Understanding the G Scale track gauge and the variations of five different narrow and standard gauge scales

G scale is BIG.

This huge size was introduced by the German firm LGB in 1968 as a narrow gauge scale of 1:22.5 and created the garden railway craze in Europe and the United States. Not only were they big but the trains, tracks, and accessories were ruggedly built to withstand all kinds of rough handling and weather conditions making them the first model railroads which could be built and operated in the back yard. There is some confusion regarding this scale due to the different sizes from a variety of manufacturers who produce models in scale ranges from 1:20.3 to 1:32 and all described as G scale and all capable of operating on the standard G gauge track width of 45mm (1.77 in.) Adding to the confusion is the necessity to change some of the specifications from metric to the U.S. system of inches and feet meaning that after rounding off we end up with approximations at best. The arithmetic for the LGB scale of 1:22.5 when applied to the constant 1.77 in. track gauge looks like this:

Ratio of 1:22.5 = 1 ft. /22.5 ft. = 12 in. /22.5 ft = .53 in. / ft (approx.) meaning a scale ft. is .53 inches. If we apply this factor to the 1.77 in. standard track width-1.77 in. /.53 in. = 3.3 ft or 39 in. The most common narrow gauge railways in Europe are built to Metre Gauge (track gauge or distance between rails of 1 meter) - 1 meter = 39 – 3/8 in. So LGB trains are built to the European Metre Gauge standards. Here are the other scales and the corresponding relative track width of the constant 1.77 in. G gauge standard:

                
  SCALE	        IN./FT.        TRACK WIDTH
   1:20.3        0.59	          36”
   1:22.5        0.53	          39”
   1:24	         0.50	          42”
   1:29	         0.41	          52”
   1:32	         0.375	          57” 

Notice that although the track gauge is constant at 1.77 in. the relative track width changes for each scale. This is the exact opposite of the way it works for real railroads where the rail spacing determines the track gauge. In real railroading a rail spacing of 4’ 8-1/2” would be standard gauge while a rail spacing of 36” would be 3 foot narrow gauge. In G scale railroading a ratio of 1:32 would be standard while a scale of 1:20.3 would be 3 foot narrow gauge and both scales run on a rail spacing of 1.77 in. Add in the fact that LGB is scaled to the European standard of 1:22.5 (also on track gauge of 1.77 in.) and then try to figure out how to design a model railroad with dual-gauge track. At this point most true-to-scale modelers are probably searching for the aspirin bottle with a trembling hand but to many G scale fans the advantages of this gauge outweigh these drawbacks. The usual approach is to choose standard gauge or narrow gauge and stick to that discipline and never the twain shall meet- as in trying to model both unless you are a devoted and accomplished scratchbuilder.


The Advantages

The rugged construction and large size of G scale make it ideal as a family hobby especially as a garden train even with small children and their rough handling.

This is the only scale that can easily be used inside or outside.

Large scale equipment is much easier to detail and modify.

Installation of DCC and on-board sound systems are not only easier to accomplish but can use the largest speakers for more realistic sound effects.

Locomotives can be self-powered by steam or batteries along with radio control systems or they can pick up electric power from the track.

These trains just look great- when you have freight cars that are between 1-1/2 to 2 feet long they just create an awesome sight.


The Disadvantages

All of those different scales as mentioned above.

An inside layout will require a lot of space.

Expensive


If you decide that G scale is for you then consider the following:

Are you going to model European or American trains? This will determine what type of locomotives and rolling stock will be operated.

Are you going to model narrow gauge (American-1:20.3)(European-1:22.5) or standard gauge (American and European-1:24, 1:29, 1:32)?

Will you build the railroad inside or outside as a Garden Railway?

In either case-How much space is available for the layout?

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