing 3” on some trains?

10

Does NS still have SD80MACs in thier roster? How many are being rebuilt.

It’s nice that both the SD70MAC and SD80MAC are getting rebuilt instead of scrapped, to me that’s always a plus.

11

The SD80MAC’s are still active. I saw two over the last few days on my ride home from work.

12

Last I heard SD80MAC overhauls were postponed by NS, no perticular reason why. From NSdash9.

13

Likely because like most railroads NS is so short of power they are leasing old ex-CSX GEs.

14

It seems like it may not me a “huge” upgrade; but a lot of those little things make a massive difference in the reliability of the unit, getting rid of the siemens inverters and dumbing the old fire screens should make a much better locomotive out of them.

15

Where on NSDash 9 is that information? I can not find it.

16

80 MACs updated should be good things . I always thought that the 20-710 was a better bet than the 265H and I’m surprised EMD went away from something the railroads were accustomed to - 2 strokes . I do remember earlier on the issues with 20-645s but they got around that with a bit of extra development .

I would like to have seen the roads revert to the 20 rather than rebuild the big block 90s with 16-710s , its not a whole lot less horsepower but it is familiar territory .

Out of curiosity what did EMD do with the 20-710 to get the extra 500 ponies out of it ?

17

The same way they got 4300HP out of the 16-710.
They increased the maximum rpm to 950 from 904.

Peter

18

I find it interesting that even after NS uprates them to 5,500 as part of their ACU rebuild, they’ll still be producing less power per cylinder than the 16 cylinder models in the SD70ACU’s. 275 hp per cylinder versus 281.25 hp.

I suspect EMD/Conrail played it very safe by just rating them at 5,000 hp, perhaps with the intentions of doing something similar themselves after a few years of service proved the soundness of EMD’s 20 cylinder engine.

But then Conrail disappeared and EMD lost their SD80MAC advocate.

19

Maybe at the time EMD wanted to show the thousand traction horse power advantage the H version was intended to have .

The fuel usage thing may have been a concern at the time too .

Anyway it will be interesting to see what the operators think of the 5500 Hp compared to the defacto 44/4500 Hp units atm .

20

Well hopefully the 80s radiators can support 5500 Hp reliably because the word is that it didn’t work out so well cooling wise with the H engine .