SD60M / SD60 MAC (What's the difference? )

[Anonymous]

I looked at several pics and still can't see the difference between the two. Is there any at all ? Is it blatant or minor? What's the deal with these 2?

[SSW9389]

Atrain the differences are mostly internal. The difference is in the drive system either a DC drive in the SD60M or an AC drive in the SD60MAC. The other really big difference is that there were only four SD60MACs built as demonstrators before the model was superceeded by the SD70MAC. A total of 460 SD60Ms were built. Diesel data from A J Kristopans EMD Serial Number Page.

[trainfan1221]

It gets more confusing if you throw in the SD60I, which was developed by Conrail with an isolated cab for less noise.

[waltersrails]

could not agree more.

[Anonymous]

SD60 ------standard cab. DC traction motors.
SD60M ----north american saftey cab. DC traction motors.
SD60MAC -north american saftey cab. AC traction motors
AC locomotives can lug more than DC locomotives.

[icmr]

I think I will have to agree with........................................hmmm.............................MAC=AC, M=DC.

Sorry, I just had to do it.



Victor

Happy Railroading.[swg][swg]

[Anonymous]

The SD60MAC is longer than the SD60M, just as with the '70's. The difference can be seen at the rear of the long hood where there is some additional length behind the radiators.

http://www.railpictures.net/viewphoto.php?id=97327
http://www.railpictures.net/viewphoto.php?id=90998

[Roger38]

The only four SD 60 MAC's were tested on the BN, and lettered for Seimans, EMD, and BN. 9500-9503. They were a different paint scheme and different shade of green then BN units. Per the DelGrosso 1994 BNSF annual page 158, they were also 4000 HP as opposed to the 3800 of the SD 60 M. My brother and nephew and I viewed them and took pix in July 1994 the day that the Paul Harvey announcement came over the radio that BN was buying the ATSF. We were at Belmont on the bridge watching the SD 60 M's and 2 SD 70 MAC's on coal trains. Also got to tour the inside of the SD 70 MACS that week. I have slides, but they aren't where they are supposed to be, so will need to do some surching.

[Anonymous]

QUOTE: Originally posted by trainfan1221

It gets more confusing if you throw in the SD60I, which was developed by Conrail with an isolated cab for less noise.

To make it even WORSE, all locos that have the "I" designation ( SD60I, SD75I ) are also wide cab. So what that means is that ALL "I"s are wide cabs, but NOT all wide cabs are "I"s.

[Anonymous]

The power drives AC or DC SD-60M is DC powered and SD-60MAC is AC powered.

[AuTiger19]

Look at the trucks, the SD60M has standard EMD trucks while the SD60MAC has radial trucks like the SD70MAC, SD80MAC, SD90MAC, SD70AC, SD70ACe, SD70M, SD75M, SD75I, SD70, and SD70M-2. I believe those all have radial trucks. The best way to spot an SD60I or SD75I is that the nose of the locomotive has a cut all the way around it. You can really tell in a side view of the locomotive, the cab is not solid, there is a visible separation.

[Anonymous]

Thanks for all the infor on this. So, because I model the BN and would like to have a SD60MAC in demostrator scheme (I saw 1 once on ebay in brass but painted in that scheme for $1600) Way out of my league for a model

Is it safe to get a SD60M and paint it in the SD60MAC scheme?

[caldreamer]

Does anyone know what the starting and continuous tractive efforts were for the SD60's and SD60MAC's?

 

 

[ClinchValleySD40]

kevnbety

QUOTE: Originally posted by trainfan1221

It gets more confusing if you throw in the SD60I, which was developed by Conrail with an isolated cab for less noise.

To make it even WORSE, all locos that have the "I" designation ( SD60I, SD75I ) are also wide cab. So what that means is that ALL "I"s are wide cabs, but NOT all wide cabs are "I"s.

 

I believe the cabs are normal width, it is the nose that is wide.

[BerkshireSteam]

Lets bring some more confusion and accuracy into the post.

All SD60 series (for that matter everything Dash -2 and up) were AC power. A generator created Alternating Current and channeled the electricity through a giant bridge rectifier converting it to Direct Current so the older DC traction motors would operate.

Locomotives from the 60 series and newer with the "AC" moniker means it has AC traction motors. These are much more efficient and better performance. IIRC AC motors can be held in a state of flux between full traction and wheel slip which, ironically enough, creates more traction and thus more power to the rails. Or something like that. I am a little bit surprised to see locos still being produced with DC traction, but then again I have also heard mentioned of a 4-axle variety ES40.

 

As a side note I think should be mentioned, older locos like GP38AC or MP15AC used AC generators (but still DC traction motors), hence the "AC" moniker in the model.