Having read the June issue of Model Railroader a couple of times now, I want to comment on one of the thinking pieces in it. The piece is a monthly article written by Andy Sperandeo called "The Operators". In the June issue Andy talks about choosing locomotives for operation and how time and place have a major bearing on those decisions.
The gist of the article was that Andy had selected a specific time period and location for his model railroad - the second half of 1947 in the Cajon Pass area of southern California. That decision reflected his strong personal interest for particular prototype locomotives, especially the 3800 class 2-10-2's, on this section of the Atchison Topeka & Santa Fe. Andy concludes by saying that he has "arrived at a roster (of locomotives) representative of that particular railroad at that particular time and place".
Looking at my own layout, Winmar, I have selected a particular geographic area ("just" north of Albury on the Main South line), although my station name and town are fictional. I have also fictionalised a branch line leaving Winmar and heading east towards the upper reaches of the Murray River - the branch line, of course, being that future extension to the layout once I have a permanent place to house it all.
I am therefore basing much of my operation on Winmar on the real prototype that ran between Sydney and Albury on the Main South line. This allows for 38 class steam locomotives but not 57 class steam locomotives, for example. 57 class locomotives didn't go past Junee on the Main South.
My period of time, however, is much more flexible. I like the early 1960s but I also like the late 1990's as well. And in between, I have a few locos (422 class diesels) and rolling stock (PRX cement wagons, for example) that fit this "middle" period (1970-1990). If I was dedicated and disciplined, I should get rid of these outliers from my collection and concentrate solely on one time period. Having read Andy's article, I understand how such a decision makes decisionmaking on locomotive rosters that much easier (and no doubt, less expensive).
In terms of my collection, however, I just can't make that decision. Sure, in my 1965 period running sessions I will try and keep to the prototype. The 422's and PRY/X cement wagons are banished. Yet, for fun, I will run some of these out-of-period trains for the variety and chance to imagine, albeit imperfectly, that I am back in the late 1970's or early 1980s - but don't get me started on the beginning of the four digit wagon codes!
The outcome is that I have far too many locomotives and too much rolling stock for the time frame and location I am modelling. When I am in my serious operating mode, I can be pretty disciplined as to what I run on the layout and how it all fits together with the prototype.
So maybe Andy is right after all - limiting the locomotive roster to the most favoured time of your favourtite locomotives is the way to go. At least, it's certainly a more inexpensive option and will free up some space in the storage cabinet!