UP locomotive numbering scheme

What is the logic behind UP's numering scheme?

On the SP, the 1000-2000 series were switchers, 3000s used to be passenger locomotives but later were mostly GP-9s, 4000-5000s were low horsepower road units, 6000-9000 were medium-high horsepower units. But I can't seem to figure out UP's system, except that 9000 series numbers are locomotives that are about to be retired, and UPY locomotives are yard switchers (but not all yard switchers are lettered UPY).

wigwagfan wrote:What is the logic behind UP's numering scheme?

On the SP, the 1000-2000 series were switchers, 3000s used to be passenger locomotives but later were mostly GP-9s, 4000-5000s were low horsepower road units, 6000-9000 were medium-high horsepower units. But I can't seem to figure out UP's system, except that 9000 series numbers are locomotives that are about to be retired, and UPY locomotives are yard switchers (but not all yard switchers are lettered UPY).

UP's seems to be....

1-999 are medium HP 4-axles (GP38-2s, GP40s, B23-7s)

Pretty much the same for up to about the 2600 series

Then it's SD40-2 country, including SD40M-2s, all the way up to the 3900s

3900's-5300's are SD70Ms

5400 (built soon) to 7999- with few exceptions, are GE coal hauler AC units

Some of these exceptions are former SD40-2Bs with cabs put back in, and ex-SP B23-7s

8000-8200, 8500 are SD9043MACs and SD90MACs

Rest of 8500s through 8800s seem to be old SP tunnel motors

9000-9834 are medium-high HP GE's (Dash 8s and 9s)

From 9835 and up, junk that's being run into the ground

CNW_4404_Lover wrote:

wigwagfan wrote:What is the logic behind UP's numering scheme?

UP's seems to be....

1-999 are medium HP 4-axles (GP38-2s, GP40s, B23-7s)

Up to UP 2090 for four axle units. These include GP50's GP60's, and GP40-2's also.

Pretty much the same for up to about the 2600 series

UP 2100 to 22xx is SD60's.

Then it's SD40-2 country, including SD40M-2s, all the way up to the 3900s

Junkers and leased units UP 26xx to UP 2940, former CNW SD40-2's are 2952 to 3098. The logic here is that the former CNW units are equipped with ATC/CSS, so keeping them distict helps on assignment. (there is a gap in that)

3900's-5300's are SD70Ms

3780 to 5230 are SD70's

5400 (built soon) to 7999- with few exceptions, are GE coal hauler AC units

UP 5354 to UP 7400 C44AC's.

Some of these exceptions are former SD40-2Bs with cabs put back in, and ex-SP B23-7s

UP 7700 to 7999 are as he states, B23-7's and junkers.

8000-8200, 8500 are SD9043MACs and SD90MACs

UP 8000 to UP 8308 are SD90/43's. UP 8309 to 8423 will be the SD70ACe's. UP 8500 to 8561 SD90's.

Rest of 8500s through 8800s seem to be old SP tunnel motors

Yep, hard to find in some places.

9000-9834 are medium-high HP GE's (Dash 8s and 9s)

From 9835 and up, junk that's being run into the ground

Most all UPY's will be found in yard service. Some poor saps on locals however, get GP15's as road power, what a pity. In the northern region, the smaller terminals will get GP38-2's or GP60's for yard service as well as locals. On the branch lines, it is not uncommon to see four GP's pulling a grain train. Flexibility in loco assignment.

Mine were just rough estimates...sorry, shoulda mentioned that

And I also wasn't thinking when I put the AC44 stuff......