Tuesday, July 01, 2008

Modules and Sections and Dominoes, Oh My!

This is going to be one of those model railroad layout design screeds that makes me feel slightly better but has no discernible impact on the hobby whatsoever. Ready? Here goes: the terms in the title above are not synonyms!!

Sections are just what the name implies. They are chunks of layout. They’ve been built separately for easier transportation, construction, etc. They often have legs so that they may stand alone, but could be suspended from a wall or between other sections. Sections may be flat-topped or open grid or some combination or variation. (Typically, they are not L-girder for obvious reasons.) Sections may be any shape or size. A sectional layout typically is built to fit together in one particular configuration – the sections are not interchangeable without some rework or addition of new bridging sections for a new space.

Modules are sections of layout that have been designed to a standard like NTRAK, Free‑Mo, or (many) others so that they may be interchangeably combined with other modules to form a layout. Some of these standards are national or international in scope, others defined by a single club, informal group, or individual. These standards define the track and electrical connections for mating ends. In some cases, the size and/or aspect ratio of modules are specified, but this is not universal. Adjoining modules may be built by the same or different people … but the interface between them is standardized. That’s what makes them modules. Sometimes people choose to build multi-module sets where the intermediate interfaces may not be built to the standard, but the ends are, to permit connections with modules built by others. The key is the standard interface at the ends. Ergo, all modules are sections, but not all sections are modules.

The term “domino” was borrowed by David Barrow to describe 2’X4’ flat-topped layout sections with legs. See, they look like a domino – with the flat top and 2X4 aspect ratio – just like a domino, get it? Thus, all dominoes are sections, but not all sections are dominoes. (By the way, dominoes may be an OK way to build some types of layout, but they are a really bad way to design a layout, in my humble opinion. But that’s a rant for another day.)

["Doorminoes", by the way, are a pretty cool idea: layouts or layout sections built on hollow core doors. Doorminoes have been used and popularized by Dave Clemens, among others.]

Let’s review:
- Sections are chunks of layout; size, shape, and track and electrical interfaces between sections are not standardized
- Modules are sections built to a standardized defined trackwork and electrical interface for interchangeability
- Domino is a term to describe a specific aspect ratio flat-topped section

OK, got it?

Hey, I do feel a little better.