Z scale

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Z scale
Scale 1.385 mm to 1 ft
Scale ratio 1:220
Model gauge 6.5 mm/​0.256 in
Prototype gauge 1,435 mm (4 ft 8 12 in) standard gauge

Z scale (1:220) was introduced by the Märklin company in 1972, and is one of the smallest commercially available model railway scales with a track gauge of 6.5 mm/​0.256 in. Z scale trains operate on 0-10 volts direct current (DC) and offer the same operating characteristics as all other two-rail, direct-current, analog model railways. Z scale locomotives can be retro-fitted with microprocessor based digital decoders for digitally controlled model railways. Model trains, track, structures, and human/animal figures are readily available in European, North American, and Japanese styles from a variety of manufacturers.


The sugar-cube sized electric motor in a Z scale model locomotive. The entire engine is only 50 mm (1.97 in) long.

Z scale was introduced by the German model train manufacturer Märklin in 1972 at the Nuremberg Toy Fair. It was the brainchild of Helmut Killian, Märklin's head design engineer at the time. The letter Z was chosen to designate the new scale, as it was thought, at the time, that there would not be a commercial model railway scale even smaller than Z, in the future - hence, the last character of the alphabet in the German and English languages. Since 1972, there have been attempts to bring even smaller scales to the market, but they remain niche products without a wider following at this time (the largest market being T gauge at 1:450 scale, aka 3 mm gauge, designed in Japan and manufactured in China).

In 1978, a Märklin Z scale locomotive pulling six coaches made its entry into the Guinness Book of World Records by running nonstop 1,219 hours, and travelling a distance of 720 km before the train stopped due to failure of the motor.

Z scale, at its inception, was predominantly a European scale, but it has an increasing number of loyal followers in other parts of the world. There are now also manufacturers in North America and Japan/China, among others. Z scale enthusiasts throughout Europe, North America, and Japan participate regularly at most national and regional model railroad exhibitions and shows, where they have demonstrated the outstanding operation and layout design characteristics of the scale. While prices were initially higher for Z scale products (particularly locomotives) compared with those available in larger scales, as volume production, computer-aided design and manufacturing techniques, and the number of competing manufacturers increased, prices have come down to a point comparable to those of high-quality models in any scale. In Z scale, there are no cheap, low-precision models as can be available in larger scales - if they were not designed and manufactured to high standards of precision, they would not run at all.

As early as 1988, Märklin announced their intention to offer digital train control systems in Z scale, and Märklin's 1988 Z scale product catalog listed three locomotives with a built-in digital decoder. However, the technology was not developed enough, and the manufacturer had to cancel these plans, mainly due to heat dissipation problems in locomotive decoders. Since then, these problems have been solved, Z scale has embraced advanced electronics (e.g., microprocessors originally developed for cell phones, surface-mount technology, etc.), and an increasing number of modellers have converted their locomotives to use third party digital model train control systems.

The first attempts to use digital system in Z scale were based on NEM standard, Selectrix, which offered the smallest decoders in the market, with thicknesses of less than 2 mm. German company Müt brought also the first digital control central unit designed specially for Z scale in the market in the early 2000s. Use of the universally popular National Model Railroad Association (NMRA) Digital Command Control (DCC) standard has expanded substantially in Z scale recently as locomotive decoders with sizes comparable to the sizes of smallest Selectrix decoders have become available.

Z scale is now a legitimate, mature modelling scale, with model locomotives, rolling stock, buildings, signalling and human and animal figures becoming available in increasing numbers from an expanding variety of established and particularly smaller, fast-growing manufacturers. Z scale layouts have been winning local, regional, and national level competitions, such as best of show at the NMRA National Train Show (NTS) in July, 2001, in St. Louis, MO.[1]


A "night shot" of a coffee-table sized Z scale layout

The diminutive size of Z scale makes it possible to fit more scale space into the same physical layout as would be used by larger-scale models. Z scale can also be beneficial when there is a need to build very compact train layouts, such as novelty setups in briefcases, guitar cases, or jewellery boxes. Several transportation museums, for instance, have used Z scale to present real world railway scenes. Z scale allows longer trains and broader, more realistic curves than is practical in larger scales.


"Val Ease East" division yard scene showing scratch-built Russell snow plow and detailed Mogul on the turntable.

Due to the small size of Z scale and, in particular, the low weight of the locomotives (a small Z scale engine can weigh as little as 20 g (0.71 oz)), it can be challenging to ensure reliable operation. In particular, the track must be kept clean, as minuscule particles of dust, dirt, or corrosion can easily stop locomotives. Poorly-installed trackwork can be a source of consistent derailing of rolling stock (although this is true, to some extent, in any scale). All of this can create issues for modellers who are interested in prototype operations – in particular, switching.

The low weight of Z scale locomotives contributes to their difficulty pulling trains up grades. In practice, the grade should be kept rather moderate, so, for trains of reasonable length (up to 6-7, four-axle cars for each locomotive), a two-percent grade is about the maximum for reliable operation - for shorter trains, it is possible to go up to four-percent grades. Pulling power of locomotives can be increased by use of traction tires, or adding weight, but, due to the limited internal space available, it is vital that the weighting material have as high a density as possible; tungsten powder (used in metal golf club driver heads) and lead are popular choices.[2]

The smaller market for Z scale results in a limited range of available products both for rolling stock and accessories—with cottage industries meeting some of the demand.[citation needed]


The inventor of Z scale, German manufacturer Märklin, still dominates the market. Micro-Trains Line (MTL) of Talent, Oregon, has joined Märklin as a major Z scale manufacturer and supplier of Z scale model locomotives, rolling stock, structures, and complete set track systems specializing in North American prototypes. There are a growing number of smaller manufacturers, both in Europe and in North America, of Z scale specialty items such as detail parts, electronics, track-building aids, structures, scratch-building supplies, and tools in addition to rolling stock.

In addition to custom Z scale rolling stock for European, Japanese and North American modelers, the German company Freudenreich Feinwerktechnik (FR) has introduced a complete narrow-gauge Z scale system with 4.5 mm (0.177 in) gauge track, which corresponds to metric gauge in prototype and is designated as Zm scale following the NEM standard scale naming system.

American Z Lines (AZL) is a growing manufacturer producing a variety of highly detailed injection-molded North-American prototype diesel locomotives and rolling stock as well as limited-run brass model steam and diesel locomotives.

Rokuhan from Japan has also released a line of Z scale trains, track system and structures.

See also[edit]


  1. ^ Photo, 2001 NTS Best of Show, NMRA.org and Jeffrey MacHan
  2. ^ Improving Locomotive Traction, Zscale.org

External links[edit]