GP vs SD

[ironhorseman]

What's the (visual) difference between a GP and an SD? I have a hunch it might be the number of axles per truck. 2 for GP and 3 for SD? Am I on the right track or am I mixed up?

[ironhorseman]

What's the (visual) difference between a GP and an SD? I have a hunch it might be the number of axles per truck. 2 for GP and 3 for SD? Am I on the right track or am I mixed up?

[eolafan]

Ironhorseman, you are essentially right on with your statement. An SD will have six axles and a GP four. The SD will generally be quite a bit longer in the frame but not necessarilly in the hood area (i.e. a GP40 and an SD40 will be about the same length of hood but the SD will be much longer overall (sometimes you can best see the difference in the length of the front and back "porches" on the older SD's such as the SD40-2, etc.). Jim

[eolafan]

Ironhorseman, you are essentially right on with your statement. An SD will have six axles and a GP four. The SD will generally be quite a bit longer in the frame but not necessarilly in the hood area (i.e. a GP40 and an SD40 will be about the same length of hood but the SD will be much longer overall (sometimes you can best see the difference in the length of the front and back "porches" on the older SD's such as the SD40-2, etc.). Jim

[CShaveRR]

You got it in one!

Of course, you'll find that SDs have longer carbodies, larger dynamic brake areas, etc., all due to the presence of the two extra axles.

[CShaveRR]

You got it in one!

Of course, you'll find that SDs have longer carbodies, larger dynamic brake areas, etc., all due to the presence of the two extra axles.

[Anonymous]

There hasn't been a purchase of new 4-axle power in what about ten years now (since the GE Dash8-40B and the EMD GP60 models)? I am still holding out hope that someone, perhaps NS will purchase the new GP15 and GP20 that they have recently been testing. These models have yet to find a permanent home on any railroad. It would be nice to see some new 4-axle power polishing the rails again.

[Anonymous]

There hasn't been a purchase of new 4-axle power in what about ten years now (since the GE Dash8-40B and the EMD GP60 models)? I am still holding out hope that someone, perhaps NS will purchase the new GP15 and GP20 that they have recently been testing. These models have yet to find a permanent home on any railroad. It would be nice to see some new 4-axle power polishing the rails again.

[eolafan]

appst03 makes a good point about four axle power, but with so big a percentage of trains today being very long and very heavy and traveling very fast, six axle power makes the most sense. I too long to see the successor to the GP60M (which somehow brings back memories of the F9 to me...hmmmm).

[eolafan]

appst03 makes a good point about four axle power, but with so big a percentage of trains today being very long and very heavy and traveling very fast, six axle power makes the most sense. I too long to see the successor to the GP60M (which somehow brings back memories of the F9 to me...hmmmm).

[CShaveRR]

It was just in the news yesterday that UP is going to lease ten of those GP20Ds, and use them in the Houston area. It's a start...

[CShaveRR]

It was just in the news yesterday that UP is going to lease ten of those GP20Ds, and use them in the Houston area. It's a start...

[Anonymous]

I get to watch the GTW (Grand Trunk Western) which is a subsidiary of CN. I live by the Andersonville siding on the Holly Subdivision. The GTW had a lot of GP38-2 locos and still has quite a few in service. Just about all the trains originating on the Holly sub have them as power. I think GTW's motto for the GP units is that "Old GP's never die, they just get rebuilt". If I am not mistaken the GP38-2's in service today have been rebuilt twice. We had a head-on collision right behind my house in November of 2001. Both trains were local to the Holly sub, so all the power were GTW units. One train had two GP38-2s and the other had a GP38-2 and an SD40-2. Unfortunately, the GP38-2 that was paired with the SD40-2 was almost completely destroyed and had to be scrapped. I watched it get cut apart, and the only things salvaged were the truck/motor assemblies, the short hood, and a few pieces of the long hood. They were going to be used as spare parts for the rest of the roster. It's always a shame to lose a veteran 4-axle. Just not many left.

[Anonymous]

I get to watch the GTW (Grand Trunk Western) which is a subsidiary of CN. I live by the Andersonville siding on the Holly Subdivision. The GTW had a lot of GP38-2 locos and still has quite a few in service. Just about all the trains originating on the Holly sub have them as power. I think GTW's motto for the GP units is that "Old GP's never die, they just get rebuilt". If I am not mistaken the GP38-2's in service today have been rebuilt twice. We had a head-on collision right behind my house in November of 2001. Both trains were local to the Holly sub, so all the power were GTW units. One train had two GP38-2s and the other had a GP38-2 and an SD40-2. Unfortunately, the GP38-2 that was paired with the SD40-2 was almost completely destroyed and had to be scrapped. I watched it get cut apart, and the only things salvaged were the truck/motor assemblies, the short hood, and a few pieces of the long hood. They were going to be used as spare parts for the rest of the roster. It's always a shame to lose a veteran 4-axle. Just not many left.

[Anonymous]

Emd calls the GP, General Purpose and the SD is called Super Duty.

[Anonymous]

Emd calls the GP, General Purpose and the SD is called Super Duty.

[billchown]

I saw a GP15 today; UP at Albina, and assumed it was an old model (numbers seem to just keep going up!).
Where is areference to the different types; I'm new to these type of power, having only paid attention to much older stuff previously?

[billchown]

I saw a GP15 today; UP at Albina, and assumed it was an old model (numbers seem to just keep going up!).
Where is areference to the different types; I'm new to these type of power, having only paid attention to much older stuff previously?

[f14aplusfl]

Well with the SD's they also get greater traction. I remeber reading an article in Trains a long time ago about the Montana Rail Link. The GP's are more prone to "slip" in the mountainous areas with the long and heavy trains. Here in Florida, I get to watch Florida East Coast Railway GP-40s and 38s, not to mention the occasional GP9! The GPs can be seen powering sand (there is a number of them going North for cement), intermodal, through, and local trains. They use any locomotive for these tasks but I've never seen a GP9 on an intermodal hotshot train's locomotive consist. Also I've seen a few SD-40s, but I'm not to sure if they're leased or bought from the Union Pacific RR (the UP marking are just painted over). But the majority of trains often have one or more GPs in front. Florida is pretty flat so they really don't need the extra traction the SDs offer. So GPs are found here for the time being.... though I've seen a few NS six axle (was't able to ID them) on the front of a few trains on the FEC line through town. Anybody know what's the deal with that?

[f14aplusfl]

Well with the SD's they also get greater traction. I remeber reading an article in Trains a long time ago about the Montana Rail Link. The GP's are more prone to "slip" in the mountainous areas with the long and heavy trains. Here in Florida, I get to watch Florida East Coast Railway GP-40s and 38s, not to mention the occasional GP9! The GPs can be seen powering sand (there is a number of them going North for cement), intermodal, through, and local trains. They use any locomotive for these tasks but I've never seen a GP9 on an intermodal hotshot train's locomotive consist. Also I've seen a few SD-40s, but I'm not to sure if they're leased or bought from the Union Pacific RR (the UP marking are just painted over). But the majority of trains often have one or more GPs in front. Florida is pretty flat so they really don't need the extra traction the SDs offer. So GPs are found here for the time being.... though I've seen a few NS six axle (was't able to ID them) on the front of a few trains on the FEC line through town. Anybody know what's the deal with that?

[leewal]

I thought SD meant "special duty" not "super duty"

[leewal]

I thought SD meant "special duty" not "super duty"

[swknox]

I have to agree the SD's get more traction and power to the rails which results in less slip. I don't know of any GP's that have 6 axels only 4 and the SD's have 6 axels. I live in Delaware just outside the town of Harrington where Norfolk Southern has its main terminal here on the Delmarva Branch. They use anything and everything here. I seen GP38's, GP40's, with short and high hoods (GP40 only) and modern SD's from EMD and General Electric. If anybody want to see some 4 axel Alcos in action then you need to visit see the Maryland & Delaware Railroad which also serves the shore. If anybody want a neat look into operations here on the shore than visit this website www.trainweb.org/peninsularailfan/index.html

[swknox]

I have to agree the SD's get more traction and power to the rails which results in less slip. I don't know of any GP's that have 6 axels only 4 and the SD's have 6 axels. I live in Delaware just outside the town of Harrington where Norfolk Southern has its main terminal here on the Delmarva Branch. They use anything and everything here. I seen GP38's, GP40's, with short and high hoods (GP40 only) and modern SD's from EMD and General Electric. If anybody want to see some 4 axel Alcos in action then you need to visit see the Maryland & Delaware Railroad which also serves the shore. If anybody want a neat look into operations here on the shore than visit this website www.trainweb.org/peninsularailfan/index.html

[Anonymous]

ALL GP's are 4 axle units. GP-9, GP-38-2, GP-60m, etc...
ALL SD's are 6 axle units SD-9, SD-40-2, SD79MAC, etc...
ALL F's are 4 axle units F-7, F-9, etc...
ALL E's are 6 axle units E-8's, etc....
ALL SW's and MP's are 4 axle units. SW-7, SW-1500, MP-1500DC
GP's are "General Purpose", SD's are "Special Duty"


When it comes to GE's....
Anything with a "B" in the model number is 4 axle U23B, B23-7, Dash8-40B, etc...
Anything with a "C" is a 6 axle. U30C, C36-7, Dash9-44C, etc...

As has been said by others....the carbody on the six-axle units are generally longer and some of the equipment features located in different places or are shaped differently or are larger than their counter parts.

[Anonymous]

ALL GP's are 4 axle units. GP-9, GP-38-2, GP-60m, etc...
ALL SD's are 6 axle units SD-9, SD-40-2, SD79MAC, etc...
ALL F's are 4 axle units F-7, F-9, etc...
ALL E's are 6 axle units E-8's, etc....
ALL SW's and MP's are 4 axle units. SW-7, SW-1500, MP-1500DC
GP's are "General Purpose", SD's are "Special Duty"


When it comes to GE's....
Anything with a "B" in the model number is 4 axle U23B, B23-7, Dash8-40B, etc...
Anything with a "C" is a 6 axle. U30C, C36-7, Dash9-44C, etc...

As has been said by others....the carbody on the six-axle units are generally longer and some of the equipment features located in different places or are shaped differently or are larger than their counter parts.

[Anonymous]

The SD79MAC in my above post was a typo, was supposed to be SD70MAC. I do not know of a 79 model series.

[Anonymous]

The SD79MAC in my above post was a typo, was supposed to be SD70MAC. I do not know of a 79 model series.

[Anonymous]

for leewal: you are correct SD does mean Special Duty, ALTHOUGH now-a-days you probally could call SDs Super Duties, because they (and other 6 axle units) handle virtually every mainline, regional, and some short line road jobs.
for billchown: the GP15/GP15-1 is an older model, EMD said if the railroads gave them their old GP7s and 9s they would remanufacture them into GP15-1s, not many RRs took this offer though, as only around 300-330 units were produced, the EMD GP15D however is a new model, it uses a CAT prime mover (the work is sub-contracted to Boise Rail (formerly MK)), and last but not least, although not GP15Ds or GP20Ds, the PTRA of Houston owns 24 MK1500Ds which burn diesel fuel, and are essentially the predecessors of GP15Ds and GP20Ds. Wow, I'm gonna take a nap now!

[Anonymous]

for leewal: you are correct SD does mean Special Duty, ALTHOUGH now-a-days you probally could call SDs Super Duties, because they (and other 6 axle units) handle virtually every mainline, regional, and some short line road jobs.
for billchown: the GP15/GP15-1 is an older model, EMD said if the railroads gave them their old GP7s and 9s they would remanufacture them into GP15-1s, not many RRs took this offer though, as only around 300-330 units were produced, the EMD GP15D however is a new model, it uses a CAT prime mover (the work is sub-contracted to Boise Rail (formerly MK)), and last but not least, although not GP15Ds or GP20Ds, the PTRA of Houston owns 24 MK1500Ds which burn diesel fuel, and are essentially the predecessors of GP15Ds and GP20Ds. Wow, I'm gonna take a nap now!