One aspect of era consistency is locomotives. I chose 1953 in part because it was the last year in which the majority of Coast Line power was steam. But the diesels which were present in that year are also part of era consistency. I described in a previous post the SP diesel chronology which is the basis for my modeling (see: http://modelingthesp.blogspot.com/2011/03/modeling-diesel-locomotive-chronology.html).
On the SP as a whole, by 1953 the majority of locomotive miles were already powered by diesels (see graph below, from the 1954 SP Annual Report), but as dieselization progressed in desert and mountain territories, remaining steam migrated to California, where several divisions, including the Coast, continued to use a majority of steam power. Photographic evidence, along with conductor books and other historical material, support this statement.
My own steam locomotive choices are derived from SP booklets of “Locomotive Assignments,” for the Coast Division in 1953 and thereabouts, but further refined with photos of specific locomotives seen multiple times at San Luis Obispo and thus likely candidates not only for mainline freights but for locals and for branchline service. San Luis was the closest division point to my branch line, and its roundhouse was the local servicing facility for locomotives assigned in the area. I will address specific locomotives in a future post.
The choice of 1953 also constrains choices of freight and passenger cars. As others have observed, this can be liberating as much as constraining. Equipment delivered after the end of 1953 can be simply ignored in model form (unless I want to further populate my display case). I will say more about freight car selection in another future post.
Another aspect, I think often neglected, is motor vehicles. Even those who could not name the year or model of any HO scale automobile by looking at it, nevertheless have a generic memory of automobile styles by era. The same goes for highway trucks, though truck models changed less frequently and often less distinctively. I have largely been careful to use only model autos and trucks of 1953 or earlier vintage. The exceptions are in some cases European vehicles (which I chose to have at least a vague resemblance to period American cars), and are always placed in background locations where they will hopefully attract less attention. I expect to eventually replace all of them.
A further point to mention about cars is license plates. Yes, all automobiles had license plates, front and back, and of course they should be present on models. For any state or era, there are extensive and detailed Internet resources to provide both history and images of actual license plates, greatly simplifying the task of accurate HO scale license plates. For California, for example, the Wikipedia entry is extremely complete and helpful (see: http://en.wikipedia.org/wiki/Vehicle_registration_plates_of_California). There is also a site offering reproduction plates for many states and many years, available at: http://www.licenseplates.tv/index, and this site has good plate images to view.
The bottom line for California in 1953 is that the license plate was black with yellow numbers; actually it was the 1951 plate, with a lower right corner tab of stamped metal with the number “53” on it, covering up the “51” part of the year on the original stamped plate. All older plates had been replaced in 1951, so regardless of vehicle age, it got a 1951 plate in that year. The exceptions in 1953 were new plates, which did have the 1953 date stamped in. Thus the plates on any vehicle would have looked like one of these two examples:
Accordingly, this is the format for my HO scale plates. Like so many things in modeling, you may think adding plates to an auto or two now, and a few later on, can be a progressive project, but once your eye starts to notice the plates, you find you just have to go ahead and make plates for all of the cars on the layout.
There are of course other era-consistency issues to recognize. Company names and emblems on buildings or billboards should neither post-date your chosen era, nor be too old (yes, old posters sometimes survived, and if so should be in decrepit condition, but billboards were revenue-producers and were updated). In fact, such advertising is an opportunity to identify your modeled year, with things like ads for new cars, or for political campaigns. For example, an “I Like Ike” ad on a 1952 layout would immediately bring to mind the presidential campaign of that year. But for 1953, as on my layout, such a sign, if included, would be faded and dirty.