The hard question is what's just enough, "lagom" in Swedish.

The answer is 42

Why a model railway?

I want something different to my work. I want to create something physical with my hands, mostly during winter time. Summer is garden time. No pressure of being ready in time, or taking care of everyday chores.

Back to planning

I learned the hard way that space, time and cost are limitations you need to take care of, even in the city planning of a fictional town.

The most critical factor is space, as the maximum size I can accommodate is of the size of a plywood board, 240 x 120 cm or 4 by 8 feet.

Remember technical debt?

I don't want to pay much for new stuff, or scrap what I already have bought. Worst case scenario, there is a huge second-hand market were I can sell without to much loss.

In hindsight, I should probably gone for a smaller scale, but this is something very hard to change halfway though a layout. The same issue with choice of two-rail and three-rail system. Once selected, difficult to do anything about.

If you begin with Märklin H0, you are stuck with the german brand. With 2-rail systems, not so much.

Measure twice, cut once

Time is limited, so I need to avoid to build too much that needs to rebuild later. Re-build also add cost.

Digital chores

An additional complexity is digitalization of the model railroad. You have many options to chose from, and they impact your layout and cost. Is it also dependent on your choice of brand. Not easy to understand how it works in practice for me, even if I have a background with PLC and SCADA-systems.

Is this enough?

Often no.

You should decide what era, timeframe you want your layout to have. Railroads have been around for 150 years and trains and track layout have changed during this time. To understand this, we need to step back and think about the purpose with railroads. E.g. transport of goods and passengers between different locations, often with stations and yards.

If you prioritize landscape before running trains like Dawn with her Ladykillers layout this is even more important, as both landscape and rolling stock differs between countries. Your layout can also be smaller compared to if you prioritize running trains that often need more space. The difference choices we do impact the other decisions.

We also need to assure that what we want on the model railroad exists in the scale we choose, where H0 have most options and smaller scale less. Otherwise, we must create our own bespoke models.

Just enough high-level

At an early stage, before buying anything expensive, you need to take descions about:

Size
Scale
2-way or 3-rail system
Analog or digital train control
Timeperiod, e.g. era.
Prio of building landscape or running trains, or both.
Budget, or more time.

To take these descisions, you need a lot of knowledge about the subjects of railways and model railroading. Perhaps you need to try different things, buy used stuff or borrow from friends.

The positive thing with these seven design decisions is that you can go very agile after answering them. Schrittwise or step by step as I will discuss later.

You can use the same approach for your large program. You need several of high-level decisions for your design, then you can be more agile.

We architect often talk about city plans, but we seldom give examples. I’m trying to explain the architecture view in another perspective with this serie of articles.

Enjoy.

Disruptive architecture