What is 2mm scale?

2mm scale (1:152 scale) is an even more accurate version of what we commonly refer to as N gauge. It refers to 2mm of the model being equivalent to 1ft in real-life. 2mm scale is often labelled Finescale N gauge.

But why are regular N gauge engines and tracks not made accurately in the first place?

Regular N gauge is actually fairly accurate. It has a scale of 1:160, this means that the prototype (real-life engine) is 160 times larger than the model. The tracks that N gauge run on have a 9mm gauge (gap between the parallel metal rails), which also equates to a scale of 1:160, so far so good, however, although the gauge is correct, the depth of the rail itself does not fit the scale and is about twice as deep as it would look in real life. This is necessary along with out of scale rolling stock wheel flanges to ensure capable running of the model in such a small scale. This, however, is not the biggest misfortune of N gauge.

British N gauge has a scale of 1:148 despite running on the same 9mm track. What this means is the trains look very slightly oversized for the tracks they are running on. This is a necessary compromise of accuracy and came about because full-size British trains have a smaller loading gauge than trains in continental Europe and the US, (loading gauge is the dimensions of the trains to facilitate bridges etc) therefore models of British prototypes if modelled in the traditional 1:160 scale would be simply too small to fit the mechanisms into so slightly over-sized bodies were adopted.

For most this discrepancy is not that much of an issue. Any dissatisfaction suffered by the slightly out of scale rolling stock is more than forgiven by the fact that modelling in such a small gauge facilitates running full-length trains in a reasonable amount of space like a spare room.

For really advanced modellers though, a solution needed to be sought. Although technically 2mm scale predates N gauge, it is used nowadays to represent mainly British prototypes more accurately. There is no ready to run 2mm scale engines or coaches on the market so the scale is not for the faint-hearted as some adaption or scratch building will be required.

2mm scale tracks have smaller rails measuring just 1mm in depth, so although they look more realistic the functionality of them may well be impaired. In addition to this their gauge is slightly larger too, 2mm scale track has a width of 9.42mm between the rails, less than half a millimetre wider than N gauge but all adds to the realism.

2mm scale is not for everyone, for others though overcoming the challenges must be most rewarding.