SSPRR Run Room

Playing with Toy Trains

Toy Train Layout Wiring - Basic

Wiring is similar to filling in a dot to dot picture or following a road map.  Join some track.  Hook track to transformer.  Run a train.  As you add more track, wire, and turnouts, stop and Test your work by running a train.
Power Hazard symbol Protect you, your house, trains, wire, and accessories. Transformer internal breakers protect transformers, NOT trains. Shorts or faults can damage your toys and burn down your house. Circuit Protection on the low voltage side of transformers is the same as having breakers in the circuit box for your house wiring.

There are many techniques for wiring a layout.  These have worked for me so that I can play trains instead of messing with the wiring.  The date tags on items in photos are part of my inventory system.


Basic Intermediate Advanced Wire Management Bus Wiring 120V Train Room
Glossary Wire Sizes Switches Load Calculations Soldering Troubleshooting


Here is a dot to dot diagram for a basic loop of track.
(Fuse - See Circuit Protection.)

Basic Drawing

Tug test all connections as you wire.

MTH Trolley Set MTH Trolley w 2 feeds
MTH Ready To Run Set #30-4191 Contents
(Set instructions are very helpful.)
The mark on the transformer knob aligns for correct speed for the trolley.  Note two wires on each terminal.  The red and black wires from banana plugs have spade connectors under the transformer screw plates.  The red and white wires of to the right side would be used for a second track connection on the far side of track.


This "Carpet Central" Layout will work with motorized vehicles.

MTH RealTrax Dogbone 1033 and Plug Strip
Plug transformers into a lighted power strip.  The Lionel postwar 1033 varies track voltage (black lever) and blows the whistle/horn (orange lever).

Combining two set loops of MTH 0-31RealTrax resulted in this "dogbone".  Motorized vehicles run good on it.  Train derailments are more likely with back to back curves shown here.  Six short straights between the inside curved tracks would be a big improvement.


Transformer to Track fused Circuit protection is needed for trains when using larger transformers.  Here's an in line fuse in a holder available from Radio Shack.  (20-Amp Heavy-Duty Inline Fuse Holder for 1¼x¼" Fuses is Catalog #: 270-1217.  Use 3-Amp 250V ACG/SFE-Type 1-1/4x1/4" Glass Fuse (4-Pack) Catalog #: 270-1009)

Track Circuit Protection

The components above can be installed in a project box for frequent use. Auto reset breakers are preferable to fuses. The split terminal strip makes it easier to add track taps if your train slows on the far side away from the first tap. My wire color coding uses white for the track outside rails and black for the center rail.
Extra variable voltage (center rail) taps would be tied in to left side of left terminal strip. The extra common (outside rail) taps would be tied to any terminals on the right terminal strip (all common). The fuse holder can be replaced with a resettable breaker or a PTC resettable fuse.

Option for Additional Track Taps to Modern Track

Alligator clips are crimped and soldered to stranded wire for temporary connections to modern track.

Extra Track Tap Tie Outside Rails Together

Factory Lockon for MTH RealTrax

RealTrax Lockon RealTrax Lockon Bottom

from MTH Ready To Run Set #30-4191 Instructions

MTH Compatibility Chart

MTH M&Ms Trolley 30-4191 with Bumpers

MTH Trolley


Lionel Christmas Trolley 6-11809 with Enhanced Bumpers

Rubber Tape was added to the bumpers so two trolleys running together will bump and reverse each other.  The wheel balancing stick-on weights on the bottom at each end stabilize the trolley.

Lionel Trolley

Lionel Trolley Set 6-11809 027 Track Clips
Track clips 6-2901, sold separately, will keep 027 set
track together when it is not screwed down.

Set track example with track clips and two track connections.  On single loops of track, if trains slows on far side of first connection, add another connection.  If track is screwed to surface, connect to every third section of track so that all track is touching one wired section.

027 Track with Lockons

The above set comes with one lockon.  Added track will require additional wire taps/lockons.  Lockons are temporary track connections.  See correct way to wire lockons below.

Lionel Lockon Correct Wiring
Correct - Bare wires can't touch and cause a short.  These stranded wires are tinned so they are easier to insert into the clip.
Lionel Lockon Incorrect Wiring
Red and black wires are inserted with bare wires toward each other which would be considered "bad practice".


The lockons above show a very good example of two different Color Code conventions.
The AC convention that I use is based on 120V residential and commercial wiring postwar toy train wiring.  My outside rails/commons are tied in with white wire and variable voltage/center rails are black wire.  The AC convention is handy when you get into more than one circuit because there are a lot more colors available. 
The DC convention that is being use with modern toy train wiring applies to low voltage wiring and electronics.  Their outside rails/commons are tied in with black wire and variable voltage/center rails are red wire.
Use the Color Code convention that makes sense to you.

Tips and Cautions for Safety and Ease of Use

Follow the instructions that came with your transformer and track.
For a temporary layout, any electrical wire with good insulation will work. If there's a large or permanent layout in your future, you will want to glance over the Intermediate section.

Safety test your transformer. Unplug the transformer. The electrical cord is safe if you bend the cord and the insulation is free of cracks. Turn voltage knobs to Off. Test the transformer breaker by securing a bare wire with one end to the common terminal and the other end to a voltage output terminal. (The wire should be extension cord size or larger.) Plug cord into electrical outlet. Stand by to pull plug while slowly raising voltage with control knob for the terminal where the wire is attached. If breaker doesn't trip within 2 seconds, Pull Plug and replace or have the breaker replaced. The interior breaker protects the transformer, not the trains.

Before you run modern trains you will want circuit protection for the trains. An engine will Not trip the transformer breaker on larger transformers before engine or plastic truck damage can occur.

Question? Contact the SSPRR COO (Chief Operating Officer) using the email button to the right.  (If email link is absent, please enable JavaScript.) 


Return to 3 Rail O Gauge Toy Trains