HOn3½ gauge

HOn3½ scale
Scale	3.5 mm to 1 ft
Scale ratio	1:87
Model gauge	12 mm (0.472 in)
Prototype gauge	3 ft 6 in (1,067 mm)

HOn3​¹⁄₂ gauge represents the modelling of 3 ft 6 in (1,067 mm) gauge railways in HO scale, resulting in a model track gauge of 12 mm (0.472 in) (the same as HOm and TT scale). Trains are operated using direct current or Digital Command Control over realistic-looking two-rail track.

The prototypical Narrow Gauge railways that use the 3 ft 6 in (1,067 mm) gauge can be found in New Zealand, South Africa, Indonesia, Australia, Taiwan, South Africa, Japan and others. A number of these countries run rather significant operations on this gauge, and models can depict anything from small branchline to heavy haulers. Manufacturers of Australian outline models in this size include Haskell, Wuiske Promotions, Black Diamond and PGC, as well as Hollywood Foundries for mechanisms. CMD models and SARModel produce South African HOn3.5 models. Most Japanese and Taiwan HO scale models are made to run on 16.5mm gauge track and are made to 1/80 scale (Tomix, Kato and Tenshodo for Japan being the main brands and Haskell for Taiwan) but some small volume HOn3.5 kits and brass models are made for Japan with Imon being a major supplier.

Related Scales

In the same scale standard gauge trains are modelled on 16.5 mm (0.65 in) gauge track, known as HO scale. Sn3½ is also used to represent 3 ft 6 in (1,067 mm), as the gauge is the same as HO scale. HOn3 uses 10.5 mm (0.413 in) gauge to represent 3 ft (914 mm) gauge railways HOe uses 9 mm (0.354 in) gauge, as does HOn30, to represent railway with gauges of about 750 mm (2 ft 5 ¹⁄₂ in).

See also

• Rail transport modelling scales
• Model railway scales