One of the common questions people have when building a train layout is how long can their train tracks be? Unfortunately, the answer is quite complicated, and there is no definite answer because an extremely long and complex track can cause voltage drops and short circuits. Thus, I decided to provide some guidance to help you correctly wire your tracks.
You can make your train tracks as long as you want. In fact, the longest model train track, according to the Guinness Book of World Records, is 15,400 m or 50,525 ft. However, long and complicated tracks require meticulous wiring to prevent short circuits and voltage drops.
This post will not only discuss how long train tracks should be before adding another wiring, but we will also talk about some common complications on larger layouts and widely accepted rules to prevent these complications.
How Long Should Train Tracks Be Before Adding a New Wiring
As a general rule, each wiring can accommodate 5 to 10 meters of tracks (16.5 to 33 feet). Going further than 10 meters can cause voltage drops since the tracks have some resistance which converts electricity to heat. Voltage drops make the electricity on the tracks inconsistent which affects the speed of the trains.
Some people think that you can add as many tracks as you want on your model train, and it will still run smoothly.
The truth is, it is more complicated than that.
Large layouts usually require more than 1 wiring to power the entire layout equally.
This is because voltage drops are common to large train layouts.
Thus, telling how long train tracks can be would be complicated since, theoretically, you can add as long as you want.
As a matter of fact, the Guinness Book of World Records for the longest model train layout is an HO gauge train in Germany named Miniatur Wunderland.
This massive train layout is 15,400m (50,525 ft). To give some context, Mount Everest is 8,848.86 meters high. The layout is almost twice the height of Mount Everest.
You can also do this, provided that you know how to wire your layout correctly.
You should know when to add more wiring, especially on complicated tracks such as these.
But when should we add more wiring? Well, that’s our topic for the next section.
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What Are the Things To Take Note of Before Making a Large Track
When making a large track, take note of voltage drops and short circuits. As long as you can prevent these, you can make your layout as big as possible.
Voltage drops prevent trains from moving smoothly, while short circuits can burn the wiring and motor.
But what are these, and how can we prevent them? Let’s discuss them individually.
1. Voltage Drop
As the name implies, voltage drops are when the voltage is reduced on certain parts of the track.
But what are volts and their relationship with operating your model train?
Generally speaking, the more voltage you give to your model trains, the faster it will be.
The knob you will usually see on DC-controlled model trains is a knob for adjusting the voltage.
A typical DC-controlled HO train runs from 0 to 12 volts. The motor runs at full speed when it reaches 12 volts.
However, the maximum voltage to get the full speed depends on the train scale and controls.
Recommended Read: I made a complete table summary on the train model scales and what voltage they run on. I also discussed in that post the factors that can affect these numbers, such as train scale and controls. If you’re interested, please check this post: What Voltage Do Model Trains Run On?
Now, the voltage drop is when the voltage isn’t the same for the whole track. Generally, having a 0.5 voltage drop is common and negligible. However, a 1 voltage drop can significantly affect how your train runs.
If you notice your train gets slower on specific parts of the track, that is most likely a voltage drop.
However, it isn’t true that voltage drops cause all slowdowns. The first thing to check is other factors such as inclines, turnouts, or unexpected blocks along the rail.
If these aren’t the cause, then we might consider voltage drop.
Why? Because voltage drops are uncommon and only happen on large layouts.
But what causes voltage drop?
Voltage happens because while the model train tracks are conductors of electricity, they also have some resistance. However, this resistance is often negligible except if the track is extremely long.
Basically, resistance converts electricity to heat. However, this resistance is too small to cause some trouble on most layouts.
However, large layouts make this resistance apparent and cause voltage drops.
Basically, the longer the rails, the more voltage drop.
But why is this uncommon? Simply because most train layouts won’t reach tracks that are long enough to cause these drops.
But what causes voltage drops on model trains?
Here are the factors that affect voltage drop on model trains:
- Length of Wiring/Track
- Quality of Wiring/Track
- Amount of Voltage Given To The Track
One of the most important here is the length of the track. As I previously discussed, the longer the track, the higher the resistance, which causes voltage drops.
Thus, generally speaking, long tracks require more wiring to prevent these drops. How long? Every 5 to 10 meters of track requires a new set of wirings to avoid voltage drops.
But what tracks require 5 or 10 meters? Well, that’s why track quality matters.
The quality of the wiring or tracks matters when it comes to voltage drop. Basically, the thicker the tracks, the better it is in handling voltage drops.
That’s why cheap tracks can only handle 5 meters of length before getting voltage drops, and high-quality tracks can be as long as 10 meters without having one.
Lastly, the amount of electricity you give to the circuit.
The more electricity you give, the more energy the tracks will convert to heat. That’s why some experiments on breaking the record for the fastest model trains caused the track’s wiring, motor, and train wheels to burn or spark.
That’s why on some attempts to break the fastest model trains, when they started to give 40 volts, you can see a spark on the rails, which eventually burns the train motor and wheels. This is an example of the track’s resistance to using excess electricity to make heat.
While the voltage drop isn’t apparent on these attempts since the train is running extremely fast, these experiments show the heat the tracks can emit from voltage drops.
Recommended Read: Did you know that the fastest model train reached the scale speed of 850mph? To find out about this experiment, please check this post: How fast can model trains run?
Combining all of this information, we can say that you should add an additional wiring for every 5 to 10 meters of track.
That’s why it is a general rule for train modelers to add an additional wiring every 5 meters or 16.5 feet of track.
That way, we prevent voltage drops.
However, there are times when we have to add more wirings even if the track isn’t as long as 5 meters. That’s what we will talk about in the next section about short circuits.
2. Short Circuits
On model trains, a short circuit happens when positive and negative charges on the rails combine. This causes excess heat to break the train’s internal circuit and motors.
If your layout is a simple oval track, the 5-meter rule applies to prevent voltage drops.
However, complex layouts such as the ones with turnouts and reverse loops would need additional wiring.
For example, modelers use insulated joiners to prevent short circuits on reverse loops.
Remember that complex track usually requires complex wirings. That’s why it is good to have separate wiring for these parts of the layout.
One thing to also note is that there are three-rail tracks such as the ones from Lionel. These tracks are designed to prevent short circuits.
There is no need for additional wirings on these tracks since they are already designed to prevent short circuits.
However, for most tracks, adding separate wiring for things like reverse loops is necessary to avoid short circuits.
What’s next? Did you know that many celebrities made large layouts, such as Frank Sinatra, who had a room specifically for his train layout? To find more famous people who are into model trains, please check this post: 30 Famous People Who are Into Model Trains.