Model Trains aren't just kids' toys. There are some very serious train hobbyists out there. Their involvement ranges from possession of a single train set to spending hours upon hours and large sums on a substantial and exacting models of a railroads and the scenery through which it passes, called a "layout". These hobbyists, called "railway modelers" or "model railroaders", may maintain models large enough to ride on (Garden Railroading). Modelers may collect model trains, building a landscape for the trains to pass through, or operate their own railroad in miniature.

Layout complexity may vary from a simple circle or oval track to realistic reproductions of real places modeled to scale. To enhance their knowledge and experiences, these serious hobbyists gather at model railroad clubs where they talk the talk and walk the walk of model railroad engineers. These clubs often display models for the public. Young and old love these exhibits. The large scale (garden variety) models are usually hand-built and powered by live steam, or diesel-hydraulic, and the engines are often powerful enough to haul dozens of human passengers. Railways of this size are also called miniature railways.

Scales and gauges

The size of locomotive engines depends on the scale and can vary from 700 mm (27.6 in) tall for the largest ridable live steam scales such as 1:8, down to matchbox size for the smallest in Z-scale (1:220). Recently, another scale that was introduced that is also commercially available, called T Gauge, it is 3 mm (0.118 in) gauge track and is a scale of 1:450, basically half the size of Z scale. A typical HO (1:87) engine is 50 mm (1.97 in) tall, and 100 to 300 mm (3.94 to 11.81 in) long. The most popular scales are: G gauge, Gauge 1, O gauge, S scale, HO gauge (in Britain, the similar OO), TT scale, and N scale (1:160 in the United States, but 1:144 in the UK). There is growing interest in Z scale and T Gauge. HO and OO are the most popular. Popular narrow-gauge scales include Sn3, HOn3 Scale and Nn3, which are the same in scale as S, HO and N except with a narrower spacing between the tracks (in these examples, a scale 3 ft (914 mm) instead of the 4 ft 8 1⁄2 in (1,435 mm) standard gauge).

The largest common scale is 1:8, with 1:4 sometimes used for park rides. G scale (Garden, 1:24scale) is most popular for backyard modeling. It is easier to fit a G scale model into a garden and keep scenery proportional to the trains. Gauge 1 and Gauge 3 are also popular for gardens. O, S, HO, and N gauge are more often used indoors. Lionel trains in O scale (1:48scale) are popular toys. S refers to 1:64 scale.

The words scale and gauge seem at first interchangeable but their meanings are different. Scale is the model's measurement as a proportion to the original, while gauge is the measurement between the rails. Your choice of scale has a lot to do with budget and available space. N-Scale is a popular apartment size scale. The key is to stick to your choice once you have decided on a scale, and not mix scales in a single layout.

Couplers and connectors

In addition to different scales, there are also different types of couplers for connecting cars, which are not compatible with each other.

In H0, the Americans standardized on horn-hook or X2F couplers, though these have largely given way to working knuckle couplers which are a close approximation to the "automatic" couplers used on the prototype there and elsewhere. Also in H0, the European manufacturers have standardized, but on a coupler mount, not a coupler: many varieties of coupler can be plugged in (and out) of the NEM coupler box. None of the popular couplers has any resemblance to the prototype three-link chains generally used on the continent.

For British modelers, whose most popular scale is 00, the normal coupler is a tension-lock coupler, which again has no pretense of replicating the usual prototype three-link chain couplers. Bachmann and more recently Hornby have begun to offer models fitted with NEM coupler pockets. This theoretically enables modelers of British railways to substitute any other NEM362 coupler, though many Bachmann models place the coupler pocket at the wrong height. A fairly common alternative is to use representations of chain couplings as found on the prototype, though these require large radius curves to be used to avoid derailments.

Other scales have similar ranges of non-compatible couplers available.

Power Sources

Model railway engines are generally operated by low voltage direct current (DC) electricity supplied via the tracks, but there are exceptions, such as Mrklin and Lionel Corporation, which use alternating current (AC). Modern Digital Command Control (DCC) systems use alternating current. Other locomotives, particularly large models, used steam. Steam or clockwork driven engines are still sought by collectors.

Clockwork

Most early models for the toy market were powered by clockwork and controlled by levers on the locomotive. Although this made control crude the models were large and robust enough that grabbing the controls was practical. Various manufacturers introduced slowing and stopping tracks that could trigger levers on the locomotive and allow station stops.

Electricity

Three-rail

Early electrical models used a three-rail system with the wheels resting on a metal track with metal sleepers that conducted power and a middle rail which provided power to a skid under the locomotive. This made sense at the time as models were metal and conductive. Modern plastics were not available and insulation was a problem. In addition the notion of accurate models had yet to evolve and toy trains and track were crude tinplate. A variation on the three-rail system, Trix Twin, allowed two trains to be independently controlled on one track, before the advent of Digital Command Control.

Two-rail

As accuracy became important some systems adopted two-rail power in which the wheels were isolated and the rails carried the positive and negative supply or two sides of the AC supply.

Stud contact

Other systems such as Mrklin instead used fine metal studs to replace the central rail, allowing existing three-rail models to use more realistic track.

Overhead line

Where the model is of an electric locomotive, it may be supplied by overhead lines, like the full-size locomotive. Before Digital Command Control became available, this was one way of controlling two trains separately on the same track. The electric-outline model would be supplied by the overhead wire and the other model (usually steam-outline) would be supplied by one of the running rails. The other running rail would act as a common return.

Battery

Early electric trains ran on batteries because few homes in the late 19th century and early 20th century had electricity. Today, inexpensive train sets running on batteries are again common but regarded as toys and seldom used by hobbyists. Batterypower is used by many garden railway and larger scale systems because of the difficulty in obtaining reliable power supply through the rails outdoors and because the high power consumption and thus current draw of large scale garden models is more easily and safely met with rechargeable batteries. Most large scale battery powered models use radio control.

Live steam

Engines powered by Live steam are often built in large, outdoor gauges, and are available in Gauge 1, G scale, 16 mm scale and can be found in 0 and H0. Hornby Railways produce live steam locomotives in 00, based on designs first arrived at by an amateur modeler. Other modelers have built live steam models in H0/00, 009 and N.

Internal combustion

Occasionally gasoline-electric models, patterned after real diesel-electric locomotives, come up among hobbyists and companies like Pilgrim Locomotive Works have sold such locomotives. Large-scale petrol-mechanical and petrol-hydraulic models are available but unusual and pricier than the electrically powered versions.

Control

The first clockwork (spring-drive) and live steam locomotives ran until out of power, with no way for the operator to stop and restart the locomotive or vary its speed. The advent of electric trains, which appeared commercially in the 1890s, allowed control of the speed by varying the current or voltage. As trains began to be powered by transformers and rectifiers more sophisticated throttles appeared, and soon trains powered by AC contained mechanisms to change direction or go into neutral gear when the operator cycled the power. Trains powered by DC can change direction by reversing polarity.

Electricity permits control by dividing the layout into isolated blocks, where trains can be slowed or stopped by lowering or cutting power to a block. Dividing a layout into blocks permits operators to run more than one train with less risk of a fast train catching and hitting a slow train. Blocks can also trigger signals or other accessories, adding realism or whimsy. Three-rail systems often insulate one of the common rails on a section of track, and use a passing train to complete the circuit and activate an accessory.

Many layout builders are choosing digital operation of their layouts rather than the more traditional DC design. The industry standard command system is Digital Command Control (DCC). The advantages to DCC are that track voltage is constant (usually in the range of 20 volts AC) and the command throttle sends a signal to small circuit cards, or decoders, hidden inside the piece of equipment which control several functions of an individual locomotive, including speed, direction of travel, lights, smoke and various sound effects. This allows more realistic operation in that the modeler can operate independently several locomotives on the same stretch of track. Less common closed proprietary systems also exist. Several manufacturers offer software that can provide computer-control of DCC layouts.

In large scales, particularly for garden railways, radio control and DCC in the garden have become popular.

Landscaping

Many modelers pay special attention to landscaping their layout, creating a realistic looking imaginary world of their own design or modeling after an actual location, often historic. Landscaping is termed "scenery building" or "scenicking".

Constructing scenery involves preparing a sub-terrain using a wide variety of building materials, including (but not limited to) screen wire, a lattice of cardboard strips, or carved stacks of expanded polystyrene (Styrofoam) sheets. A scenery base is applied over the sub-terrain; typical base include casting plaster, plaster of Paris, hybrid paper-pulp (papier-mache) or a lightweight foam/fiberglass/bubble wrap composite as in Geodesic Foam Scenery. The scenery base is covered with ground cover, which may be ground foam, colored sawdust, natural lichen, or commercial scatter materials for grass and shrubbery. Buildings website and structures can be purchased as prefab kits, or built from scratch from cardboard, balsa wood, basswood, paper, or polystyrene or other plastic. Trees can be fabricated from materials such as Western sagebrush, candytuft, and caspia, to which adhesive and model foliage are applied; or they too can be bought ready-made from specialist manufacturers. Water can be simulated using polyester casting resin, polyurethane, or rippled glass. Rocks can be cast in plaster or in plastic with a foam backing. Castings can be painted with stains to give coloring and shadows.

Weathering

Weathering refers to making a model look used and exposed to weather by simulating dirt and wear on real vehicles, structures and equipment. Most models come out of the box looking new, because unweathered finishes are easier to produce and many collectors want models to look pristine. However, pristine is not the most realistic looking. The wear a freight car or building undergoes depends not only on age but where it is used. Rail cars in cities accumulate grime from building and automobile exhaust, while cars in deserts may be subjected to sandstorms which etch or strip paint. A model that is weathered would not fit as many layouts as a pristine model which can be weathered by its purchaser.

Weathering purchased models is common. At the least, weathering aims to reduce the plastic-like finish of scale models. The simulation of grime, rust, dirt, and wear add realism. Some modelers simulate fuel stains on tanks, or corrosion on battery boxes. In some cases, evidence of accidents or repairs may be added, such as dents or freshly painted replacement parts, and weathered models can be nearly indistinguishable from their prototypes when photographed appropriately.

Conclusion

Clearly, there is a lot more to model railroading as a serious hobby than meets the eye. There is a great investment of time, and yes probably money too, but the good thing is that for many this is a life-long hobby. Well maintained trains and rolling stock will last a life-time and it isn't unusual for trains to get handed down generations. Train collection is, therefore, also very popular among many hobbyists. The next time a model railroad club in your area has a public display, why not go take a look? Chances are you too will get the model railroading bug.