O scale
O scale is a scale commonly used for toy trains and rail transport modelling. Introduced by German toy manufacturer Märklin around 1900, by the 1930s three-rail alternating current O gauge was the most common model railroad scale in the United States and remained so until the early 1960s. In Europe, its popularity declined before World War II due to the introduction of smaller scales.
O gauge had its heyday when model railroads were considered toys, with more emphasis placed on cost, durability, and the ability to be easily handled and operated by pre-adult hands. Detail and realism were secondary concerns, at best. It still remains a popular choice for those hobbyists who enjoy running trains more than they enjoy other aspects of modeling, but developments in recent years have addressed the concerns of scale model railroaders making O scale popular among fine-scale modellers who value the detail that can be achieved.
The size of O is larger than OO/HO layouts, and thus is a factor in making the decision to build an O gauge layout.
Collecting vintage O gauge trains is also popular and there is a market for both reproduction and vintage models.
History
The name for O gauge and O scale is derived from "0 gauge" or "Gauge 0" being smaller than Gauge 1 and the other then-existing standards. It was created in part because manufacturers realized their best selling trains were those built in the smaller scales.In the United States, manufacturers such as the Ives Manufacturing Company, American Flyer, and Lionel Corporation used O gauge for their budget line, marketing either Gauge 1 or 'Wide gauge' as their premium trains. One of the Lionel Corporation's most popular trains, the 203 Armoured Locomotive, was O gauge and ran on tracks with rails spaced 1.25 inches apart. The Great Depression wiped out demand for the expensive larger trains, and by 1932, O gauge was the standard, almost by default.
Because of the emphasis on play value, the scale of pre–World War II O gauge trains varied. The Märklin specifications called for 1:43.5 scale. However, many designs were 1:48 scale or 1:64 scale. Early Marx Trains and entry-level trains, usually made of lithographed tin plate, were not scaled at all, made to whimsical proportions about the same length of an HO scale piece, but about the same width and height of an O scale piece. Yet all of these designs ran on the same track, and, depending on the manufacturer of the cars, could sometimes be coupled together and run as part of the same train.
After World War II, manufacturers started paying more attention to scale, and post-war locomotives and rolling stock tended to be larger and more realistic than their earlier counterparts. This has been reflected in the change of name from O gauge to O scale: gauge describes merely the distance between the rails, while scale describes the size ratio of a model as it relates to its real-world prototype.
Since the early 1990s, O scale manufacturers have begun placing more emphasis on realism, and the scale has experienced a resurgence in popularity, with manufacturers including Lionel, MTH, Atlas, and Williams by Bachmann making O gauge model trains at 1:48 scale.
In the United Kingdom the dominant O gauge manufacturer before World War II was Meccano Ltd. who from 1920 produced a range of clockwork and electric models under the "Hornby" name.
Standards
The differences in the various O gauge and O scale standards can be confusing. O gauge model railroad tracks typically have their rails spaced apart with the United States National Model Railroad Association standard allowing spacings between 31.75 mm and 32.64 mm.Scale and gauge
refers to the size of the model relative to the actual full-sized object being represented, while gauge is the width of the model track. Most commercially produced model track is a compromise between appearance and a trouble-free running surface.Scale
Scale is the ratio of a model dimension to the real life dimension. O Scale in the UK is commonly 1:43.5 or 7 mm to the foot. In continental Europe it is commonly 1:45. 1:43.5 is also used, particularly in France. In the USA, 1:48 is common. The NMRA and the MOROP maintain detailed standards for a variety of scales to help model makers create interoperable models.Gauge
Gauge refers to the distance between the inside edges of the load-bearing rails. Various sizes of track gauge exist around the world and the normal O gauge track represents the Standard gauge of. "O gauge" refers to tracks that are nominal according to older standards of NMRA, current standards of BRMSB and NEM. apart current standards of NMRA. When used as a narrow-gauge track, O gauge allows scales such as 1:32 representing gauge track. 1:20 representing narrow-gauge railways.Regional model manufacturers design their O-scale rolling stock with minor regional scale differences—manufacturers support their rolling stock with track made to the same regional scales, so there is no universal width for O-gauge model track. Models could represent the real-world standard gauge track spacing of by choosing various spacings such as at 1:48 scale, at 1:45.2 scale, at 1:44.8 scale, at 7 mm:1 ft scale, and at 1:43.5 scale. Model makers choose their scale based on many considerations including the existing marketplace, aesthetic concerns and compatibility with existing models.
Wide- or narrow-gauge track
Some O-scale modelers choose to model prototypes at other than standard gauge and follow wide gauge or narrow-gauge railroads. There is no standard for wide- or narrow-gauge model track, and modelers wishing to portray such railway track either build their own, or more commonly accept the shortcomings of appropriately wider or narrower gauge model track., and are the more popular track widths used by indoor enthusiasts modeling narrow gauge. Differences in regional scales give different prototype gauges to these different model track widths.For example, using specially manufactured gauge track, scaled at 7 mm to the foot underneath:
- UK O scale rolling stock, it becomes a narrow-gauge track of, and is referred to as "O 16.5". Modelers portray gauges between and.
- European O scale rolling stock, it becomes a narrow-gauge track of, and is referred to as "Oe" portraying a, and prototype. Modelers portray gauges between 650 mm and 800 mm prototype.
- United States O scale rolling stock, it becomes a narrow-gauge track of, and is referred to as "On 2½".
Om gauge
O-27 gauge
O-27 gauge is variant whose origins are slightly unclear. Some historians attribute its creation to A. C. Gilbert Company's American Flyer, but Ives Manufacturing Company used O-27 track in its entry-level sets at least a decade before Gilbert bought Flyer.The modern standard for O-27, however, was formalized after 1938 by Gilbert, who scaled the locomotives and rolling stock to 1:64 scale. After World War II, this practice was continued by Louis Marx and Company, who used it throughout its product line, and Lionel, who used it for its entry-level trains. O-27 track is spaced at the same width as regular O gauge track, but is slightly shorter in height and has thinner rails than traditional O gauge track. A shim underneath the O-27 track enables the use of O and O-27 track together.
The O-27 name comes from the size of the track's curves. A circle made of eight pieces of standard 45-degree curved O gauge track will have a diameter. A circle made of 8 pieces of 45-degree curved O-27 track is smaller, with a diameter. Full-sized O cars sometimes have difficulty negotiating the tighter curves of an O-27 layout.
Although the smaller, tin lithographed cars by American Flyer, Marx, and others predate the formal O-27 standard, they are also often called O-27, because they also operate flawlessly on O-27 track. Marx may have dedicated its entire line to O-27, but only the Lionel Corporation remains to produce O-27 track and trains. Its tubular rail is a standard of the tinplate era.
Super-O gauge
"Super-O gauge" is a variant whose origin stems from Lionel's desire to create a more realistic looking track and improve sagging sales in the late 1950s.Exact scale standards
Dissatisfaction with these standards led to a more accurate standard for wheels and track called Proto:48 This duplicates to exact scale the AAR track and wheel standards. In the United Kingdom a similar ScaleSeven system exists.The track gauge normally used for O of 32 mm or the near-approximation inch is for Standard gauge approximately equivalent to at 1:48 scale, at 1:45 and at 1:43.5.
Possibly because of the large size of American railroad systems, accurate scale modeling in standard gauge O gauge is rare in the United States, though narrow-gauge modeling is much more common.
Four common narrow-gauge standards exist, and the differences among On3, ''On2, On30, and On18'' are frequent sources of confusion. On3 is exact-scale 1:48 modeling of gauge prototypes, while On30 is 1:48 modeling of gauge prototypes, On2 is 1:48 modeling of gauge prototypes, and On18 is 1:48 modeling of gauge prototypes. On30 is also sometimes called On2½.
Because On30's gauge closely matches that of HO track, On30 equipment typically runs on standard HO scale track. While many On30 modelers scratchbuild their equipment, commercial offerings in On30 are fairly common and sometimes very inexpensive, with Bachmann Industries being the most commonly found manufacturer.
Hobbyists who choose to model in any of these O gauge standards nevertheless end up building most, if not all, of their equipment either from kits or from scratch.