How is a limited edition model made?

What is actually involved in making a locomotive for RAIL EXCLUSIVE? It can be a complex
procedure so, with the help of Bachmann’s PR department, we decided to show you what happens
by following a model from concept, through its manufacture in China and on to final delivery.

FIRST COMES THE SUBJECT choice, which is the easy part, or at least you’d think so. You would be forgiven for thinking that selecting a locomotive to produce is a simple task but in fact a tremendous amount of thought goes into the decision, especially since commissioning such an item represents a hefty investment stretching well into five figures. We employ an unscientific combination of ‘gut feel’, looking for gaps in the market, customer requests, and a slice of contemporary chatter. The latter is, of course, widespread when a new colour scheme makes its debut however, new doesn’t necessarily translate into a good choice! You can always add enthusiasm or tip-offs from freight or passenger operating companies into the mix.

The second, much more protracted stage, comprises all the hard work involved with the model’s manufacture which begins – in the case of Bachmann – with the presentation of a research package. Typically this includes drawings, measurements and photographic records as well as descriptions of any detail options. Using this material, design engineers based in Kader Industries’ Hong Kong headquarters create or modify engineering drawings that are used to produce the necessary injection-moulding tools.

From on-site measurements provided in a research package by the RAIL EXCLUSIVE team, engineering drawings and CAD images are created in Kader’s design office, ready to be translated into three-dimensional tooling.


Into the tool room

As its name suggests, the tool room is where the tooling is made. The tools, or moulds, are machined from steel using computer control for accuracy and will be used in high-pressure injection moulding machines to make the various plastic components that go into a locomotive. Treated well, these heavy blocks can have a life span of up to 40 years. When tool-making begins, or ‘metal is cut’, the point of no return is passed as the process is extremely costly to reverse. The tooling alone for a locomotive can cost in excess of £200,000.

Modern tooling design allows options in the form of ‘slides’. These literally slide into the main part of the tool and allow alternative detail – such as grilles or roofs – to be catered for. On our Class 37s, for example, slides are used for the nose and cantrail grilles, which can show a number of different combinations depending on the actual loco being portrayed.

A new set of tooling for a locomotive takes about three months to create although simpler work, such as new slides, is much quicker. Once completed, test shots begin and the first Engineering Prototype sample (EP1) is produced. This plastic moulding is checked to ensure that the sample matches the specification and accurately portrays what it should. At this point revisions and observations will be made along with any corrections considered necessary. Further EP samples may be sent backwards and forwards between China and the UK, until everyone is happy. Progression to an EP2 sample is then made which is flown to the UK for formal approval.


This is what a steel tool for a model locomotive bodyshell looks like – the heavy construction is needed to take the high pressures involved when injecting molten plastic. The first unpainted ‘engineering prototype’ samples are checked for accuracy.


Coats of many colours

The next step is the research and preparation of the livery to be carried on the model. RAIL EXCLUSIVE works closely with Bachmann’s team of graphic artists to produce a number of colour layouts, essentially computer-created files that can be turned into paint masks and printing pads. Care must be taken though, as even simple liveries can include wide variations, making each locomotive unique. It may be something as simple as the unusual positioning of a warning flash through to the unofficial painting of a bufferbeam. These coloured layouts or line drawings, covering all elevations, mark out the various colour boundaries and logos that go towards making up the finished paint scheme. Commonly, there are ten or so shades of paint to specify with over 30 logos to position, ranging from large bodyside company brandings right down to the smallest fuel gauge labels. The initial artwork is double-checked for accuracy before being sent to Hong Kong where it is converted into production artwork that can be used at the factory. Bachmann’s art department then takes one last look for any final discrepancies before authorisation is give to proceed with painted samples.

Decorated samples

Back at the factory in China, the first decorated samples are now produced. Specialist paint masks will have been created for the main base colours whilst smaller logos and lettering are transformed into printing plates for use in the ‘tampo’ printing process. Sent back to the UK for examination, the samples’ colours are compared against reference paint chips and printed logos are checked for position, reproduction and registration. Any adjustments or corrections are noted and reported back to the factory before the main production run of the model can proceed. It may seem like an overly complicated and time-consuming process at times, but it is essential that any errors are spotted before production starts and there’s no going back.


The paint goes on… From left to right: Spray painting on an industrial scale; a section of a colour layout with annotations pointing out specific details or instructions; Rows of ‘tampo’ pad printing machines apply smaller numbering and lettering.


Once production has been approved, the process of assembling all the required components begins.  Each plastic or metal part has to be made and items such as motors manufactured. Some locos require up to 30 different tools. Bringing all these items together can take up to 12 weeks, and it is not until the very last component has been completed that the task of trial assembly can be contemplated. If something is missing, the proving sample has to be held back until everything is available, as it is no good starting the assembly process until all items are ready for the production lines. It is during the component production stage that bodyshells have their livery applied using spray-painting masks and tampo printing equipment. The factory has more than 1,000 of these paint pad machines that are used to reproduce complex detail. The high number is not surprising when one considers that every different colour requires a new application!

Mass production

Providing work for 3,800 staff, the Dongguan factory has 40 production lines to feed and these produce everything from ‘N’ gauge to ‘G’ scale products. However, these lines are not like those found in automated factories that can turn out thousands of items an hour. Model railway products have to be carefully hand-assembled, passing through various stages needed to build up each item. For the Class 37 this would include jobs like fitting the radiator fans and glazing to the bodyshell. The chassis is even more complex with a number of sub-assemblies coming together including bogies, drive-train and the printed circuit board. It’s a big operation with anything up to 500 diesel locos models being put together on one of the lines every day.

When assembled, each loco is quality inspected and given a trial run in each direction on the test track benches. Only after passing rigorous inspection can the model move to the packing area. Just as the components for the model itself have to be assembled before production commences, the same is true of the packaging. Box, product holder, insert and labels, together with instruction leaflets and warranty, are brought together with the locomotive. After packing into its display box and sleeve, and given a protective layer of tissue paper, each finished item is then packed with three identical models in a cardboard carton. These then fill double-wall shipping boxes, which are subsequently packed into the ultimate box, a 40ft ISO container! A short road journey to the port is next before being loaded onto a container ship for the 6,000-mile 28-day sea voyage to the UK.


Production line progress as Class 37 bodies are mated with their chassis. Following inspection and testing the models are carefully packed before being boxed and loaded into a container ready for their 6,000-mile journey.

The final chapter of the story sees the container arrive at a British port after which it is transported to Bachmann’s warehouse in Barwell but only after completing customs and paperwork clearance. It’s then out of one truck and into another for the short journey across Leicestershire to RAIL EXCLUSIVE’s headquarters. Here, the models are speedily repackaged and dispatched by mail, ready to take pride of place on your layout or display shelf.

Thanks are due to Bachmann Europe and Kader Industries for assistance with this article.

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