Locomotive models are too confusing

[CSSHEGEWISCH]

cefinkjr

ATSF seems to have always used locomotive numbers for steam locomotive types. Did they even have an alphanumeric class system?

ATSF used the number of the lead locomotive of that design as the class type, such as 3829, 5000, 5001 and 5011 as classes of 2-10-4's.  This system continued well into the diesel era, which must have been quite confusing with various classed of F3's and F7's.

[BaltACD]

The thing to remember about any system of identification - "It made sense to the people that originated it at the time they originated it".  Times change and what made sense 50 years ago, may not make sense today.  What makes sense today most likely won't make sense a generation or two into the future.

[Overmod]

You want confusion in a system of identifying locomotives by class -- it's hard to beat this railroad's approach.  You'd pretty well have to go to some countries in Europe to find anything else with complicated fractions in the class designation...

[cefinkjr]

Overmod

You want confusion in a system of identifying locomotives by class -- it's hard to beat this railroad's approach.  You'd pretty well have to go to some countries in Europe to find anything else with complicated fractions in the class designation...

My unprofessional diagnosis is that this class designation was dreamed up by some seriously OCD engineers.

And isn't the U.P. on this cab a bit unnecessary?

[Kyle]

It makes sense if you really research it, and it is explained in depth. However it is confusing if you don't understand it. I still don't completely understand everything. Yes, the GP38s, GP40s, SD40s, GP38-2s, GP40-2s, SD40-2s, etc where easy to understand without that much explaintion. -2 makes sense for an upgraded versions (now they have -3s, talk about ugly).
Basically the SD70s came along, then they built SD80s and SD90s before going back the the SD70 and adding letters like M on the end. That is where it gets really confusing. I am still not following all of these variants, except the SD70ACe (Standard Duty Model 70, AC traction motors, enhanced).

[CSSHEGEWISCH]

Overmod

You want confusion in a system of identifying locomotives by class -- it's hard to beat this railroad's approach.  You'd pretty well have to go to some countries in Europe to find anything else with complicated fractions in the class designation...

I don't think that the line on the side of UP 4017 is exactly a class designation since UP did have an alphanumeric class designation for its steam locomotives.  It looks more like some basic specs of wheel arrangement and cylinder dimensions.  I believe that Southern had something similar on the sides of its locomotive cabs.