The term HOn30 (and sometimes HOn2½) is generally used when modelling American prototypes while H0e is used for European prototypes. In the Britain the term OO9 is sometimes used. All these terms refer to models of narrow gauge railways built to the world's most popular model railway scale of HO (1:87) but using a track gauge of 9 mm (0.354 in)—the gauge used for N scale models of standard gauge railways. OO9 refers to OO scale, 1:76.2, models on 9mm gauge track. Although the track gauge is 9mm, sometimes N scale track per se is not used because the ties or sleepers are out of scale and too close together. HOn30 track is available.
Chivers Finelines Forney 2-4-4, built by Peter Bartlett
|Scale||3.5 mm to 1 foot|
|Model gauge||9 mm (0.354 in)|
|Prototype gauge||2 ft (610 mm)
HOn30 is often used to model the 2 ft (610 mm) gauge railroads in the US state of Maine. The first HOn30 / HOn2½ RTR brand introduced in the US was the AHM MinitrainS, initially manufactured by Egger-Bahn and later by Roco and Mehanoteknika Izola, also known as Mehano.
Perhaps the most fascinating part of HOn30 is that RTR models are still scarce. One exception is The MinitrainS line that has recently been upgraded.
Egger-Bahn Steam Tram
|Scale||3.5 mm to 1 foot|
|Model gauge||9 mm (0.354 in)|
|Prototype gauge||760 mm (2 ft 5 15⁄16 in)
H0e is a gauge defined by Normen Europäischer Modelleisenbahnen (NEM). According to that standard, H0e represents narrow gauges between 650–850 mm (25.59–33.46 in), though it's often used to represent 600 mm (1 ft 11 5⁄8 in) gauge railways as well. In strict scale H0e represents a theoretical gauge of 783 mm (2 ft 6 13⁄16 in), which does not exist as a prototype. But this is very close to the gauge of the 750 mm (2 ft 5 1⁄2 in) gauge railways most widely used in Germany, 760 mm (2 ft 5 15⁄16 in) gauge railways Bosnian gauge most widely used in the former Austro-Hungarian empire, 800 mm (2 ft 7 1⁄2 in) gauge rack railways in Switzerland as well as to the 2 ft 6 in (762 mm) gauge used in parts of the British Empire.
In 1965 Bob Hayden and Dave Frary stumbled upon an Associated Hobby Manufacturer’s AHM "MinitrainS" HOn2½ (now named HOn30) train set at a Woolworth's department store. It looked like the perfect way to model the Maine 2-foot railroads in HO scale.
The AHM MinitrainS line came along just a couple of years after N scale appeared in Europe. Minitrains was North American prototype HO scale, using N gauge track. AHM offered two industrial locomotives, a Plymouth diesel and a Baldwin steam locomotive.
Bob and Dave used the AHM trains to model a HOn2½ 3' x 5' portable model railroad called the Elk River Line. The layout appeared in articles starting in the April 1970 issue of RMC.
Their next HOn2½ layout was called Thatcher's Inlet. It was a 6’ x 30" shelf-type switching layout. It was inspired by the Wiscasset waterfront of the Maine 2-foot railroads. The equipment was based more on available N gauge products than on the AHM MinitrainS line - it reflected the growing variety of N gauge equipment and accessories available in the early 1970s.
Next came Dave Frary's 12' x 26' HOn2½ Carrabasset & Dead River Ry (C&DR). It was the first large model railroad to utilize HOn2½. It appeared in the Nov 1979 and Feb 1980 issues of MR.
During the mid-1970s a Japanese company, Sango, made a kit for a 2-6-0 Baldwin engine which showed a great improvement in running ability. This started a growing interest in HOn2-1/2 in Japan. From 1978 to 1982, Joe Works, Sango, and Flying Zoo kits and built-up brass models came on the scene. There was a thriving interest in 2-footers in Japan, using N gauge track. You could put a lot of HO scale operation in a limited space.
In 1974 Bob started his own version of the C&DR. Its first engine was a reworked AHM MinitrainS steamer. The first C&DR road diesels, No. 25 and 26, were based on Minitrix N gauge Fairbanks-Morse switchers. Bob's C&DR was featured in MR’s Great Model Railroads 1991 annual.
Both of these layouts are now gone, but HOn30 is still alive and well with a large community of model railroaders enjoying this unique scale and gauge combination around the world.
The other NEM defined narrow gauges for H0 scale are H0m (using 12 mm/0.472 in gauge originally TT scale track) for models of 1,000 mm (3 ft 3 3⁄8 in) gauge and similar prototypes and H0i (using Z scale 6.5 mm/0.256 in track - also known as H0f) for prototypes around 600 mm (1 ft 11 5⁄8 in)- the most popular gauge for industrial (or Feldbahn) railways.
In the United Kingdom where the most popular railway modelling scale is 1:76 designated 4 mm scale. The narrow gauge equivalents to H0e and H0m are OO9 and OO12. For modelling 3 ft (914 mm) gauge railways – widely used in Ireland and the Isle of Man – a 12 mm (0.472 in) gauge track (as for H0m) is used. For modelling the same 3 ft (914 mm) track in HOn3 or OOn3 – widely used in the United States – the track is 10.5 mm (0.413 in).
The following table lists the most popular narrow gauges in HO and OO scale:
|Name||Scale||Model gauge||Prototype gauge||Used in|
|H0p||1:87||4.5 mm (0.177 in)||300 to <400 mm||Continental Europe|
|H0f (H0i)||1:87||6.5 mm (0.256 in)||400 to <650 mm||Continental Europe|
|HOn2||1:87||7 mm (0.276 in)||2 ft (610 mm)||Americas|
|HOn30 (HOn2½)||1:87||9 mm (0.354 in)||2 ft 6 in (762 mm)||America|
|H0e||1:87||9 mm (0.354 in)||650 to <850 mm||Continental Europe|
|OO9||1:76||9 mm (0.354 in)||2 ft 3 in (686 mm)||British Empire|
|HOn3||1:87||10.5 mm (0.413 in)||3 ft (914 mm)||America|
|H0m||1:87||12 mm (0.472 in)||850 to <1250 mm||Continental Europe|
|HOn3½||1:87||12 mm (0.472 in)||3 ft 6 in (1,067 mm)||British Empire if scale is 1:87|
|OO12||1:76||12 mm (0.472 in)||3 ft (914 mm)||British Empire|
Model railroaders with layouts and rolling stocks by American standard and usually by British standard use for designation of the scale in English language publications the letter O and not the number 0.
In the British Empire and rarely in the French language for narrow gauge it is written after designation of the scale the model gauge in mm, for example, OO9 or OO6.5 in United Kingdom and H09 rather than H0e or H06,5 rather than H0f in France.
In the British Empire and in the French language it is written sometimes with - (hyphen) or – (en dash) between the scale and the model gauge, for example, OO–9 or H0-9.
|Wikimedia Commons has media related to HOn30 gauge.|
|Wikimedia Commons has media related to HO9 gauge.|
|Wikimedia Commons has media related to H0e gauge.|
- Keith Norgrove. "Narrow Gauge Models in OO9 and OOn3". Parkside Dundas. Archived from the original on 2008-05-15. Retrieved 2008-09-05.
- The HOn30 Home Depot: What is HOn30 – by Bob Hayden and Dave Frary
- The HOn30 Home Depot: AHM Minitrains ancient history
- "NEM 010: Ratio, Scale and Gauge" (PDF). Archived from the original (PDF) on 2007-09-27.
- Egger-bahn: History
- NMRA STANDARDS S-1.2 Standards for Scale Models