HO started as Half-O scale, running on 16.5mm gauge track, the same as is used for British OO models. HO comes out to a scale of 1:87, and the European models as smaller then similar British OO models, however the much larger North American prototypes will fit within most OO size clearances and operate on most British outline layouts.

We also have a range of Irish locomotive models from Murphy Models which are listed with the British OO locomotives.