How tall is a Lego train on a track?

Question

I cannot currently access any Lego trains, and the product range offered in the trains category in these years is rather ... disheartening. Nonetheless, I do not rule out the possibility that things might look brighter again in the years to come, in time for my children to still enjoy Lego railroads.

While picking/modifying some furniture for my children's rooms, I would like to make sure the clear height undernearth is just sufficient for minifig-scale trains to pass through, so as to not obstruct any future tracks.

How many centimetres of clear space do I have to plan for?

Let's restrict this a little bit so it becomes a more well-defined question:

• I do not reckon with minifigs or anything else standing on the roof of trains.
• Fixed "installations" should be "usable", though - that is, the height of pantographs should be measured in such a way that they look "realistically extended"; neither completely retracted nor extended as far as the hinges allow.
• The train should be measured while standing on the tracks, but without anything else underneath (i.e. not even a baseplate).

Furthermore, I'd like to suggest a reference list of sets that the answer should be valid for (though, as I'm picking these only visually, without any concrete trains at hand, feel free to suggest deviations or pick equivalent sample trains):

• 4551 - Crocodile Locomotive
• 4558 - Metroliner
• 60051 - High Speed Passenger Train
• 71044 - Disney Train and Station (just the train, obviously)
• 60198 - Cargo Train

Answer 1

LEGO tracks are 12mm high, train wheels go below the true height of the track and so in reality only add 7mm of height.

The structure gauge (also known as clearance) tolerance will obviously be a lot lower than real life. You could perhaps get away with 1/3 a brick clearance but having at least one or two bricks height clearance at minimum is best.

Here are a few measurements for different types of trains.

Model	Name	Studs	Centimetres	Inches
	Amtrak Superliner	17.9	14.4	5.7
	4551 (Pantograph extended)	16.3	13.1	5.1
	Double-Stack Cart	12.8	10.2	4.0
	Early Steam Locomotive	12.4	9.9	3.9

I have used Bricklink Studio to render and calculate these measurements. The models used can all be found in the model library.

Dimension and weight statistics for models can be displayed under Tools > Mode Information so if you can find a model for the train you are interested you can check using this software.

Answer 2

Several of the trains include a diagram showing their size:

It obviously varies somewhat from train to train. Somewhere around six inches or 16cm should be sufficient for most trains.