Model Railroading > Question on meaning of HO, N, O, etc.

Hope this is not a stupid question and I don't know if it has ever been answered on T.O.  I am an HO modeler and have been for over 50 years.  BUT...What does the letters HO stand for in HO gage?  How about O gage, N gage, S gage, etc.  Any one know?

HO= Half O (in theory).Not sure of the others.
Regards,dK.

There was O scale at 1/4" to the foot meaning 1/48 actual size. In Europe they added OO or as double O set at 1/8" to the foot or 1/96 actual size. Someone decided they wanted 3.5mm to the foot and called it HO for half O. They, including NMRA,and set it to run on available OO track. It is not 1/8" to the foot but is 1/87 actual size.



Edited 1 time(s). Last edit at 01/02/19 15:59 by fbe.

N is for nine millimeters between the rails.

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Gauge and scale are two different things.  Gauge is the distance between the rails.  Scale is the relationship to the prototype.  The mess occurs because of British versus American prototype track gauges and because of translations between metric and English measurements. 0 gauge is zero gauge - not oh gauge.  It is 1-1/4 inch between the rails.  Half of 0 gauge is16.5 mm.  16.5 mm. Yes, the numbers aren't the same.  In the 1920s that was good enough.  American standard gauge track using that HO stuff results in a SCALE of 1/87.5.  England standard gauge track is the same, BUT in 1920 motors for correctly scaled models of such tiny prototypes (compared to American prototypes) resulted in making the SCALE slightly larger to accommodate those motors.

The olde timey track gauges for toy trains were 0, 1, 2, 3.  All expressed in English measurements.  And all suffering translations to metric.  #1 gauge is the size popularized by LGB.  There are several scales of models that run on that gauge.  What used to be H1 and then called C-D is now called S. N gauge results in American models scaled at 1/160 and British models scaled at 1.148. And so forth.  

Sorry to not give an internet style quicky answer.  Well, actually I did.  There's a whole lot more on the relation of gauge to scale out there.

fbe Wrote:
-------------------------------------------------------
> There was O scale at 1/4" to the foot meaning 1/48
> actual size. In Europe they added OO or as double
> O set at 1/8" to the foot or 1/96 actual size.
> Someone decided they wanted 3.5mm to the foot and
> called it HO for half O. They, including NMRA,and
> set it to run on available OO track. It is not
> 1/8" to the foot but is 1/87 actual size.

English/British OO gauge runs on HO scale track (1:87) but the rolling stock for OO gauge is actually a bit bigger i.e. 1:76 scale... pretty silly to be honest...but then the UK loading gauge is smaller than most countries so I think actual HO model versions of UK trains would be a bit on the small side...

British O scale is 7mm to the foot (don't ask me, ask the Brits, why they mixed millimeters and feet), or 1 : 43.5, so it's bigger than American O scale (1/4" to the foot, or 1 : 48). HO is Half O, but it's Half of British O, so it's 3.5 mm to the foot, or 1 : 87. OO scale is 4mm to the foot, or 1 : 76. The Brits model OO scale equipment on HO gauge track, so their equipment is slightly narrow gauge. Fair's fair: we model O scale equipment on O gauge track, which scales to 5-foot gauge. These discrepancies weren't important back in the toy train days, but as the equipment has gotten finer, it's becoming increasingly annoying. Incidentally, back when N scale (1.9 mm to the foot, or 1 : 160) was just getting started in the early 1960s, there was some interest in OOO scale (2 mm to the foot, or 1 : 152).

Winston Hill

HO is half the size of O scale, N is half of HO. upkpfan

> HO is half the size of O scale, N is half of HO.

No it isn't and No it isn't. 
There are several postings above that that explain the gauges and scales.

It would sure be nice if it was that simple.  But that would require a time machine and enough money to beat out Lionel, Ives, Hornby, Marklin, and friends in the world market.  With a side trip back to the French revolution.



Edited 1 time(s). Last edit at 01/05/19 03:42 by Lighter.