Rail transport modelling

General description

Layouts vary from the very stylistic (sometimes just a simple circle of track) through to the 'absolutely realistic', where scale models of real places are modelled in extreme detail.
One of the largest of these is in the Pendon Museum in Oxfordshire, UK, where a OO model of the Vale of The White Horse as it appeared in the 1930s is under construction. The museum also houses one of the earliest scenic models ever made - the 'Madder Valley' layout built by John Ahern. This layout was built in the 1930s and brought in the era of realistic modelling. Bekonscot in Buckinghamshire is the oldest model village, and also includes a model railway. The largest model railroad track (in scale HO) in the world is Miniatur Wunderland in Hamburg, Germany [1].

Model railway clubs exist for model railway enthusiasts to meet. Clubs sometimes put on displays of models for the general public. One rather specialist branch of railway modellers concentrates on larger scales and gauges, most commonly using track gauges of 3.5 or 5 inches.
Models in these scales are usually hand-built and are powered by live steam, and the engines are often powerful enough to haul humans as passengers.

One particularly famous model railway club is the Tech Model Railroad Club (TMRC) at MIT.

The Philosophy of Model Railways

Whether it is a simple clockwork train on a circular track, or a huge detailed layout run to a timetable with historically accurate signals and train formations, the essence of a model railway is that it presents the appearance of a working railway. It is essentially the pursuance of this appearance which causes people to spend varying amounts of time and money creating a model railway, sometimes making it a lifetime’s project. Anyone intending to make a model railway, however, must sooner or later confront not the similarities between their model and the real thing, but the differences. Unless these differences are accepted and accommodated in some way, the model is unlikely to be successful or satisfying.

Generally speaking, the purpose of a model railway is to be interesting to see and to operate, whether the ‘interest’ depends on historical accuracy, fidelity to the appearance of the original, or complexity of operation. Those models which contain more detail, more track and rolling stock, are generally more interesting. But it is important to remember that this is not the purpose of a real railway. If the railway companies of the past could have implemented a ‘Star Trek’ method of transporting passengers and goods instantly from A to B they would quickly have abandoned the use of trains, which was always an expensive method of transport.
They would never have used more locomotives or coaches than was essential to maintain their traffic, and certainly they would never have built and maintained ‘interesting’ and complex track formations, which were notoriously expensive, without first making every effort to simplify them.

There is another essential difference to be dealt with.
Even the largest model railway cannot model an entire line, unless it be a cliff or miniature line. Most if not all interesting lines would ‘go off’ somewhere to connect with the rest of the system. Even a very large layout must compromise, therefore with the need to ‘disappear’ off the edge of the modelled world.

Many modellers begin with the urge to see trains running as soon as possible, and rush into the first type of layout that occurs to them.
Many of them find too late that they have committed themselves to a design which is not going to interest them for long, or they see when halfway into construction that they would have been better to adopt a different plan, even to model a different railway altogether.
Successful and satisfying layouts are almost always the result of a considerable amount of planning involving compromise and tradeoffs.
This can be frustrating at first, though it can become an enjoyable pursuit in itself, but the results of a well-planned layout are usually well worth the time and effort involved.

The first stage in planning is to decide what sort of layout is wanted.
All is not what it seems here, for though a large layout may seem more interesting to a beginner, it is likely to prove too exhausting in its construction and operation to be truly satisfying.
On the other hand, someone who is determined to be historically accurate above all may spend an enormous amount of time in the construction of a layout which in reality had only three or four trains per day, using at the most two locomotives.
It is therefore very important to decide first what one wants from a layout. Common themes include historical accuracy, detailed modelling, and operations. One popular approach is to choose a locale and a period in history, for example Virginia in the 1940s or New Mexico in the 1960s.

For many years the most popular form of layout was the ‘continuous run’, evolving from the simple ‘trainset’ or ‘toy train’ circuit of track.
The advantage of this layout is that the trains do indeed run continuously, and a train can be seen running for a period of time not greatly reduced from that of a real train journey.
It also avoids the need to have a ‘rest of the world’ located offstage somewhere.
The disadvantage, however, is that it is most unrealistic.
No real train appears again from the same direction after a few seconds! Modellers who really wish to see main line trains run for lengthy periods, however, may suspend their disbelief, or compromise with this aspect of the model, in the interests of getting what they want.

The other extreme from this type of layout is the ‘branch line terminus’, also known as a point-to-point line.
The advantage of this layout is that while simple to operate and requiring few locomotives, it is realistic in operation. The trains arrive and depart like a real branch-line train.
Much satisfaction can be gained from the inclusion of a small goods yard and the visit and shunting of the daily goods train.
The disadvantage is that all the rolling stock must have an ‘elsewhere’ to go to, off the layout, representing the ‘rest of the system’.
This is commonly known as a ‘fiddle yard’ where all traffic intended to run onto the layout is assembled by hand, and of course this requires extra space, often as much as the ‘real’ or modelled part of the layout.
Another disadvantage is that the operation can become very unvaried after a while.
Modellers whose urge to start a layout came from watching long expresses racing by will not find this very satisfying.

Many layouts follow a middle course, and model a stretch of line with ‘rest of the world’ at both ends. This is both realistic and satisfying to watch.
Here too, though, there are disadvantages: two ‘fiddle yards’ are required, one at each end, and the amount of rolling stock required to represent a realistic selection of traffic is considerable. The modeller with time and space to spare will, however, find this a source of satisfaction.

To decide which layout to build requires some decision as to the 'philosophy' of one’s railway, and time spent thinking over the alternatives and their relative merits will be a good investment.
The design, size and character of a layout can be very different according to what aspect of railways interests the modeller.
Some are interested mainly in highly detailed scenery and buildings, realistic trackside vehicles and figures, others may be interested in signalling, and will want a fully signalled layout.
Others will be happy with no signals at all, however unrealistic this appears. Most modellers seem to prefer locomotives in action above all else, and the other aspects of the model take a backward place.
Whatever it is, much time and effort will be saved in construction if this is decided in advance of starting.

Methods of power

Although DC power with the positive and negative charges on the two rails is the most common method of power, Märklin and Lionel use AC power on a three-rail system where the middle rail is powered and the outer rails act as a common, or ground. To eliminate the unrealistic appearance of the third rail, Märklin conceals the rail as studs in the track. American Flyer is another exception, which used AC power on two-rail track.

Early electric trains ran on battery power, because few homes in the late 19th and early 20th centuries were wired for electric power. Today, inexpensive train sets running on battery power are once again becoming more common, but these are generally regarded as toys and are seldom used by hobbyists.

Model railways in the early twentieth century ran using wind-up clockwork or miniature steam engines instead; and steam or clockwork driven engines are still sought by collectors.

Live steam is readily available in G scale and can be found in O and H0 scale. Hornby Railways produce a live steam locomotive in OO scale, development of work by some very dedicated modellers who hand-built live steam models in HO/OO and N, and there is even one in Z in Australia.

Occasionally the topic of gasoline-electric models, patterened after real-life diesel-electric locomotives, comes up among dedicated hobbyists, but these locomotives are not commercially available.

Control

Electric power also permits control by dividing the layout into electrically isolated blocks, where trains can be slowed or stopped by lowering or cutting the power to a block. Dividing a layout into blocks also permitted operators to run more than one train on a layout with much less risk of a fast train catching up with and hitting a slow train. Blocks can also trigger signals or other animated accessories on the layout, adding more realism (or whimsy) to the layout. Three-rail systems will 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 modern day model railways use digital techniques and are computer controlled. The industry standard command system is called Digital Command Control, or DCC. Some less-common closed proprietary systems also exist.

Scales and gauges

G scale because of its larger size is most often used for outdoor modelling. It is easier to fit a G scale model into a garden landscape and still keep the scenery proportional to the size of the trains running through. O, HO, and N gauge are more delicate due to their size and are used more often indoors.

The words scale and gauge seem at first to be used interchangeably in model railways, but their meanings are different. Scale is the model's measurement as a proportion to the original, while gauge is the measurement between the two running rails of the track.

At first, model railways were not to scale. Manufacturers and hobbyists soon arrived at de facto standardss for interchangeability, such as gauge, but trains were only a rough approximation to the real thing. See NEM and NMRA. Official scales for the various gauges were soon drawn up, but the scales were not at first at all rigidly followed, and were not necessarily correctly proportioned for the rail gauge chosen. O (zero) gauge trains, for instance, operate on track that is too widely spaced, while the British OO and N standards operate on track that is significantly too narrow. Most of the commercial scales also have standards that include wheel flanges that are too deep, wheel treads that are too wide, and rail tracks that are too large.

Later on, groups of modellers became dissatisfied with these inaccuracies, and developed finescale standards in which everything is correctly scaled. These are used by dedicated modellers but have not generally spread to mass-produced equipment.

The most common scales and gauges in Europe and the USA are:

Model railway manufacturers