The Model Railway Handbook

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Six decisions, one shopping list, and a train running by the weekend.

You do not need a plan for the finished railway. You need enough decided that the money you spend this month is still useful next year. These are the six choices that lock things in, in the order they actually bite.

The six decisions

Make these in order. Each one narrows the next, and only the first two are expensive to change later.

1

Scale — how big is a person?

Everything else is downstream of this. HO (1:87) in North America and Europe, or OO (1:76) in Britain, is the default for a reason: the widest choice of models, the most forgiving size for adult fingers, and enough mass that trains run smoothly. Choose N (1:160 / 1:148) if space is tight and your eyesight is good. Choose O or G if you want to see rivets, and have a garage or a garden.

The full scale comparison →

2

Space — and, more importantly, its shape

Measure the actual space, then subtract the aisle. A layout you cannot walk round is a layout you cannot reach into, and everything on a railway eventually needs reaching: a derailed wagon, a dead frog, a tree that fell over.

  • Reach limit: 75 cm (30 in) from the edge if you are standing. Any deeper and you will be leaning on your scenery.
  • Aisle: 60 cm (24 in) absolute minimum, 75 cm if two people will ever operate together.
  • Height: 100–130 cm puts the trains near eye level, which flatters everything you build and hides the fact that the backdrop is 40 cm away.

A shelf 30 cm deep along one wall beats an island in the middle of the room in almost every domestic situation.

3

Place and period — the two-sentence brief

Write one sentence: “A single-track branch in the Welsh borders, 1962, the last year of steam.” or “An industrial switching district in New Jersey, 1978, Conrail blue everywhere.” That sentence decides which locomotives, which wagons, which buildings, which colour the signals are, and — most usefully — what you do not buy.

Why this saves money

The single most common cause of a stalled collection is a shelf of unrelated models bought because they were on offer. A brief turns browsing into shopping.

You are allowed to break the brief. Knowing you are breaking it is the point.

4

DC or DCC

DC: one controller varies the voltage on the rails; every locomotive on that wiring section obeys. Cheap, simple, and it means dividing your track into electrically isolated blocks if you want two trains moving.

DCC: the rails carry a constant digital signal; each locomotive has a decoder with its own address, so it responds only to commands addressed to it. More expensive up front, far less wiring, and it is what almost everything is sold ready for.

If you are building anything with more than one locomotive, start DCC and skip the rewire — how DCC works →

5

A track system, and stick to it

Track brands differ in rail height, sleeper spacing, geometry and how their turnouts handle the frog. Mixing them is possible but tedious. Pick one family now:

  • Peco (code 100 / code 75 / code 83) — the British default, superb turnouts, sold everywhere.
  • Atlas (code 100 / code 83) — the North American default, cheap and forgiving.
  • Kato Unitrack / Tomix — track with the roadbed moulded on. Clips together, comes apart, absurdly reliable. Perfect for a temporary or portable layout.
  • Micro Engineering, Fast Tracks jigs — for when you have opinions about sleeper spacing.

Whatever you choose, buy flexible track rather than short curved sections as soon as you can. It is cheaper per metre and lets you use a radius of your own choosing.

6

What the railway is for

Three honest answers, all fine:

Watching

Continuous run, long trains, scenery you sit and look at. Wants: an oval or a folded loop, generous curves, a view block so the same train reappears as if from somewhere else.

Working

Shunting puzzles, deliveries, a timetable. Wants: turnouts, spurs, a run-round, and almost no continuous run at all. Fits a shelf.

Making

The railway is a stage for modelling: kit-building, weathering, structures. Wants: small track plan, big scenic ambition, good lighting.

How much space each scale really needs

The binding constraint is not length, it is the width needed to turn a train round. A continuous run needs two half-turns, so the board must be at least twice the minimum radius plus a margin. These are the practical minima — the radii at which ordinary models behave.

ZNHO / OO SOG 19 in / 48 cm 26 in / 66 cm 42 in / 107 cm 54 in / 137 cm 68 in / 173 cm 100 in / 254 cm width of a hollow-core door (32 in / 80 cm) — the classic small-layout baseboard Board width needed for a 180° turn at each scale's practical minimum radius, plus 3 in of scenic margin.
In HO you can just get a continuous run on a door. In N you can get a railway. In O you need a room, and in G you need weather.
The shelf exemption

All of the above is about turning round. If trains arrive from off-stage and leave the same way — a shelf switching layout with a cassette at each end — the width constraint vanishes and HO fits comfortably on 30 cm of depth, O on 45 cm.

Three ways in

All three end in the same place. They differ in what you learn first and what you waste.

Lowest risk

Buy a train set

A box with a locomotive, three or four wagons, an oval of sectional track and a controller, for $120–250.

You get: a running train in an hour, and a locomotive worth keeping.

You waste: the track. Set curves are 15–18 in radius and the rail is chunky. Treat it as a test track, not a foundation.

Best value

Buy the parts separately

One good locomotive, six wagons, a length of flex track, four turnouts, a DCC starter system. $400–600.

You get: everything survives into the real layout.

You waste: two evenings of research, and you will make one wrong choice. Everyone does.

Cheapest

Buy someone else's collection

Club sales, estate sales, swap meets. A box of 1990s HO for the price of one new wagon.

You get: volume, and permission to experiment — this is the stock you learn to weather on.

You waste: time. Expect horn-hook couplers, plastic wheels and at least one motor that has died of dried grease.

The first shopping list

For a 6 ft × 3 ft HO or OO layout. Buy the tools first — they are what turn a box of parts into a railway, and they last forever.

BuyWhich oneWhy it matters
Track gaugeNMRA standards gauge, or a NEM equivalent A slotted piece of steel that tells you whether track, wheels and couplers are within tolerance. It will find faults you would otherwise chase for months.
Rail nippersXuron 2175 or equivalent Cuts rail flush without crushing it. Side cutters from a toolbox will mangle the railhead and cause derailments at every joint.
Soldering iron25–40 W, chisel tip, plus 60/40 or lead-free rosin-core solder Feeders soldered to the rail are the single biggest reliability upgrade on any layout.
MultimeterAnything with a continuity beep Answers “is there power here?” in two seconds instead of twenty minutes.
Flex track6–8 lengths, code 83 (HO) or code 75 (OO) Smooth curves of any radius, fewer joints, and it looks right. Code 100 is fine if you have older stock with deep flanges.
Turnouts4 × #6 (or Peco medium radius) The #4 turnouts in most sets look toy-like and restrict what can pass. #6 is the sweet spot for everything but the tightest shelf.
Cork or foam roadbedA roll, plus a tube of latex caulk Raises the track, gives it a shoulder to ballast against, and deadens the drumming noise from the baseboard.
BaseboardA hollow-core door, or 9 mm ply on a 50 × 25 mm frame, topped with 25 mm extruded foam Flat and rigid. Foam on top lets you carve down for water and push pins in anywhere.
ControlA DCC starter set (NCE Power Cab, Digitrax Zephyr, Z21 start, Roco/Hornby elite) 2 A is plenty for a small layout. Buy one that lets you add a bigger booster later.
Wire16–14 AWG for the bus, 22–24 AWG for feeders A fat bus under the board with thin droppers to each length of rail. Rail joiners are mechanical, not electrical.

From empty table to first train

Fourteen steps, in order. Tick them off — the list remembers between visits. Nothing here needs a skill you don't already have; several steps are mostly waiting for glue.

Five mistakes almost everyone makes once

Including the person who wrote this page.

Ballasting before the track is proven

Ballast glues everything solid, including the fault. Prove the track over days of running first. If you must fix something later, isopropyl alcohol softens dried PVA.

Curves that are as tight as the packet allows

“Minimum radius” on the box means the tightest curve a short wheelbase model will negotiate without falling off — not the radius at which anything looks or runs well. Add 25% and your problems mostly disappear.

Relying on rail joiners for electricity

They are springs made of nickel silver; they oxidise, they loosen, and they get pushed apart by expansion. Feeders every metre at worst, every length at best.

An S-bend with no straight between the curves

A reverse curve throws a long vehicle one way then instantly the other, and the couplers pull it off the rails. Leave at least one vehicle length of straight between opposing curves.

Building a plan that is all main line

A loop is fun for about three weeks. Two turnouts and a siding is fun for years, because it gives you something to do.

Buying scenery materials before track materials

Static grass is more fun than solder. The railway still needs solder.