Scales and Gauges Part 9 - Narrow Gauges - On3 On2 On30

Modeling narrow gauges, starting with the "O" scale narrow gauges: On3, On2, and On30 (On2 1/2). Many of the problems with O scale and gauge disappear when modeling narrow gauge railroads. The naming convention for narrow gauge model railroads is to state the scale, then a lowercase n for narrow gauge, and then the prototype gauge in feet or meters. Or in the case of 2 1/2 foot gauges, often stated as 30 inches. The problem comes from mixing standard and narrow gauges in a duel gauge track configuration. A problem arises with standard gauge O scale being usually modeled at five feet with oversized flanges. The gauge and more importantly wheel flanges are accurate in the narrow gauges, or the gauge is, and the flanges and wheels are close to scale. But the gauge and wheels in standard gauge are quite wrong. The flanges are huge. The gauge is wide, or the scale has been adjusted to 1:47 scale or 1:43.5 scale making the standard gauge models off if not incompatible. This makes the switch (points) frogs incompatible on the shared rails. There are cheats in frog design or the ultimate fix is to narrow the standard gauge to prototype 4' 8 1/2" AND narrow the wheels and reduce the flanges on the standard gauge models. A scale called AAR Fine Scale later named Proto 48. On Our MRS railroad, we had a short section of dual gauge at the mills. Our solution was to never run large flanges into this area, using only equipment with flanges the same size as the narrow gauge flanges. AND it was just a stub siding and easy to push cars into. More on Proto 48 next week!