The upper level of my two-level layout is all narrow gauge, depicting a portion of the former Denver & Rio Grande Western’s Fourth Division line in southwestern Colorado and northern New Mexico.
What is Narrow Gauge?
The term “gauge” refers to the distance between the rails, which in the US, has been standardized at 4 feet 8 and one half inches (“standard gauge”). However, in the 1800s, many different gauges were built in the US, especially before the Civil War. The inability of one gauge’s equipment to operate on another gauge’s tracks led to standardization in the decades after the Civil War, and to today’s nationwide rail network. “Narrow gauge” is any gauge that is less than standard gauge; the most common was 3 foot gauge, used by the D&RGW and some other early railroads. Today, only a few narrow gauge lines still exist in the US, and are mostly historic tourist lines. Worldwide, many gauges are still in use, including narrow gauges and some “broad gauges”.
In the US, narrow gauge lines were popular in the 1800s because they were cheaper to build. The track could be built with tighter radius curves and fewer tunnels, making construction easier and faster, compared to standard gauge. This made them ideal for penetrating mountainous country into mining camps, and being the first railroad to connect a boomtown to the outside world. However, the smaller gauge dictated smaller cars, and they could not haul as much as a standard gauge car. In addition, any freight that came first by standard gauge rail would have to be transferred, usually by hand, to narrow gauge cars. Ultimately, these unavoidable inefficiencies doomed most narrow gauge lines, so only a few existed after 1900 – many of the survivors being in the mountains of Colorado, where standard gauge construction was just too expensive to justify.
The photo above clearly show the difference between standard gauge and narrow gauge cars. Some track was built as “dual gauge”, where three rails were used, one being common to both gauges. These were in locations where the two gauges met and goods were transferred. After 1900, these locations on the D&RGW included Alamosa, Salida, and Montrose, all in Colorado.
The photo below shows some of the dual gauge or three-rail track outside the shops in Alamosa CO in 1970.
Gauge and Scale
For model trains, sometimes the terms gauge and scale are used interchangeably, but they are not the same. As described above, gauge refers to the distance between the rails and nothing more. Scale refers to the size reduction from the “real” or “prototype” to the model; for HO scale, this means that 1 foot equals roughly 87 scale feet. Other common scales in the model train hobby are O scale (1:48), S scale (1:64), and N scale (1:160).
I model in HO scale, 3’ narrow gauge – usually called HOn3. The photo below shows the relative size difference between standard gauge and narrow gauge cars in my Alamosa yard.
